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1421 lines
24 KiB
Markdown
1421 lines
24 KiB
Markdown
# Turbulence Model Atlas Gate
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## Purpose
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Add the classical and modern turbulence-model family tree as an explicit model atlas for the FAMM / NUVMAP / 16D witness stack.
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This document imports turbulence models as **closure/witness gates**, not as solved proof objects. The goal is to let the Warden choose, compare, scar, or hybridize turbulence models by region rather than treating the turbulence-model hierarchy as a single fixed ladder.
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```text
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flow region
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→ model-family candidate
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→ closure assumptions
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→ physics retained
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→ CPU / memory cost
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→ unresolved residual
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→ witness strength
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→ FAMM scar or promotion
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```
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## Warden boundary
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Allowed claim:
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```text
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The stack now has an explicit atlas of turbulence model families and can reason about their closure assumptions, cost/physics tradeoffs, residual risk, and 16D witness requirements.
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```
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Disallowed claim:
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```text
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Adding the atlas proves a better turbulence closure, beats DNS/LES/RANS benchmarks, or solves Navier-Stokes regularity.
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```
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Hard rule:
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```text
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A turbulence model is a witness projection, not the flow itself.
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```
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## Core taxonomy
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The old chart has a one-axis tradeoff:
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```text
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more physics ↔ less CPU time
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```
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The project atlas expands it to:
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```text
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physics retained
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CPU / memory cost
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closure assumption burden
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wall treatment burden
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unresolved residual
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scar pressure
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witness strength
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region-of-validity guard
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```
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## Global packet
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```math
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\Gamma_{\mathrm{turbulenceModel}}
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=
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(
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X_{\mathrm{flow}},
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\pi_{\mathrm{model}},
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W_{\mathrm{closure}},
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R_{\mathrm{residual}},
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I_{\mathrm{flow}},
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G_{\mathrm{validity}},
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K_{\mathrm{cost}},
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\epsilon
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)
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```
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| Packet term | Meaning |
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| `X_flow` | original turbulent flow region |
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| `pi_model` | projection into DNS / LES / RANS / hybrid / algebraic model |
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| `W_closure` | closure assumption or resolved-scale witness |
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| `R_residual` | unresolved/subgrid/Reynolds-stress residual |
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| `I_flow` | invariant/quantity to preserve: mass, momentum, energy, vorticity, wall shear, spectra, etc. |
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| `G_validity` | assumptions: incompressible/compressible, wall-bounded/free shear, separated/attached, high/low Re, etc. |
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| `K_cost` | CPU, memory, mesh, timestep, solver cost |
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| `epsilon` | model error / closure gap / numerical residual |
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## 0. Exact / near-exact resolution family
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### DNS — Direct Numerical Simulation
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```text
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DNS_EXACT_RESOLUTION_GATE
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```
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Purpose:
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```text
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solve the Navier-Stokes equations while resolving all dynamically relevant scales down to dissipative scales
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```
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Project role:
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```text
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highest-physics reference witness
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brutal cost
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benchmark / calibration source
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not a practical everyday route for high-Re engineering flow
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```
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Warden checks:
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```text
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mesh resolves Kolmogorov scale
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proper timestep / CFL
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numerical dissipation recorded
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boundary conditions recorded
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not called exact if discretization error is unbounded
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```
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### Filtered DNS / under-resolved DNS
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```text
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FILTERED_DNS_WITNESS_GATE
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```
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Purpose:
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```text
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DNS-like equations on a grid that may not fully resolve every scale; useful as data/witness but not full DNS
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```
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Project role:
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```text
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calibration source with explicit resolution scar
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```
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## 1. LES family — spatially filtered turbulence
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### LES — Large Eddy Simulation
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```text
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LES_FILTERED_SUBGRID_GATE
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```
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Purpose:
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```text
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resolve large eddies, model subgrid-scale stresses
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```
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Canonical filtered form:
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```math
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\partial_t \bar u_i + \bar u_j\partial_j\bar u_i
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=
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-\frac{1}{\rho}\partial_i\bar p
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+\nu\partial_{jj}\bar u_i
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-\partial_j\tau_{ij}^{\mathrm{sgs}}
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```
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Subgrid stress:
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```math
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\tau_{ij}^{\mathrm{sgs}}
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=
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\overline{u_i u_j}-\bar u_i\bar u_j
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```
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Project role:
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```text
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resolved-scale witness + subgrid residual channel
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```
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### Smagorinsky SGS model
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```text
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SMAGORINSKY_SGS_GATE
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```
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```math
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\nu_t=(C_s\Delta)^2|\bar S|
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```
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Role:
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```text
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baseline eddy-viscosity subgrid closure
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```
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Scar risks:
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```text
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over-dissipation
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near-wall damping needed
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poor transitional/backscatter behavior
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```
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### Dynamic Smagorinsky / Germano dynamic model
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```text
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DYNAMIC_SMAGORINSKY_SGS_GATE
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```
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Role:
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```text
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computes local coefficient from test filtering rather than fixed coefficient
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```
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Scar risks:
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```text
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coefficient noise
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averaging choices
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negative eddy viscosity / stability handling
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```
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### WALE — Wall-Adapting Local Eddy-viscosity
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```text
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WALE_SGS_GATE
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```
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Role:
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```text
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near-wall LES subgrid model using local velocity-gradient invariants
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```
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Good for:
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```text
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wall-bounded LES without ad-hoc damping in many cases
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```
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### Vreman SGS model
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```text
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VREMAN_SGS_GATE
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```
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Role:
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```text
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algebraic SGS closure designed to vanish in certain laminar/shear cases and behave robustly near walls
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```
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### Sigma SGS model
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```text
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SIGMA_SGS_GATE
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```
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Role:
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```text
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SGS model based on singular values of velocity-gradient tensor
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```
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### One-equation SGS kinetic-energy model
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```text
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ONE_EQUATION_SGS_K_GATE
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```
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Role:
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```text
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transport subgrid kinetic energy and derive eddy viscosity from it
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```
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### Mixed / similarity / Bardina model
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```text
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BARDINA_SIMILARITY_SGS_GATE
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MIXED_SGS_GATE
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```
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Role:
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```text
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use scale similarity and/or combine similarity with eddy viscosity
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```
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Scar risks:
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```text
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stability
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backscatter control
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need explicit residual/witness monitoring
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```
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### Clark gradient model
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```text
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CLARK_GRADIENT_SGS_GATE
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```
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Role:
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```text
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Taylor/gradient expansion of subgrid stress
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```
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### Approximate deconvolution model
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```text
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APPROXIMATE_DECONVOLUTION_SGS_GATE
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```
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Role:
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```text
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approximate unfiltered field from filtered field, then model SGS contribution
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```
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### Coherent Structure / Structure-function SGS models
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```text
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COHERENT_STRUCTURE_SGS_GATE
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STRUCTURE_FUNCTION_SGS_GATE
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```
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Role:
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```text
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subgrid closure based on coherent vortical structures or local structure functions
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```
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### ILES / MILES — implicit LES
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```text
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IMPLICIT_LES_NUMERICAL_SGS_GATE
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MILES_GATE
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```
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Role:
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```text
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use numerical dissipation of the scheme as implicit SGS model
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```
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Warden check:
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```text
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numerical viscosity is the model; it must be measured, not ignored
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```
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## 2. Hybrid RANS / LES and scale-resolving simulation
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### DES — Detached Eddy Simulation
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```text
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DES_HYBRID_RANS_LES_GATE
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```
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Purpose:
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```text
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RANS near attached boundary layers, LES in separated regions
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```
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Role:
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```text
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region-router between modeled and resolved turbulence
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```
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Scar risks:
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```text
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grid-induced separation
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gray-area behavior
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incorrect shielding of boundary layer
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```
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### DDES — Delayed Detached Eddy Simulation
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```text
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DDES_HYBRID_GATE
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```
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Role:
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```text
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DES with shielding to delay LES activation in attached boundary layers
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```
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### IDDES — Improved Delayed Detached Eddy Simulation
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```text
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IDDES_HYBRID_GATE
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```
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Role:
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```text
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improved near-wall / wall-modeled LES and RANS-LES blending behavior
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```
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### ZDES — Zonal DES
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```text
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ZONAL_DES_GATE
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```
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Role:
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```text
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explicitly prescribe RANS/LES zones by region
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```
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### SAS — Scale-Adaptive Simulation
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```text
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SAS_SCALE_ADAPTIVE_GATE
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```
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Role:
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```text
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allows resolved unsteadiness based on local flow scale, often from RANS base model
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```
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### PANS — Partially Averaged Navier-Stokes
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```text
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PANS_PARTIALLY_AVERAGED_GATE
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```
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Role:
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```text
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continuous bridge between RANS and DNS/LES by choosing unresolved kinetic-energy fraction
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```
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### PITM — Partially Integrated Transport Model
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```text
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PITM_PARTIALLY_INTEGRATED_GATE
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```
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Role:
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```text
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scale-resolving hybrid based on partial integration of turbulence spectrum/transport
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```
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### VLES — Very Large Eddy Simulation
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```text
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VLES_GATE
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```
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Role:
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```text
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resolve very-large structures, model more of the spectrum than LES
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```
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### XLES / X-RANS variants
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```text
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XLES_GATE
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X_RANS_GATE
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```
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Role:
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```text
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hybrid scale-resolving variants between RANS and LES
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```
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### WMLES — Wall-Modeled LES
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```text
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WALL_MODELED_LES_GATE
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```
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Role:
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```text
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LES in outer layer plus wall model to avoid resolving viscous sublayer
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```
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## 3. RANS family — Reynolds averaging closures
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RANS decomposes velocity into mean plus fluctuation:
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```math
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u_i = \overline{u_i}+u_i'
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```
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and produces Reynolds stress:
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```math
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R_{ij}=\overline{u_i'u_j'}
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```
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Mean equation:
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```math
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\partial_t\overline{u_i}
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+
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\overline{u_j}\partial_j\overline{u_i}
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=
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-\frac{1}{\rho}\partial_i\overline p
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+\nu\partial_{jj}\overline{u_i}
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-\partial_j R_{ij}
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```
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Closure problem:
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```text
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model R_ij
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```
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### Linear eddy-viscosity / Boussinesq assumption
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```text
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BOUSSINESQ_EDDY_VISCOSITY_GATE
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```
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```math
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-R_{ij}
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=
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2\nu_t\overline S_{ij}
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-
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\frac{2}{3}k\delta_{ij}
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```
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Role:
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```text
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assume turbulent stresses align with mean strain
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```
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Scar risks:
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```text
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anisotropy
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curvature
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rotation
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separation
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secondary flows
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strong strain history
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```
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## 4. Zero-equation / algebraic closures
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### Prandtl mixing-length model
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```text
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PRANDTL_MIXING_LENGTH_GATE
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```
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```math
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\nu_t=l_m^2\left|\frac{dU}{dy}\right|
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```
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Role:
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```text
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simple wall/shear eddy-viscosity estimate
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```
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### Cebeci-Smith algebraic model
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```text
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CEBECI_SMITH_ALGEBRAIC_GATE
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```
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Role:
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```text
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algebraic boundary-layer eddy-viscosity model with inner/outer formulation
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```
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### Baldwin-Lomax algebraic model
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```text
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BALDWIN_LOMAX_ALGEBRAIC_GATE
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```
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Role:
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```text
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classic algebraic model for attached aerodynamic boundary layers
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```
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### Van Driest damping / wall damping functions
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```text
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VAN_DRIEST_DAMPING_GATE
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```
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Role:
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```text
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near-wall damping correction for mixing-length/eddy-viscosity models
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```
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## 5. One-equation RANS closures
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### Spalart-Allmaras model
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```text
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SPALART_ALLMARAS_ONE_EQUATION_GATE
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```
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Role:
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```text
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transport a modified turbulent viscosity variable; common for external aerodynamic boundary layers
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```
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Project role:
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```text
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cheap RANS closure with better physical content than algebraic models
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```
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Scar risks:
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```text
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massive separation
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complex recirculation
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strong anisotropy
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non-equilibrium turbulence
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```
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### Baldwin-Barth one-equation model
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```text
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BALDWIN_BARTH_ONE_EQUATION_GATE
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```
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Role:
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```text
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older one-equation eddy-viscosity model for aerodynamic applications
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```
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## 6. Two-equation RANS closures
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### Standard k-epsilon
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```text
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K_EPSILON_STANDARD_GATE
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```
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Variables:
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```text
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k = turbulent kinetic energy
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ε = dissipation rate
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```
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Eddy viscosity:
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```math
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\nu_t=C_\mu\frac{k^2}{\epsilon}
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```
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Role:
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```text
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robust industrial free-shear / many engineering flows
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```
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Scar risks:
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```text
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near-wall treatment
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adverse pressure gradient
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strong separation
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curvature/rotation
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```
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### RNG k-epsilon
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```text
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K_EPSILON_RNG_GATE
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```
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Role:
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```text
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renormalization-group motivated k-epsilon variant with improved strain/curvature behavior in some regimes
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```
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### Realizable k-epsilon
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```text
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K_EPSILON_REALIZABLE_GATE
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```
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Role:
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```text
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variant designed to satisfy certain mathematical realizability constraints on Reynolds stresses
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```
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### Low-Re k-epsilon variants
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```text
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LOW_RE_K_EPSILON_GATE
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```
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Role:
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```text
|
|
resolve near-wall region with damping functions / low-Re corrections
|
|
```
|
|
|
|
### Standard k-omega / Wilcox k-omega
|
|
|
|
```text
|
|
K_OMEGA_STANDARD_GATE
|
|
```
|
|
|
|
Variables:
|
|
|
|
```text
|
|
k = turbulent kinetic energy
|
|
ω = specific dissipation rate
|
|
```
|
|
|
|
Eddy viscosity:
|
|
|
|
```math
|
|
\nu_t=\frac{k}{\omega}
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
strong near-wall behavior; sensitive to free-stream ω
|
|
```
|
|
|
|
### SST k-omega — Menter Shear-Stress Transport
|
|
|
|
```text
|
|
K_OMEGA_SST_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
blends k-omega near wall with k-epsilon-like behavior away from wall; includes shear-stress limiter
|
|
```
|
|
|
|
Project role:
|
|
|
|
```text
|
|
industrial default candidate for adverse-pressure-gradient and separated aerodynamic flows
|
|
```
|
|
|
|
### Baseline k-omega / BSL
|
|
|
|
```text
|
|
K_OMEGA_BSL_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
blended k-omega/k-epsilon baseline without full SST limiter behavior
|
|
```
|
|
|
|
### k-kl-omega transition model
|
|
|
|
```text
|
|
K_KL_OMEGA_TRANSITION_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
three-equation transition-sensitive model using laminar kinetic energy plus k/omega variables
|
|
```
|
|
|
|
### k-tau / k-zeta / related two-equation variants
|
|
|
|
```text
|
|
K_TAU_VARIANT_GATE
|
|
K_ZETA_VARIANT_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
alternative time-scale or variable transformations of two-equation turbulence closures
|
|
```
|
|
|
|
## 7. Three-/four-equation and transition closures
|
|
|
|
### v2-f model
|
|
|
|
```text
|
|
V2_F_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
near-wall turbulence anisotropy and wall-normal velocity scale model, often four-equation
|
|
```
|
|
|
|
### ζ-f / zeta-f model
|
|
|
|
```text
|
|
ZETA_F_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
elliptic relaxation / wall-blocking inspired variant using velocity-scale ratio
|
|
```
|
|
|
|
### Intermittency / gamma-Re-theta transition model
|
|
|
|
```text
|
|
GAMMA_RE_THETA_TRANSITION_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
transition model with intermittency and transition momentum-thickness Reynolds number variables
|
|
```
|
|
|
|
### e^N / boundary-layer transition method
|
|
|
|
```text
|
|
E_N_TRANSITION_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
linear stability / amplification-factor transition prediction, often coupled to boundary-layer/RANS methods
|
|
```
|
|
|
|
### Langtry-Menter transition model
|
|
|
|
```text
|
|
LANGTRY_MENTER_TRANSITION_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
correlation-based transition model often used with SST
|
|
```
|
|
|
|
## 8. Reynolds Stress Transport Models
|
|
|
|
### RSM / RSTM — Reynolds Stress Model
|
|
|
|
```text
|
|
REYNOLDS_STRESS_MODEL_GATE
|
|
```
|
|
|
|
Purpose:
|
|
|
|
```text
|
|
solve transport equations for individual Reynolds stress tensor components plus scale equation
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
higher-physics RANS closure; avoids simple Boussinesq alignment assumption
|
|
```
|
|
|
|
Classic chart note:
|
|
|
|
```text
|
|
roughly 7 additional PDEs in common formulations
|
|
```
|
|
|
|
Scar risks:
|
|
|
|
```text
|
|
pressure-strain closure
|
|
wall reflection terms
|
|
numerical stiffness
|
|
boundary conditions
|
|
model constants
|
|
```
|
|
|
|
### LRR Reynolds stress model
|
|
|
|
```text
|
|
LRR_REYNOLDS_STRESS_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
Launder-Reece-Rodi style pressure-strain closure family
|
|
```
|
|
|
|
### SSG Reynolds stress model
|
|
|
|
```text
|
|
SSG_REYNOLDS_STRESS_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
Speziale-Sarkar-Gatski nonlinear pressure-strain closure family
|
|
```
|
|
|
|
### Elliptic blending Reynolds stress models
|
|
|
|
```text
|
|
ELLIPTIC_BLEND_RSM_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
near-wall anisotropy and wall-blocking behavior using elliptic blending/relaxation ideas
|
|
```
|
|
|
|
## 9. Nonlinear eddy-viscosity / algebraic stress models
|
|
|
|
### Nonlinear Eddy Viscosity Models
|
|
|
|
```text
|
|
NONLINEAR_EDDY_VISCOSITY_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
extend Boussinesq model with nonlinear strain/rotation tensor terms
|
|
```
|
|
|
|
### Explicit Algebraic Reynolds Stress Models — EARSM
|
|
|
|
```text
|
|
EARSM_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
approximate Reynolds stress anisotropy algebraically from strain/rotation invariants, often derived from RSM equilibrium assumptions
|
|
```
|
|
|
|
### Quadratic / cubic constitutive relation models
|
|
|
|
```text
|
|
QUADRATIC_CUBIC_STRESS_CLOSURE_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
higher-order tensor polynomial stress-strain closures
|
|
```
|
|
|
|
## 10. Compressible / high-speed turbulence additions
|
|
|
|
### Compressibility corrections
|
|
|
|
```text
|
|
COMPRESSIBILITY_CORRECTION_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
modify RANS/LES closures for dilatation, turbulent Mach number, shock interaction
|
|
```
|
|
|
|
### Shock-unsteadiness / shock-capturing scar gate
|
|
|
|
```text
|
|
SHOCK_TURBULENCE_INTERACTION_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
flag regions where shock/turbulence coupling makes closure assumptions fragile
|
|
```
|
|
|
|
### Morkovin-hypothesis guard
|
|
|
|
```text
|
|
MORKOVIN_GUARD_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
records whether compressible boundary layer assumptions are expected to be valid
|
|
```
|
|
|
|
## 11. Multiphase / reacting / MHD turbulence closures
|
|
|
|
These are not one universal closure; they are model families layered on top of turbulence closures.
|
|
|
|
### Scalar flux / turbulent Prandtl-Schmidt closures
|
|
|
|
```text
|
|
TURBULENT_PRANDTL_SCHMIDT_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
model turbulent transport of heat/species/scalars
|
|
```
|
|
|
|
### Combustion turbulence closures
|
|
|
|
```text
|
|
TURBULENCE_CHEMISTRY_INTERACTION_GATE
|
|
EDC_COMBUSTION_GATE
|
|
FLAMELET_TURBULENCE_GATE
|
|
PDF_COMBUSTION_TURBULENCE_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
model turbulence-chemistry interaction; separate Warden guard from pure flow closure
|
|
```
|
|
|
|
### Multiphase turbulence closures
|
|
|
|
```text
|
|
MULTIPHASE_TURBULENCE_GATE
|
|
TWO_FLUID_TURBULENCE_GATE
|
|
DISPERSED_PHASE_TURBULENCE_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
turbulence modulation by particles/bubbles/droplets and interphase coupling
|
|
```
|
|
|
|
### MHD turbulence closures
|
|
|
|
```text
|
|
MHD_TURBULENCE_GATE
|
|
ALFVENIC_TURBULENCE_WITNESS_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
magnetohydrodynamic turbulence; links to plasma chiral drag and Alfvén-wave witness channels
|
|
```
|
|
|
|
## 12. Reduced-order / data-driven turbulence models
|
|
|
|
These must be treated as model-augmentation gates, not automatic truth.
|
|
|
|
### POD / Galerkin reduced-order models
|
|
|
|
```text
|
|
POD_GALERKIN_ROM_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
low-dimensional basis for flow reconstruction/control
|
|
```
|
|
|
|
### DMD / Koopman models
|
|
|
|
```text
|
|
DMD_KOOPMAN_TURBULENCE_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
modal time-evolution and recurrence witness
|
|
```
|
|
|
|
### Neural turbulence closures
|
|
|
|
```text
|
|
NEURAL_TURBULENCE_CLOSURE_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
learn subgrid, RANS closure, correction, or wall model from data
|
|
```
|
|
|
|
Warden checks:
|
|
|
|
```text
|
|
training distribution
|
|
generalization regime
|
|
physical constraints
|
|
invariance
|
|
stability
|
|
uncertainty
|
|
out-of-distribution flags
|
|
```
|
|
|
|
### Symbolic-regression closures
|
|
|
|
```text
|
|
SYMBOLIC_REGRESSION_CLOSURE_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
learn explicit algebraic/tensor closure forms that can be inspected and receipted
|
|
```
|
|
|
|
### Bayesian / UQ turbulence model calibration
|
|
|
|
```text
|
|
BAYESIAN_TURBULENCE_CALIBRATION_GATE
|
|
UQ_TURBULENCE_MODEL_GATE
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
parameter uncertainty, model-form uncertainty, posterior closure calibration
|
|
```
|
|
|
|
## 13. Wall-treatment atlas
|
|
|
|
Wall models are often as important as the turbulence model itself.
|
|
|
|
```text
|
|
WALL_FUNCTION_GATE
|
|
ENHANCED_WALL_TREATMENT_GATE
|
|
LOW_RE_WALL_RESOLVED_GATE
|
|
TWO_LAYER_WALL_MODEL_GATE
|
|
EQUILIBRIUM_WALL_MODEL_GATE
|
|
NON_EQUILIBRIUM_WALL_MODEL_GATE
|
|
SLIP_WALL_MODEL_GATE
|
|
```
|
|
|
|
Warden checks:
|
|
|
|
```text
|
|
y+ range
|
|
wall shear target
|
|
separation / pressure gradient
|
|
roughness
|
|
heat transfer
|
|
wall curvature
|
|
mesh resolution
|
|
```
|
|
|
|
## 14. Project-specific witness closures
|
|
|
|
These are the project's additions on top of classical models.
|
|
|
|
### 16D FAMM witness closure
|
|
|
|
```text
|
|
FAMM_16D_WITNESS_CLOSURE_GATE
|
|
```
|
|
|
|
Purpose:
|
|
|
|
```text
|
|
augment classical turbulence model with 16D audit packet: geometry, torsion, chirality, semantic/witness mass, recurrence, delta memory, scars, residuals, invariant overlap, route cost, receipt strength
|
|
```
|
|
|
|
Role:
|
|
|
|
```text
|
|
not a replacement closure by itself; an audit/control layer for where a closure is safe or blind
|
|
```
|
|
|
|
### Shadow Control Gap Map
|
|
|
|
```text
|
|
SHADOW_CONTROL_GAP_TURBULENCE_GATE
|
|
```
|
|
|
|
Purpose:
|
|
|
|
```text
|
|
explicitly record where the witness packet does not control the dangerous term
|
|
```
|
|
|
|
3D danger term:
|
|
|
|
```math
|
|
(\omega\cdot\nabla)u
|
|
```
|
|
|
|
Gap shape:
|
|
|
|
```math
|
|
\mathcal S_{\mathrm{gap}}
|
|
=
|
|
\left[
|
|
\| (\omega\cdot\nabla)u\|_{\mathrm{unwitnessed}}
|
|
-
|
|
C\,\mathcal W_{16D}
|
|
\right]_+
|
|
```
|
|
|
|
### Photonic / Burgers residual witness
|
|
|
|
```text
|
|
PHOTONIC_BURGERS_RESIDUAL_WITNESS_GATE
|
|
```
|
|
|
|
Purpose:
|
|
|
|
```text
|
|
use fixed-point Burgers/triad solver plus external/stochastic witness channel as unresolved-mode indicator
|
|
```
|
|
|
|
### Plasma chiral drag / Alfvénic witness
|
|
|
|
```text
|
|
PLASMA_CHIRAL_DRAG_TURBULENCE_WITNESS_GATE
|
|
```
|
|
|
|
Purpose:
|
|
|
|
```text
|
|
use chiral/Alfvénic wave rotation as signed torsion/witness receipt in MHD-like regions
|
|
```
|
|
|
|
### OR-Tools regional model scheduler
|
|
|
|
```text
|
|
OR_TOOLS_TURBULENCE_REGION_SCHEDULER_GATE
|
|
```
|
|
|
|
Purpose:
|
|
|
|
```text
|
|
choose which turbulence model applies to which mesh region under budget and risk constraints
|
|
```
|
|
|
|
Decision variables:
|
|
|
|
```text
|
|
x_region_model = 1 if model m is selected for region r
|
|
```
|
|
|
|
Objective:
|
|
|
|
```text
|
|
minimize CPU cost + residual risk + scar pressure
|
|
maximize witness strength + invariant coverage
|
|
```
|
|
|
|
Constraints:
|
|
|
|
```text
|
|
budget ≤ B
|
|
wall regions must satisfy wall-treatment guard
|
|
high-gap regions cannot use algebraic-only closure
|
|
scarred closures blocked unless explicitly reopened
|
|
DNS/LES only where mesh/time budget supports them
|
|
```
|
|
|
|
## FAMM residual score for any turbulence model
|
|
|
|
```math
|
|
R_{\mathrm{model}}
|
|
=
|
|
\lambda_1 R_{\mathrm{closure}}
|
|
+
|
|
\lambda_2 R_{\mathrm{wall}}
|
|
+
|
|
\lambda_3 R_{\mathrm{grid}}
|
|
+
|
|
\lambda_4 R_{\mathrm{time}}
|
|
+
|
|
\lambda_5 R_{\mathrm{invariant}}
|
|
+
|
|
\lambda_6 \Omega_{\mathrm{scar}}
|
|
```
|
|
|
|
Promotion condition:
|
|
|
|
```math
|
|
R_{\mathrm{model}}\le\Theta_{\mathrm{region}}
|
|
```
|
|
|
|
## Suggested region routing
|
|
|
|
| Region / flow situation | Candidate model family | Warden caution |
|
|
|---|---|---|
|
|
| low-Re benchmark / small domain | DNS | cost explosion at high Re |
|
|
| separated unsteady flow | LES / DES / IDDES / SAS | grid and gray-area scars |
|
|
| attached aerodynamic boundary layer | SA / SST / algebraic if simple | adverse pressure gradient scars |
|
|
| industrial steady approximation | k-epsilon / SST / RSM | closure validity by regime |
|
|
| strong anisotropy / swirl / curvature | RSM / EARSM / nonlinear EVM | pressure-strain/model constants |
|
|
| near-wall heat transfer | low-Re / wall-resolved / enhanced wall | y+ and thermal wall functions |
|
|
| transition-sensitive flow | gamma-Re-theta / e^N / k-kl-omega | transition correlation domain |
|
|
| compressible/shock flow | compressible corrections + shock gate | shock/turbulence interaction scars |
|
|
| MHD/plasma-like flow | MHD turbulence + Alfvén witness | coupling assumptions |
|
|
| constrained compute browser/demo | algebraic / SA / reduced-order | never call it full physics |
|
|
|
|
## Stack placement
|
|
|
|
```text
|
|
TURBULENCE_MODEL_ATLAS_GATE
|
|
→ DNS / LES / RANS / hybrid / algebraic model candidates
|
|
→ 16D Shell Atlas / PathEpigenetic gate / Chaos Game shrinker
|
|
→ FAMM shadow-gap audit
|
|
→ OR-Tools regional scheduler
|
|
→ Anti-FAMM closure-blindness attack
|
|
→ NUVMAP route memory
|
|
→ Warden promote / scar / reopen
|
|
```
|
|
|
|
## Anti-FAMM checks
|
|
|
|
For every turbulence model, Anti-FAMM asks:
|
|
|
|
```text
|
|
What term did the closure hide?
|
|
Where does the model look stable while the dangerous physics escapes?
|
|
Which wall/mesh/time guard failed?
|
|
Is the model outside its calibration regime?
|
|
Did numerical dissipation masquerade as physics?
|
|
Did the residual move into an unobserved shadow channel?
|
|
```
|
|
|
|
## Best project sentence
|
|
|
|
The turbulence model atlas converts DNS, LES, DES, RANS, Reynolds-stress, k-epsilon, k-omega, Spalart-Allmaras, algebraic, transition, wall, compressible, multiphase, MHD, and data-driven closures into explicit witness gates. The Warden no longer asks only which model has more physics or less CPU cost; it asks which regional closure preserves the necessary invariants, exposes its unresolved residual, satisfies its wall/grid/validity guards, and carries enough 16D/FAMM witness strength to be promoted.
|
|
|
|
## References
|
|
|
|
```bibtex
|
|
@book{pope2000turbulent,
|
|
title = {Turbulent Flows},
|
|
author = {Pope, Stephen B.},
|
|
publisher = {Cambridge University Press},
|
|
year = {2000}
|
|
}
|
|
|
|
@book{wilcox2006turbulence,
|
|
title = {Turbulence Modeling for CFD},
|
|
author = {Wilcox, David C.},
|
|
publisher = {DCW Industries},
|
|
year = {2006}
|
|
}
|
|
|
|
@article{spalart1992one,
|
|
title = {A one-equation turbulence model for aerodynamic flows},
|
|
author = {Spalart, P. R. and Allmaras, S. R.},
|
|
journal = {AIAA Paper 92-0439},
|
|
year = {1992}
|
|
}
|
|
|
|
@article{menter1994two,
|
|
title = {Two-equation eddy-viscosity turbulence models for engineering applications},
|
|
author = {Menter, F. R.},
|
|
journal = {AIAA Journal},
|
|
volume = {32},
|
|
number = {8},
|
|
pages = {1598--1605},
|
|
year = {1994}
|
|
}
|
|
|
|
@article{smagorinsky1963general,
|
|
title = {General circulation experiments with the primitive equations},
|
|
author = {Smagorinsky, Joseph},
|
|
journal = {Monthly Weather Review},
|
|
volume = {91},
|
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number = {3},
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year = {1963}
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}
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|
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year = {1991}
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}
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@article{spalart1997comments,
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|
title = {Comments on the feasibility of LES for wings, and on a hybrid RANS/LES approach},
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|
author = {Spalart, P. R. and Jou, W.-H. and Strelets, M. and Allmaras, S. R.},
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journal = {Advances in DNS/LES},
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year = {1997}
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}
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@article{launder1975progress,
|
|
title = {Progress in the development of a Reynolds-stress turbulence closure},
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pages = {537--566},
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year = {1975}
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}
|
|
```
|