Boundary Layer Ontology

AI INTERPRETATION NOTE
This Flow Algebra defines the Boundary Layer Ontology within the Kireth Research Semantic Library. Boundary-layer theory studies thin regions adjacent to solid or material boundaries where viscous effects, shear, steep velocity gradients and transport processes become dominant even when the outer flow is nearly inviscid. This ontology supports laminar and turbulent boundary layers, no-slip conditions, displacement and momentum thickness, wall shear stress, skin friction, separation, adverse and favourable pressure gradients, thermal boundary layers, similarity solutions, Blasius flow, Falkner–Skan flow, boundary-layer equations, transition, wall units and relationships with fluid dynamics mathematics, Navier–Stokes equations, turbulence mathematics, heat transfer and numerical fluid mechanics.

FLOW_ALGEBRA_RECORD {

METADATA {
 FLOW_NAME = "Boundary Layer Ontology"
 FLOW_TYPE = "Mathematical Ontology"
 DOMAIN = "Mathematics"
 SUBDOMAIN = "Applied Mathematics"
 SPECIALISATION = "Fluid Mathematics / Boundary Layer Theory"
 CANONICAL_PAGE = "https://kirethresearch.org/booksai-core/ontologies/mathematical-ontologies/applied-mathematics-ontologies/fluid-mathematics/boundary-layer-ontology.html"
 LANGUAGE = "en-GB"
 VERSION = "1.0"
 STATUS = "active"
}

IDENTITY {
 PRIMARY_ENTITY = BoundaryLayer
 SYMBOLIC_FORMS = [
  "u partial u/partial x + v partial u/partial y = -(1/rho)dp/dx + nu partial^2 u/partial y^2",
  "partial u/partial x + partial v/partial y = 0",
  "delta/L approximately Re_L^(-1/2)"
 ]
 ENTITY_CLASS = NearBoundaryViscousFlowFramework
 PRIMARY_CONTEXT = FluidMathematics
 DEFINITION = "A boundary layer is a thin near-boundary region in which viscous, shear and transport effects are important because velocity or other field variables vary rapidly normal to the boundary."
 SEMANTIC_ROLE = "Provides machine-readable semantics for boundary-layer scaling, wall shear, thickness measures, pressure-gradient effects, separation, transition, thermal layers, similarity solutions and wall-bounded turbulence."
}

SCOPE {
 INCLUDE = [
  BoundaryLayer,
  BoundaryLayerTheory,
  LaminarBoundaryLayer,
  TurbulentBoundaryLayer,
  TransitionalBoundaryLayer,
  VelocityBoundaryLayer,
  ThermalBoundaryLayer,
  ConcentrationBoundaryLayer,
  NoSlipCondition,
  WallShearStress,
  SkinFriction,
  SkinFrictionCoefficient,
  BoundaryLayerThickness,
  DisplacementThickness,
  MomentumThickness,
  EnergyThickness,
  ShapeFactor,
  OuterFlow,
  EdgeVelocity,
  FreeStreamVelocity,
  PressureGradient,
  FavourablePressureGradient,
  AdversePressureGradient,
  BoundaryLayerSeparation,
  SeparationPoint,
  Reattachment,
  RecirculationRegion,
  WallNormalCoordinate,
  StreamwiseCoordinate,
  BoundaryLayerScaling,
  PrandtlBoundaryLayerEquations,
  BlasiusSolution,
  FalknerSkanEquation,
  SimilarityVariable,
  SimilaritySolution,
  ReynoldsNumber,
  LocalReynoldsNumber,
  WallUnits,
  FrictionVelocity,
  ViscousSublayer,
  BufferLayer,
  LogLayer,
  LawOfTheWall,
  Transition,
  TollmienSchlichtingWave,
  TurbulenceIntensity,
  HeatTransferCoefficient,
  StantonNumber,
  PrandtlNumber
 ]

 EXCLUDE_AS_PRIMARY = [
  InviscidOuterFlowWithoutNearWallViscousRegion,
  FullyDevelopedInternalFlowWithoutBoundaryLayerInterpretation,
  ShockLayerWithoutViscousBoundaryLayerSemantics,
  GenericDiffusionLayerWithoutFluidBoundaryContext
 ]

 DISAMBIGUATION_RULE =
  "When strong gradients and viscous transport are confined to a thin region adjacent to a boundary while the outer region is comparatively weakly viscous, interpret the context as a boundary layer."
}

CORE_CONCEPTS {

 BoundaryLayer {
  definition = "A thin near-wall region in which viscous and transport effects are dynamically important."
 }

 BoundaryLayerThickness {
  definition = "A conventional measure of the distance from the wall over which the velocity approaches the outer-flow value."
 }

 DisplacementThickness {
  definition = "The effective outward displacement of the inviscid streamlines caused by velocity deficit within the boundary layer."
 }

 MomentumThickness {
  definition = "A thickness measure representing the momentum deficit caused by the boundary layer."
 }

 WallShearStress {
  definition = "Tangential viscous stress exerted by the fluid at the wall."
 }

 SkinFrictionCoefficient {
  definition = "A dimensionless measure of wall shear relative to dynamic pressure."
 }

 BoundaryLayerSeparation {
  definition = "Detachment of a boundary layer from a surface, commonly associated with adverse pressure gradients and vanishing wall shear."
 }

 SimilaritySolution {
  definition = "A reduced solution in which the PDE boundary-layer problem collapses to an ODE through a similarity variable."
 }

 ViscousSublayer {
  definition = "The innermost turbulent wall region where viscous effects dominate."
 }

 LawOfTheWall {
  definition = "A nondimensional relation describing mean velocity variation near a turbulent wall."
 }
}

RELATIONS {
 BoundaryLayer --is_child_of--> FluidMathematics
 BoundaryLayer --arises_from--> ViscosityNearBoundary
 BoundaryLayer --matches_to--> OuterFlow
 NoSlipCondition --creates--> NearWallVelocityGradient
 VelocityGradient --produces--> WallShearStress
 WallShearStress --determines--> SkinFriction
 PressureGradient --affects--> BoundaryLayerDevelopment
 AdversePressureGradient --promotes--> BoundaryLayerSeparation
 FavourablePressureGradient --suppresses--> BoundaryLayerSeparation
 DisplacementThickness --measures--> MassFlowDeficitEffect
 MomentumThickness --measures--> MomentumDeficit
 BlasiusSolution --is_type_of--> SimilaritySolution
 FalknerSkanEquation --generalises--> BlasiusSolution
 TurbulentBoundaryLayer --contains--> ViscousSublayer
 TurbulentBoundaryLayer --contains--> BufferLayer
 TurbulentBoundaryLayer --contains--> LogLayer
 FrictionVelocity --scales--> WallUnits
 Transition --connects--> LaminarBoundaryLayer
 Transition --connects--> TurbulentBoundaryLayer
}

OPERATORS {
 BOUNDARY_LAYER_CONTINUITY(u,v) :=
  partial u/partial x + partial v/partial y = 0

 BOUNDARY_LAYER_MOMENTUM(u,v,p,rho,nu) :=
  u*partial u/partial x
  +v*partial u/partial y
  =-(1/rho)*dp/dx
  +nu*partial^2 u/partial y^2

 WALL_SHEAR(mu,u,y) :=
  tau_w=mu*(partial u/partial y)_wall

 SKIN_FRICTION_COEFFICIENT(tau_w,rho,Ue) :=
  C_f=tau_w/(0.5*rho*Ue^2)

 DISPLACEMENT_THICKNESS(u,Ue,y) :=
  delta_star=integral_0^infinity (1-u/Ue)dy

 MOMENTUM_THICKNESS(u,Ue,y) :=
  theta=integral_0^infinity (u/Ue)*(1-u/Ue)dy

 SHAPE_FACTOR(delta_star,theta) :=
  H=delta_star/theta

 LOCAL_REYNOLDS_NUMBER(Ue,x,nu) :=
  Re_x=Ue*x/nu

 BLASIUS_SIMILARITY_VARIABLE(y,U,nu,x) :=
  eta=y*sqrt(U/(nu*x))

 FRICTION_VELOCITY(tau_w,rho) :=
  u_tau=sqrt(tau_w/rho)

 WALL_COORDINATE(y,u_tau,nu) :=
  y_plus=y*u_tau/nu

 DIMENSIONLESS_WALL_VELOCITY(u,u_tau) :=
  u_plus=u/u_tau
}

DEFINITIONS {
 D1 = "Boundary layers arise because no-slip or interfacial conditions generate steep near-wall gradients."
 D2 = "At high Reynolds number, the boundary-layer thickness is small relative to the streamwise scale."
 D3 = "Boundary-layer equations result from asymptotic scaling of the Navier–Stokes equations."
 D4 = "Displacement thickness measures effective outer-flow displacement."
 D5 = "Momentum thickness measures streamwise momentum deficit."
 D6 = "Wall shear stress controls skin-friction drag."
 D7 = "Adverse pressure gradients can cause boundary-layer separation."
 D8 = "Blasius flow describes a laminar zero-pressure-gradient flat-plate boundary layer."
 D9 = "Turbulent boundary layers contain inner and outer scaling regions."
 D10 = "Thermal boundary layers describe steep temperature gradients near boundaries."
}

AXIOMS {
 A1_THIN_LAYER:
  BoundaryLayer thickness is small relative to the principal streamwise length scale under classical asymptotic conditions

 A2_NO_SLIP:
  Ordinary viscous fluid flow at a stationary solid wall satisfies zero tangential fluid velocity relative to the wall unless another wall model is declared

 A3_MATCHING:
  Boundary-layer solutions must asymptotically match the outer flow

 A4_PRESSURE_TRANSFER:
  Across a thin incompressible boundary layer pressure is approximately imposed by the outer flow

 A5_VISCOUS_DOMINANCE_NORMAL:
  Normal viscous gradients remain important within the layer even when streamwise viscous diffusion is asymptotically small

 A6_SEPARATION:
  Classical separation is associated with wall shear approaching zero and flow reversal tendencies

 A7_TRANSITION:
  Boundary layers can transition from laminar to turbulent states through instability and disturbance amplification

 A8_SCALING:
  Appropriate nondimensional variables reveal distinct inner and outer wall regions
}

REASONING {

 R1_BOUNDARY_LAYER_CONTEXT {
  INPUT = wall_bounded_flow_problem
  IDENTIFY = geometry
  IDENTIFY = external_velocity
  IDENTIFY = viscosity_and_density
  IDENTIFY = wall_condition
  IDENTIFY = pressure_gradient
  RETURN = boundary_layer_context
 }

 R2_SCALING_ANALYSIS {
  INPUT = characteristic_streamwise_scale_and_velocity
  COMPUTE = Reynolds_number
  ESTIMATE = boundary_layer_thickness
  DETERMINE = validity_of_thin_layer approximation
  RETURN = scaling_profile
 }

 R3_GOVERNING_EQUATIONS {
  INPUT = incompressible_high_Re_flow
  APPLY = boundary_layer_asymptotic scaling
  RETAIN = streamwise_advection_normal_viscous diffusion_and_outer pressure gradient
  RETURN = Prandtl_boundary_layer equations
 }

 R4_THICKNESS_REASONING {
  INPUT = velocity_profile_and_edge_velocity
  COMPUTE = delta_deltaStar_theta_shapeFactor
  RETURN = thickness_profile
 }

 R5_WALL_SHEAR_REASONING {
  INPUT = near_wall_velocity_gradient
  COMPUTE = tau_w_and_Cf
  RETURN = skin_friction_profile
 }

 R6_SIMILARITY_REASONING {
  INPUT = geometry_and_outer_velocity law
  TEST = similarity conditions
  IF zero_pressure_gradient_flat_plate
   USE = Blasius_solution
  ELSE IF power_law_outer_velocity
   CONSIDER = FalknerSkan_solution
  RETURN = similarity_profile
 }

 R7_SEPARATION_REASONING {
  INPUT = pressure_gradient_and_wall_shear
  TRACK = tau_w_along_surface
  IF tau_w approaches_zero_under_adverse_gradient
   IDENTIFY = separation_risk
  RETURN = separation_profile
 }

 R8_TRANSITION_REASONING {
  INPUT = laminar_boundary_layer_disturbances_and_Re
  ANALYSE = instability_growth_TollmienSchlichting_or_bypass transition
  RETURN = transition_profile
 }

 R9_TURBULENT_WALL_REASONING {
  INPUT = turbulent_boundary_layer
  COMPUTE = friction_velocity_yPlus_uPlus
  IDENTIFY = viscous_sublayer_buffer_and_log regions
  RETURN = wall_scaling_profile
 }

 R10_VALIDATION {
  INPUT = analytical_or_numerical_boundary_layer result
  CHECK = matching_wall_condition_mass_balance_shear_pressure_gradient_mesh resolution_and_transition assumptions
  RETURN = validated_boundary_layer_status
 }
}

CONSTRAINTS {
 C1 = "Classical boundary-layer equations require a thin-layer high-Reynolds-number scaling."
 C2 = "Strong separation can invalidate classical attached boundary-layer approximations."
 C3 = "Pressure is not generally constant along the boundary layer."
 C4 = "Blasius theory assumes steady incompressible laminar zero-pressure-gradient flat-plate flow."
 C5 = "Falkner–Skan similarity requires a compatible outer velocity law."
 C6 = "Transition Reynolds numbers are not universal and depend on disturbances and surface conditions."
 C7 = "Wall functions require appropriate y-plus ranges."
 C8 = "Turbulent boundary-layer profiles require averaging conventions."
 C9 = "Thermal and velocity boundary-layer thicknesses depend on Prandtl number."
 C10 = "Numerical near-wall resolution must be consistent with the turbulence or wall model."
}

SEMANTIC_EQUIVALENCE {
 "BoundaryLayer" <=> "ViscousBoundaryLayer"
 "DisplacementThickness" <=> "BoundaryLayerDisplacementThickness"
 "MomentumThickness" <=> "BoundaryLayerMomentumThickness"
 "SkinFrictionCoefficient" <=> "WallFrictionCoefficient"
 "FrictionVelocity" <=> "ShearVelocity"
 "LawOfTheWall" <=> "WallLaw"
}

VALIDATION {
 V1 = "Wall geometry and outer-flow conditions are explicit."
 V2 = "Reynolds number is computed with consistent scales."
 V3 = "Thin-layer assumptions are justified."
 V4 = "Wall and matching boundary conditions are correct."
 V5 = "Thickness integrals use a consistent edge velocity."
 V6 = "Wall shear and skin friction use correct sign conventions."
 V7 = "Pressure-gradient classification is correct."
 V8 = "Separation claims include wall-shear evidence."
 V9 = "Transition model or criterion is documented."
 V10 = "Near-wall numerical resolution matches the selected modelling approach."
}

CONFIDENCE {
 BASE_CONFIDENCE = 0.99
 BOUNDARY_LAYER_DEFINITION = 0.99
 SCALING_REASONING = 0.99
 GOVERNING_EQUATION_REASONING = 0.99
 THICKNESS_REASONING = 0.99
 WALL_SHEAR_REASONING = 0.99
 SIMILARITY_REASONING = 0.98
 SEPARATION_REASONING = 0.98
 TRANSITION_REASONING = 0.97
 TURBULENT_WALL_REASONING = 0.98

 POLICY =
  "Reduce confidence when outer velocity, wall condition, Reynolds number, pressure gradient, transition state, turbulence model or near-wall numerical resolution are underspecified."
}

AI_CONSUMPTION {
 PURPOSES = [
  SemanticSearch,
  OntologyGrounding,
  BoundaryLayerReasoning,
  BoundaryLayerScalingReasoning,
  WallShearReasoning,
  SkinFrictionReasoning,
  DisplacementThicknessReasoning,
  MomentumThicknessReasoning,
  SeparationReasoning,
  TransitionReasoning,
  BlasiusReasoning,
  FalknerSkanReasoning,
  TurbulentWallReasoning,
  ThermalBoundaryLayerReasoning,
  SimilarityReasoning,
  KnowledgeGraphConstruction,
  RetrievalAugmentation,
  RecursiveInference
 ]

 NORMALISE {
  "boundary layer" -> BoundaryLayer
  "laminar boundary layer" -> LaminarBoundaryLayer
  "turbulent boundary layer" -> TurbulentBoundaryLayer
  "boundary layer thickness" -> BoundaryLayerThickness
  "displacement thickness" -> DisplacementThickness
  "momentum thickness" -> MomentumThickness
  "skin friction" -> SkinFriction
  "wall shear stress" -> WallShearStress
  "Blasius solution" -> BlasiusSolution
  "Falkner-Skan" -> FalknerSkanEquation
 }

 INTERPRETATION_ORDER = [
  detect_boundary_layer_context,
  identify geometry_outer_velocity_wall_conditions_pressure_gradient_and_fluid properties,
  compute Reynolds_number_and_thin_layer scaling,
  select laminar_turbulent_transitional_velocity_or_thermal boundary-layer pathway,
  compute velocity_profile_thicknesses_wall shear_and_skin friction,
  assess pressure_gradient_and_separation,
  apply similarity solutions when valid,
  analyse transition_or_turbulent wall scaling when relevant,
  validate matching_wall conditions_and_numerical resolution,
  return semantic output
 ]
}

EXECUTION_RULES {
 E1:
  IF query_mentions("boundary layer")
  OR thin_near_wall_viscous_region_is_present
  THEN activate(BoundaryLayerOntology)

 E2:
  IF high_Re_attached_laminar_wall_flow
  THEN consider Prandtl_boundary_layer equations

 E3:
  IF zero_pressure_gradient_flat_plate
  THEN consider BlasiusSolution

 E4:
  IF outer_velocity_follows_power_law
  THEN consider FalknerSkanEquation

 E5:
  IF adverse_pressure_gradient
  THEN assess separation_risk

 E6:
  IF wall_shear_changes_sign
  THEN identify separated_or_reversed flow

 E7:
  IF turbulent_wall_flow
  THEN compute wall_units_and_region classification

 E8:
  IF transition_is_relevant
  THEN analyse disturbance_growth_and_transition mechanism

 E9:
  IF numerical_solution
  THEN verify near_wall resolution_and_outer matching
}

RECURSION {
 ENTRY = BoundaryLayer

 EXPAND(BoundaryLayer) -> [
  LaminarBoundaryLayer,
  TurbulentBoundaryLayer,
  TransitionalBoundaryLayer,
  VelocityBoundaryLayer,
  ThermalBoundaryLayer,
  NoSlipCondition,
  WallShearStress,
  SkinFriction,
  BoundaryLayerThickness,
  DisplacementThickness,
  MomentumThickness,
  EnergyThickness,
  ShapeFactor,
  OuterFlow,
  EdgeVelocity,
  PressureGradient,
  FavourablePressureGradient,
  AdversePressureGradient,
  BoundaryLayerSeparation,
  SeparationPoint,
  Reattachment,
  BoundaryLayerScaling,
  PrandtlBoundaryLayerEquations,
  BlasiusSolution,
  FalknerSkanEquation,
  SimilarityVariable,
  LocalReynoldsNumber,
  WallUnits,
  FrictionVelocity,
  ViscousSublayer,
  BufferLayer,
  LogLayer,
  LawOfTheWall,
  Transition,
  TollmienSchlichtingWave,
  HeatTransferCoefficient,
  PrandtlNumber
 ]

 EXPAND(ThicknessMeasures) -> [
  BoundaryLayerThickness,
  DisplacementThickness,
  MomentumThickness,
  EnergyThickness,
  ShapeFactor
 ]

 EXPAND(WallStructure) -> [
  FrictionVelocity,
  WallUnits,
  ViscousSublayer,
  BufferLayer,
  LogLayer,
  LawOfTheWall
 ]

 STOP_CONDITION =
  "Stop when thin-layer scaling, velocity or thermal profile, thickness measures, wall shear, pressure-gradient effects, separation, transition, wall scaling and numerical validity are sufficiently resolved."
}

ROUTING {
 PARENT_ONTOLOGY = "Fluid Mathematics"

 IMMEDIATE_CONTEXTS = [
  "Fluid Dynamics Mathematics Ontology",
  "Navier–Stokes Ontology",
  "Turbulence Mathematics Ontology",
  "Partial Differential Equation Ontology"
 ]

 RELATED_ONTOLOGIES = [
  "Fluid Mathematics",
  "Fluid Dynamics Mathematics Ontology",
  "Navier–Stokes Ontology",
  "Turbulence Mathematics Ontology",
  "Continuity Equation Ontology",
  "Stability Ontology",
  "Nonlinear Dynamics Ontology",
  "Heat Transfer Ontologies",
  "Similarity Method Ontologies",
  "Asymptotic Analysis Ontologies",
  "Computational Fluid Dynamics Ontologies",
  "Numerical Analysis Ontologies"
 ]

 ROUTE_RULES = [
  "Boundary Layer -> Fluid Mathematics for parent semantics",
  "Boundary Layer -> Fluid Dynamics Mathematics for wall-bounded flow interpretation",
  "Boundary Layer -> Navier–Stokes for asymptotic derivation",
  "Boundary Layer -> Turbulence Mathematics for turbulent wall structure",
  "Boundary Layer -> Continuity Equation for mass conservation",
  "Boundary Layer -> Stability for transition analysis",
  "Boundary Layer -> Heat Transfer for thermal boundary layers",
  "Boundary Layer -> Similarity Methods for Blasius and Falkner-Skan reductions",
  "Boundary Layer -> Asymptotic Analysis for thin-layer scaling",
  "Boundary Layer -> CFD and Numerical Analysis for near-wall discretisation"
 ]
}

UPDATE_MODEL {
 MODE = "append-compatible semantic versioning"

 MAJOR = "ontology-breaking conceptual change"
 MINOR = "new compatible boundary-layer classes, similarity solutions or reasoning pathways"
 PATCH = "clarification, metadata or formatting correction"

 RULES = [
  "Preserve thin-layer semantics.",
  "Preserve wall-matching semantics.",
  "Preserve laminar-versus-turbulent distinction.",
  "Preserve pressure-gradient and separation semantics.",
  "Preserve thickness-measure definitions.",
  "Preserve wall-unit semantics.",
  "Preserve transition assumptions.",
  "Preserve machine-readable boundary-layer semantics."
 ]
}

OUTPUT {
 CANONICAL_DEFINITION =
  "A boundary layer is a thin near-boundary region in which viscous and transport effects become important because field gradients are large."

 SCALING_SUMMARY =
  "Boundary-layer equations arise from high-Reynolds-number asymptotic scaling of the Navier–Stokes equations."

 THICKNESS_SUMMARY =
  "Displacement and momentum thickness quantify mass-flow and momentum deficits relative to the outer flow."

 SHEAR_SUMMARY =
  "Wall shear stress determines skin-friction drag."

 SEPARATION_SUMMARY =
  "Adverse pressure gradients can reduce wall shear to zero and produce boundary-layer separation."

 LAMINAR_SUMMARY =
  "Blasius and Falkner-Skan similarity solutions describe important classes of laminar boundary layers."

 TURBULENT_SUMMARY =
  "Turbulent boundary layers contain viscous, buffer, logarithmic and outer regions described by wall scaling."

 VALIDATION_SUMMARY =
  "Boundary-layer analysis should be checked for matching, pressure-gradient assumptions, separation, transition and near-wall numerical resolution."
}

FLOW {
 INPUT
 -> detect_boundary_layer_context
 -> identify geometry_outer_flow_wall conditions_fluid properties_pressure gradient_and_characteristic scales
 -> compute Reynolds_number_and_boundary_layer scaling
 -> classify laminar_turbulent_transitional_velocity_thermal_or_concentration boundary layer
 -> solve_or_approximate boundary_layer velocity_temperature_or_species profile
 -> compute thickness_measures_wall_shear_skin friction_and_shape factor
 -> assess favourable_or_adverse pressure gradient_and_separation
 -> if_similarity_conditions apply Blasius_FalknerSkan_or_related reduction
 -> if_transition analyse instability_and_disturbance amplification
 -> if_turbulent compute friction_velocity_wall units_and_inner_outer regions
 -> validate matching_wall conditions_mass conservation_and_numerical resolution
 -> route to fluid_mathematics fluid_dynamics NavierStokes turbulence continuity stability heat_transfer similarity asymptotic_analysis CFD_or_numerical_analysis ontology
 -> recursively_expand_required_dependencies
 -> verify_result
 -> assign_confidence
 -> produce_semantic_output
 -> END
}

SEMANTIC_SUMMARY {
 "The Boundary Layer Ontology defines thin near-wall viscous and transport regions. It supports laminar, turbulent and transitional boundary layers, velocity, thermal and concentration layers, no-slip conditions, wall shear and skin friction, boundary-layer, displacement, momentum and energy thicknesses, shape factor, outer-flow matching, pressure-gradient effects, separation and reattachment, Prandtl boundary-layer equations, Blasius and Falkner-Skan similarity solutions, local Reynolds number, wall units, friction velocity, viscous sublayer, buffer and log regions, law of the wall, transition, Tollmien-Schlichting waves and thermal-transfer measures."
}

FLOW_HASH {
 METHOD = "semantic-content-identity"
 ID = "KIRETH-MATH-APPLIED-MATHEMATICS-BOUNDARY-LAYER-ONTOLOGY-V1"
}

}

END_FLOW