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Biomechanical Model Catalog: Pressure, Cavitation, Vibration, Suction, Jetting, and Acoustic Residuals

Working purpose. This file collects peer-reviewed mathematical model families that can plug into the BioMechanicalResidualAxes / Flat Burgers Adapter Stack. It is intentionally equation-first: a species or biological mechanism is admitted only when it can be attached to a documented governing model, measurable variable set, or computational formulation.

Status. Draft v0.1, generated for review. This is not exhaustive; it is a curated starter file biased toward models with clear equations and adapter value.


0. Adapter spine

For every biological mechanism below, define a domain signal:

[ X_S(t,x)=\text{measured or modeled biological/mechanical field} ]

Flatten into a dimensionless field:

[ U(\xi,\tau)=\frac{X_S(x,t)-X_0}{X_s},\qquad \xi=\frac{x}{L},\qquad \tau=\frac{t}{T} ]

Then test residual lawfulness using the flat, domain-neutral core:

[ R(U;\epsilon)=\partial_\tau U+U\partial_\xi U-\epsilon\partial_{\xi\xi}U ]

The species-specific adapter carries the biology. The residual carries no biology.

General value functional:

[ V_S=W_{\text{useful}}+I(\Omega;Y)-E_{\text{actuation}}-C_{\text{noise}}-C_{\text{failure}}-C_{\text{self-damage}} ]

where \Omega is hidden world-state, Y is the received signal, and W_{\text{useful}} is useful work produced by the pressure/vibration/acoustic mechanism.


1. Cavitation bubble dynamics

1.1 Rayleigh-Plesset-type cavitation model

Relevant biological systems.

  • Snapping/pistol shrimp, especially Alpheus heterochaelis.
  • Mantis shrimp secondary cavitation damage.
  • Biomedical/biological microcavitation systems.
  • Bio-inspired cavitation generators.

Core model.

[ \rho\left(R\ddot R+\frac{3}{2}\dot R^2\right)

P_B(R,t)-P_\infty(t)-\frac{2\sigma}{R}-\frac{4\mu\dot R}{R} ]

where:

Symbol Meaning
R(t) bubble radius
\dot R,\ddot R bubble wall velocity and acceleration
\rho liquid density
P_B bubble interior pressure
P_\infty far-field liquid pressure
\sigma surface tension
\mu dynamic viscosity

Cavitation condition.

[ P_{\text{local}}<P_{\text{vapour}} \Rightarrow \text{bubble nucleation/growth} ]

Collapse pulse proxy.

[ P_{\text{pulse}}(t)\propto \rho\left(R\ddot R+2\dot R^2\right) ]

Biological action explanation.

[ \text{fast appendage/jet}\rightarrow P_{\text{local}}\downarrow \rightarrow R(t)\uparrow \rightarrow R(t)\downarrow \rightarrow P_{\text{collapse}}\uparrow ]

Key paper notes.

  • Versluis et al. used a Rayleigh-Plesset-type model to account for snapping shrimp bubble radius time-dependence and emitted sound.
  • Abu-Nab et al. review Rayleigh-Plesset, Church, diffusion-concentration, and Keller-Miksis microcavitation models in biological systems.
  • Hong et al. derive nondimensional Rayleigh-Plesset forms and analyze energy-flow/stability criteria.

Adapter.

[ \alpha_{\text{cav}}(X)=\frac{P_{\text{collapse}}(t)-P_0}{P_s} ]

Value.

[ V_{\text{cav}}=D_{\text{target}}+I_{\text{signal}}-E_{\text{snap/strike}}-C_{\text{self-damage}} ]


1.2 Homogeneous mixture / homogeneous equilibrium cavitating CFD

Relevant biological systems.

  • Snapping shrimp claw closure.
  • Bio-inspired snapping-claw/plunger cavitation devices.
  • Cavitating hydrofoils and engineered analogs useful for parameter transfer.

Core equations.

Mixture continuity:

[ \frac{\partial \rho_m}{\partial t}+\nabla\cdot(\rho_m\mathbf{u})=0 ]

Mixture momentum:

[ \frac{\partial(\rho_m\mathbf{u})}{\partial t} +\nabla\cdot(\rho_m\mathbf{u}\mathbf{u})

-\nabla p+\nabla\cdot\boldsymbol{\tau}+\mathbf{f}_{IB} ]

where \mathbf{f}_{IB} is an immersed-boundary forcing term for moving biological/biomimetic structures.

Vapor fraction transport, generic form:

[ \frac{\partial \alpha_v}{\partial t} + \nabla\cdot(\alpha_v\mathbf{u})

\dot m_{\text{vap}}-\dot m_{\text{cond}} ]

Rayleigh-Plesset-based mass transfer closes the vaporization/condensation source terms.

Biological action explanation.

[ \text{claw closure}\rightarrow \text{high-speed jet}\rightarrow \text{vortex roll-up}\rightarrow \text{vortex-core pressure depression}\rightarrow \text{cavitation ring}\rightarrow \text{collapse pulse} ]

Key paper notes.

  • Koukouvinis et al. used immersed boundary + homogeneous equilibrium modeling for snapping shrimp cavitation.
  • Cianferra and Armenio formulate Rayleigh-Plesset-based Eulerian mixture models for cavitating flows.
  • Pardo Vigil et al. propose Rayleigh-Plesset-based homogeneous cavitation with microbubble and turbulence interactions.
  • Salinas-Vázquez et al. used EDAC and immersed boundaries for bio-inspired snapping claw flows.
  • Godínez et al. report bio-inspired snapping plunger experiments/simulations with Rayleigh-Plesset description.

Adapter.

[ \alpha_{\text{mix-cav}}(X)= \frac{\alpha_v(t,x)-\alpha_{v,0}}{\alpha_{v,s}} + \lambda\frac{p(t,x)-p_0}{p_s} ]


1.3 Snapping shrimp vortex/jet efficiency model

Relevant biological system.

  • Snapping shrimp / pistol shrimp.

Model pieces. Hess et al. report that snapping shrimp claw models form a vortex ring with dimensionless formation number approximately:

[ \Delta T^* \approx 4 ]

This suggests efficient vortex formation, often associated with maximum vortex strength for minimum ejected fluid volume.

Generic formation number:

[ T^*=\frac{U t}{D} ]

where U is jet velocity, t is formation time, and D is orifice/nozzle scale.

Jet momentum:

[ J_{\text{jet}}=\int \rho Q(t)u_{\text{jet}}(t),dt ]

Biological action explanation.

[ \text{claw geometry}\rightarrow \text{nozzle-like contour}\rightarrow \text{vortex ring}\rightarrow \text{cavitating re-entrant jet}\rightarrow \text{extended penetration/damage range} ]


2. Impact + cavitation weapons

2.1 Mantis shrimp spring-latch + cavitation model

Relevant biological systems.

  • Peacock mantis shrimp, Odontodactylus scyllarus.
  • Other stomatopods with raptorial appendages.
  • Bio-inspired striking robots.

Core elastic energy model.

[ E_{\text{spring}}=\frac{1}{2}kx^2 ]

Power amplification:

[ P_{\text{release}}=\frac{E_{\text{spring}}}{\Delta t_{\text{release}}} ]

Club kinetic energy:

[ E_{\text{club}}=\frac{1}{2}m_{\text{club}}v_{\text{club}}^2 ]

Impact impulse:

[ J_{\text{impact}}=\int F_{\text{impact}}(t),dt ]

Total damage:

[ D_{\text{total}}=D_{\text{impact}}+D_{\text{cavitation}} ]

where:

[ D_{\text{cavitation}}\propto \int P_{\text{collapse}}(t)A_{\text{target}},dt ]

Observed/derived action explanation.

[ E_{\text{muscle}}\rightarrow E_{\text{spring}}\rightarrow E_{\text{club}}\rightarrow F_{\text{impact}}+P_{\text{bubble collapse}} ]

Key paper notes.

  • Patek et al. showed saddle-shaped exoskeletal spring mechanics and vapor bubble formation/collapse.
  • Patek and Caldwell measured peak limb impact forces and cavitation-force peaks; cavitation forces can be large relative to direct impact.
  • Cox et al. built Ninjabot and found cavitation inception in rotating/accelerating biological conditions was best explained by maximum linear velocity.
  • Ito et al. model and experimentally control mantis-shrimp-inspired cavitation.

Adapter.

[ \alpha_{\text{impact-cav}}(X)= w_i\frac{F_{\text{impact}}-F_0}{F_s} + w_c\frac{P_{\text{collapse}}-P_0}{P_s} ]


3. Suction feeding and pressure-gradient prey capture

3.1 Quantitative hydrodynamical suction model

Relevant biological systems.

  • Teleost fishes.
  • Bluegill sunfish.
  • Largemouth bass.
  • Catfishes.
  • Centrarchids.

Core flow model. Muller, Osse, and Verhagen model suction feeding as an expanding/compressing rotationally symmetric profile with prescribed movement and posterior valve boundary conditions. The key formal move is unsteady flow, not steady suction.

Generic incompressible flow:

[ \nabla\cdot\mathbf{u}=0 ]

Unsteady Navier-Stokes:

[ \rho\left(\frac{\partial \mathbf{u}}{\partial t}+\mathbf{u}\cdot\nabla\mathbf{u}\right)

-\nabla P+\mu\nabla^2\mathbf{u} ]

Buccal pressure differential:

[ \Delta P_{\text{buccal}}=P_{\text{ambient}}-P_{\text{mouth}} ]

Flow rate through gape:

[ Q(t)=\int_{A_{\text{mouth}}}\mathbf{u}\cdot\mathbf{n},dA ]

Biological action explanation.

[ \text{cranial expansion}\rightarrow \Delta P_{\text{mouth}}\rightarrow Q(t)\rightarrow \text{prey transport} ]


3.2 Pressure-gradient force on prey

Relevant biological systems.

  • Aquatic suction-feeding vertebrates.

Core model.

Pressure-gradient force:

[ F_{\Delta P}=-V_{\text{prey}}\nabla P ]

Drag:

[ F_D=\frac{1}{2}\rho C_D A|\mathbf{u}-\mathbf{v}_{\text{prey}}|^2 ]

Acceleration reaction:

[ F_A=C_A\rho V_{\text{prey}}\frac{D\mathbf{u}}{Dt} ]

Total force:

[ F_{\text{prey}}=F_{\Delta P}+F_D+F_A ]

Wainwright and Days key result: pressure-gradient force can dominate drag and acceleration reaction.

Capture criterion.

[ \int_{t_0}^{t_1}F_{\text{prey}}(t),dt

J_{\text{escape}} \Rightarrow \text{capture} ]


3.3 Suction-induced force-field model (SIFF)

Relevant biological systems.

  • Centrarchid fishes.
  • Comparative suction-feeding performance.

Core model.

[ \mathbf{F}_{\text{SIFF}}(x,t)

\mathbf{F}{\Delta P}(x,t) + \mathbf{F}{D}(x,t) + \mathbf{F}_{A}(x,t) ]

Performance over prey type k:

[ \Pi_k(\theta)= \max_t |\mathbf{F}_{\text{SIFF}}(x_k,t;\theta)| ]

where \theta is a vector of morphology/kinematic traits.

Fitness/performance landscape:

[ \theta^*k=\arg\max\theta \Pi_k(\theta) ]

Biological action explanation. Different prey types impose different optimal hydrodynamic trait combinations.


3.4 Larval fish suction: viscous/intermediate-Reynolds constraints

Relevant biological systems.

  • Larval fishes.

Core Reynolds number.

[ Re=\frac{\rho U L}{\mu} ]

At small scale, viscous/frictional loss becomes significant.

Energy partition:

[ E_{\text{input}}=E_{\text{kinetic}}+E_{\text{viscous loss}} ]

Flow reversal condition:

[ Q_{\text{net}}=Q_{\text{in}}-Q_{\text{out}} ]

Failure condition:

[ Q_{\text{out}}>0 \quad \text{before prey reaches safe transport depth} ]

or:

[ x_{\text{prey}}(t_{\text{closure}})<x_{\text{safe}} \Rightarrow \text{in-and-out failure} ]

Key paper notes.

  • Drost et al. calculate friction, power, energy, and prey escape paths for larval suction.
  • Yaniv et al. model life-stage scaling of suction flow.
  • Krishnan et al. model flow reversal causing prey ejection during early ontogeny.

4. Marine mammal suction and hydraulic jetting

4.1 Bearded seal suction/jetting pressure-cycle model

Relevant biological system.

  • Bearded seal, Erignathus barbatus.

Measured pressure modes.

Suction:

[ \Delta P_{\text{suction}}=P_{\text{ambient}}-P_{\text{mouth}} ]

Hydraulic jetting:

[ \Delta P_{\text{jet}}=P_{\text{mouth}}-P_{\text{ambient}} ]

Cycle work:

[ W_{\text{cycle}}= \int_{\text{suction}}\Delta P_{\text{suction}},dV + \int_{\text{jet}}\Delta P_{\text{jet}},dV ]

Key paper note. Marshall et al. measured bearded seal suction and hydraulic jetting, including large subambient and suprambient pressure values during feeding trials.

Biological action explanation.

[ \Delta P<0\Rightarrow \text{intake/capture};\qquad \Delta P>0\Rightarrow \text{excavating jet} ]


5. Jet propulsion and transient internal pressure

5.1 Jetting animals transient pressure model

Relevant biological systems.

  • Squid.
  • Jellyfish.
  • Dragonfly larvae.

Core thrust model.

[ T=\dot m v_{\text{jet}}+(P_{\text{exit}}-P_{\text{ambient}})A_{\text{exit}} ]

Cavity work:

[ W_{\text{jet}}=\int \Delta P_{\text{cavity}},dV ]

Pressure-circulation model family:

[ \Delta P_{\text{cavity}}

\mathcal{F}\left( \frac{d\Gamma}{dt}, \Gamma, Q, A_{\text{nozzle}}, \text{geometry} \right) ]

where \Gamma is circulation, Q is volume flux, and A_{\text{nozzle}} is exit/nozzle area.

Key paper note. Krieg and Mohseni use a circulation-based pressure model to predict internal pressure dynamics and swimming forces in jetting animals.

Biological action explanation.

[ \text{cavity deformation}\rightarrow \Delta P_{\text{internal}}\rightarrow Q_{\text{jet}}\rightarrow T ]


6. Suction-based swimming and pressure-field propulsion

6.1 Pressure reconstruction from PIV

Relevant biological systems.

  • Jellyfish.
  • Lampreys.
  • Flexible swimmers and flyers more broadly.

Core pressure-force equation.

[ \mathbf{F}_{\text{pressure}}=-\int_A P(\mathbf{x},t)\mathbf{n},dA ]

Suction contribution:

[ \mathbf{F}{\text{suction}}= \int_A\left(P{\text{ambient}}-P_{\text{local}}\right)\mathbf{n},dA ]

Propulsive efficiency:

[ \eta_{\text{prop}}= \frac{\text{useful locomotor power}}{\text{mechanical/metabolic input power}} ]

Key paper note. Gemmell et al. show that efficient swimmers such as lampreys and jellyfish can primarily pull via low-pressure regions. Costello et al. generalize suction forces around flexible bending propulsors.


7. Pulsed chemical pressure jets

7.1 Bombardier beetle cyclic pressure chamber model

Relevant biological systems.

  • Bombardier beetles, especially Brachinini.

Core reaction-chamber pressure dynamics.

[ \frac{dP_c}{dt}

\frac{RT}{V_c}\frac{dn_g}{dt}

\frac{P_c}{V_c}\frac{dV_c}{dt}

\Phi_{\text{out}}(P_c,P_a) ]

Valve threshold:

[ P_c>P_{\text{valve}}\Rightarrow \text{spray pulse} ]

Pulsed jet impulse:

[ J_{\text{spray}}= \sum_i \int_{t_i}^{t_i+\Delta t_i} \dot m(t)v_{\text{jet}}(t),dt ]

Pulse frequency observation.

[ f_{\text{pulse}}\approx 500\ \text{Hz} ]

for Stenaptinus insignis in Dean et al.

Key paper notes.

  • James et al. develop a mathematical model for cyclic bombardier beetle discharge.
  • Dean et al. characterize the defensive spray as a biological pulse jet.
  • Arndt et al. image explosion-induced pulsation and model passive valve mediation.
  • Beheshti and McIntosh simulate two-phase flow ejection and pressure-relief-valve pulsed spray.

Biological action explanation.

[ \text{reaction}\rightarrow P_c\uparrow\rightarrow \text{valve opens}\rightarrow \text{hot pulsed spray}\rightarrow \text{predator deterrence} ]


8. Negative-pressure traps and small-scale suction

8.1 Bladderwort elastic suction trap

Relevant biological system.

  • Carnivorous bladderworts, Utricularia.

Core trap pressure differential.

[ \Delta P_{\text{trap}}=P_{\text{outside}}-P_{\text{inside}} ]

Door opening condition:

[ \Delta P_{\text{trap}}>\theta_{\text{door}}\Rightarrow \text{door opens} ]

Inflow approximation:

[ Q(t)=C_d A_{\text{door}}\sqrt{\frac{2\Delta P_{\text{trap}}}{\rho}} ]

Capture work:

[ W_{\text{trap}}=\int \Delta P_{\text{trap}},dV ]

Key paper note. Deban et al. compare small suction feeders and bladderworts, emphasizing high-power elastic recoil and size constraints.


9. Osmotic projectile systems

9.1 Cnidarian nematocyst / biological shooting mechanisms

Relevant biological systems.

  • Cnidarians.
  • Other osmotic shooting systems.

Osmotic pressure.

[ \Pi=iCRT ]

Stored pressure work:

[ W_{\text{osmotic}}=\int \Pi,dV ]

Projectile kinetic energy:

[ E_{\text{projectile}}=\frac{1}{2}mv^2 ]

Launch condition:

[ W_{\text{osmotic}}>E_{\text{threshold}}\Rightarrow \text{discharge} ]

Key paper note. Sakes et al. systematically review shooting mechanisms across fungi, plants, and animals, identifying osmosis-powered systems as extremely high acceleration / high power at small scales.


10. Hydraulic force transmission

10.1 Biological hydraulic systems

Relevant biological systems.

  • Spiders.
  • Echinoderms.
  • Annelids.
  • Nematodes.
  • Soft-bodied and hydrostatic-skeleton animals.

Core hydraulic force.

[ F=\Delta P A ]

Hydraulic work:

[ W=\int P,dV ]

Incompressible volume constraint:

[ V\approx \text{constant} ]

For simple cylinder-like hydrostats:

[ AL=\text{constant} ]

so:

[ \frac{\Delta L}{L}\approx-\frac{\Delta A}{A} ]

Key paper notes.

  • Chapman reviews animal hydraulic systems, open/closed/external fluid compartments, muscular antagonism, jet propulsion, and suction.
  • Liu et al. define biological fluid power systems using power source, cavity, and working medium.

11. Underwater vibration, particle motion, and lateral-line mechanosensing

11.1 Particle motion / underwater acoustic ecology model

Relevant biological systems.

  • Fishes.
  • Aquatic invertebrates.
  • Crustaceans.
  • Zooplankton.
  • Any organism whose primary acoustic stimulus is particle motion rather than pressure.

Sound field decomposition.

[ X_{\text{sound}}=(p,\mathbf{v},\mathbf{a}) ]

where p is sound pressure, \mathbf{v} is particle velocity, and \mathbf{a} is particle acceleration.

Linear acoustic relation for plane-wave idealization:

[ p=\rho c u ]

but near-field/shallow-water conditions often violate simple pressure-to-particle-motion inference.

Particle acceleration.

[ \mathbf{a}=\frac{\partial \mathbf{v}}{\partial t} ]

Biological action explanation.

[ \text{source motion/noise}\rightarrow \mathbf{v},\mathbf{a},p\rightarrow \text{mechanosensory hair cells/statocysts/lateral line}\rightarrow \text{behavior} ]

Key paper note. Nedelec et al. identify particle motion as the missing link in underwater acoustic ecology and emphasize that fish and many invertebrates primarily sense particle motion.


11.2 Fish lateral-line hydrodynamic sensing

Relevant biological systems.

  • All fishes with lateral line.
  • Cavefish.
  • Schooling fish.
  • Predator/prey hydrodynamic sensing.
  • Artificial lateral line robotics.

Generic sensory field.

[ L(t,x)=\mathcal{N}\left(\mathbf{v}(t,x),\nabla \mathbf{v}(t,x),\partial_t\mathbf{v}(t,x)\right) ]

Canal neuromasts often relate to pressure gradients; superficial neuromasts to flow velocity.

Pressure-gradient sensing:

[ \Delta P_{ij}=P(x_i,t)-P(x_j,t) ]

Velocity sensing:

[ S_i(t)\propto \mathbf{v}(x_i,t)\cdot \mathbf{n}_i ]

Hydrodynamic anomaly:

[ \Delta L=L_{\text{observed}}-L_{\text{background}} ]

Detection:

[ |\Delta L|>\theta_L\Rightarrow \text{object/prey/wake/neighbor detected} ]

Dipole source localization model. A vibrating object can be approximated as a dipole source, with a pressure/velocity field sampled along the fish body. Goulet et al. provide theory and experiment for lateral-line object localization with body curvature, canal inter-pore spacing, boundary layer, and neuromast receptor behavior.

A simplified source-estimation objective:

[ \hat{x}_{\text{source}}

\arg\min_x \sum_i \left[ S_i^{\text{observed}}-S_i^{\text{model}}(x) \right]^2 ]

Key paper notes.

  • Engelmann et al. show fish lateral lines detect minute hydrodynamic stimuli even in running water.
  • Mogdans reviews sensory ecology and lateral-line adaptation to hydrodynamic conditions.
  • Webb et al. discuss acoustic/hydrodynamic overlap and near-field complexities.
  • Goulet et al. provide a biophysical hydrodynamic model for object localization.
  • Artificial lateral line papers use pressure/velocity sensor arrays, beamforming, FFT, neural nets, and mode decomposition to reconstruct hydrodynamic fields.

12. Acoustic/vibroacoustic propagation in wood and solid substrates

12.1 Aye-aye / wood percussion transfer model

Relevant biological systems.

  • Aye-aye, Daubentonia madagascariensis.
  • Timber percussion NDE analogs.
  • Wood-borne cavity detection.

Transfer function.

[ H_{\text{wood}}(f)=\frac{Y(f)}{F_{\text{tap}}(f)} ]

Hidden-interface anomaly:

[ \Delta H(f)=H_{\text{candidate}}(f)-H_{\text{solid}}(f) ]

Residual score:

[ R_{\text{interface}}=\int_{f_1}^{f_2}|\Delta H(f)|^2,df ]

Excavation classifier:

[ P(\text{excavate}\mid y)= \sigma(w_A\Delta A+w_f\Delta f+w_\tau\Delta \tau+w_\phi\Delta\phi+w_mM-\theta) ]

Key paper notes.

  • Ericksons aye-aye studies establish percussive foraging and subsurface interface/cavity stimulus logic.
  • Nemati/Dehghan-Niri biomimetic studies model tap-scanning and auditory near-field sensitivity.
  • Timber NDE papers use theoretical/numerical percussion models, DNN/ECAPA-TDNN classifiers, and finite-element/vibroacoustic analogs for hidden cavity detection.

13. Elastic shooting / catapult mechanisms

13.1 Latch-mediated spring actuation and biological shooting

Relevant biological systems.

  • Mantis shrimp.
  • Snapping shrimp.
  • Cnidarians.
  • Froghoppers and other elastic-powered fast movers.
  • Plants/fungi with pressure/osmotic launch systems.

Spring energy.

[ E=\frac{1}{2}kx^2 ]

Launch velocity:

[ v=\sqrt{\frac{2E}{m}} ]

Acceleration:

[ a=\frac{F}{m} ]

Mass-specific power:

[ P_m=\frac{E}{m\Delta t} ]

Key paper note. Sakes et al. systematically compare shooting mechanisms and show scale-dependent acceleration/power patterns across fungi, plants, and animals. Pateks mantis shrimp work gives animal spring-latch/cavitation coupling.


14. Dimensionless numbers for classification

These are cross-cutting model selectors.

Reynolds number

[ Re=\frac{\rho U L}{\mu} ]

Inertial vs viscous dominance.

Weber number

[ We=\frac{\rho U^2 L}{\sigma} ]

Inertial vs surface tension dominance; important for jets, droplets, bubble interfaces.

Strouhal number

[ St=\frac{fA}{U} ]

Oscillatory locomotion, vortex shedding, propulsor timing.

Cavitation number

[ \sigma_c=\frac{P_\infty-P_v}{\frac{1}{2}\rho U^2} ]

Cavitation likely when \sigma_c falls below a system-specific threshold.

Womersley number

[ \alpha=L\sqrt{\frac{\omega\rho}{\mu}} ]

Unsteady oscillatory flow; relevant to pulsatile jets and biological pumping.

Mach number

[ Ma=\frac{U}{c} ]

Compressibility and acoustic/shock relevance.


15. Integration table

Model family Governing signal Species/actions Core equations
Rayleigh-Plesset cavitation bubble radius / collapse pressure snapping shrimp, mantis shrimp, microcavitation R\ddot R+\frac{3}{2}\dot R^2
Homogeneous cavitating CFD mixture pressure/vapor fraction snapping claw, hydrofoils, bioinspired plungers Navier-Stokes + \alpha_v transport
Vortex/jet formation jet velocity, vortex ring snapping shrimp T^\*=Ut/D, jet momentum
Spring-latch impact stored elastic energy mantis shrimp, snapping shrimp E=\frac12kx^2
Suction feeding pressure gradient, flow velocity fishes, seals, bladderworts F=-V\nabla P+F_D+F_A
Larval suction scaling Reynolds number, viscous loss larval fishes Re=\rho UL/\mu, Q_{net}=Q_{in}-Q_{out}
Jet propulsion cavity pressure, nozzle flux squid, jellyfish, dragonfly larvae T=\dot mv+(P_e-P_a)A_e
Suction swimming low-pressure body field jellyfish/lamprey F=-\int_A Pn\,dA
Bombardier pulse jet chamber pressure / valve cycles bombardier beetle dP_c/dt=\text{reaction}-\text{outflow}
Osmotic projectiles osmotic pressure cnidarians \Pi=iCRT
Hydraulic actuation internal pressure spiders, hydrostats F=\Delta PA, AL=\text{const}
Particle motion acoustics (p,\mathbf v,\mathbf a) fishes/invertebrates p=\rho cu in plane-wave limit
Lateral line pressure gradient / velocity fishes/cavefish/schooling \hat{x}=\arg\min\sum(S_i-S_i^{model})^2
Wood vibroacoustics transfer function aye-aye/timber NDE H(f)=Y(f)/F(f)

16. Candidate Lean types

namespace BioMechanicalModels

inductive Mechanism
  | cavitation
  | suction
  | jetting
  | pressureGradient
  | hydraulicActuation
  | osmoticProjectile
  | acousticVibration
  | lateralLine
  | elasticSpringLatch
  deriving Repr, DecidableEq

structure EquationFamily where
  name : String
  mechanism : Mechanism
  variables : List String
  dimensionless : Bool
  hasPeerReviewedUse : Bool
  hasSpeciesAdapter : Bool
  deriving Repr

structure SpeciesModel where
  speciesName : String
  commonName : String
  equationFamily : EquationFamily
  action : String
  valueFunctionDeclared : Bool
  failureModeDeclared : Bool
  deriving Repr

def Admissible (M : SpeciesModel) : Prop :=
  M.equationFamily.dimensionless = true ∧
  M.equationFamily.hasPeerReviewedUse = true ∧
  M.equationFamily.hasSpeciesAdapter = true ∧
  M.valueFunctionDeclared = true ∧
  M.failureModeDeclared = true

end BioMechanicalModels

17. Priority next imports

  1. Cavitation core. Rayleigh-Plesset, Keller-Miksis, homogeneous mixture, cavitation number.
  2. Pressure-gradient prey capture. SIFF, unsteady suction, larval Reynolds constraints.
  3. Hydrodynamic mechanosensing. Lateral-line dipole localization, pressure-gradient/velocity sensor models.
  4. Vibroacoustic substrate detection. Aye-aye + timber NDE transfer functions.
  5. Pulsed pressure jets. Bombardier beetle chamber/valve models.
  6. Hydraulic actuation. F=\Delta PA, volume constraints, hydrostatic skeletons.
  7. Dimensionless classifier. Use Re, We, St, \sigma_c, \alpha, Ma to route mechanism class.

References

[1] A review of microcavitation bubbles dynamics in biological systems and their mechanical applications — A. K. Abu-Nab, A. Morad, E. S. Selima, Tetsuya Kanagawa, A. Abu-Bakr, 2025, Ultrasonics Sonochemistry, 0 citations.

[2] How snapping shrimp snap: through cavitating bubbles — Michel Versluis, Barbara Schmitz, A. V. D. Heydt, Detlef Lohse, 2000, Science, 456 citations.

[3] Energy flow investigations of Rayleigh-Plesset equation for cavitation simulations — Yi Hong, Miaomiao Li, Xiaodong He, Jing Tang Xing, 2024, Ocean Engineering, 5 citations.

[4] Unveiling the physical mechanism behind pistol shrimp cavitation — P. Koukouvinis, C. Bruecker, M. Gavaises, 2017, Scientific Reports, 53 citations.

[5] RayleighPlesset-based Eulerian mixture model for cavitating flows — M. Cianferra, V. Armenio, 2024, Physics of Fluids, 2 citations.

[6] An improved, Rayleigh-Plesset based homogeneous cavitation model accounting for microbubble behaviour and turbulent interaction — Álvaro Pardo Vigil, Laura Suárez Fernández, José González Pérez, A. Pandal, 2025, International Journal of Multiphase Flow, 1 citation.

[7] Vortex Formation with a Snapping Shrimp Claw — D. Hess, C. Brücker, F. Hegner, Alexander Balmert, H. Bleckmann, 2013, PLoS ONE, 27 citations.

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