calculate_reynolds_number

Instructions

Determines flow regime (laminar, transitional, turbulent).

Args:
    velocity: Flow velocity in m/s
    characteristic_length: Characteristic length in meters (pipe diameter, etc.)
    fluid_density: Fluid density in kg/m³
    dynamic_viscosity: Dynamic viscosity in Pa·s (water=0.001, air=1.8e-5)

Returns:
    Dict containing:
        - reynolds_number: Re (dimensionless)
        - flow_regime: "laminar" (Re<2300), "transitional" (2300-4000), "turbulent" (Re>4000)

Example - Water in pipe:
    result = await calculate_reynolds_number(
        velocity=2.0,  # m/s
        characteristic_length=0.05,  # 5cm diameter
        fluid_density=1000,  # water
        dynamic_viscosity=0.001
    )
    # Re = 100,000 → turbulent

Implementation Reference

• src/chuk_mcp_physics/tools/fluid.py:454-494 (handler)

  MCP tool handler (async) that defines the calculate_reynolds_number tool. Accepts velocity, characteristic_length, fluid_density, and dynamic_viscosity as parameters, creates a ReynoldsNumberRequest, delegates to the core calculation, and returns a dict.

  @tool  # type: ignore[arg-type]
  async def calculate_reynolds_number(
      velocity: float,
      characteristic_length: float,
      fluid_density: float,
      dynamic_viscosity: float,
  ) -> dict:
      """Calculate Reynolds number: Re = ρvL/μ.
  
      Determines flow regime (laminar, transitional, turbulent).
  
      Args:
          velocity: Flow velocity in m/s
          characteristic_length: Characteristic length in meters (pipe diameter, etc.)
          fluid_density: Fluid density in kg/m³
          dynamic_viscosity: Dynamic viscosity in Pa·s (water=0.001, air=1.8e-5)
  
      Returns:
          Dict containing:
              - reynolds_number: Re (dimensionless)
              - flow_regime: "laminar" (Re<2300), "transitional" (2300-4000), "turbulent" (Re>4000)
  
      Example - Water in pipe:
          result = await calculate_reynolds_number(
              velocity=2.0,  # m/s
              characteristic_length=0.05,  # 5cm diameter
              fluid_density=1000,  # water
              dynamic_viscosity=0.001
          )
          # Re = 100,000 → turbulent
      """
      from ..fluid_advanced import ReynoldsNumberRequest, calculate_reynolds_number as calc_reynolds
  
      request = ReynoldsNumberRequest(
          velocity=velocity,
          characteristic_length=characteristic_length,
          fluid_density=fluid_density,
          dynamic_viscosity=dynamic_viscosity,
      )
      response = calc_reynolds(request)
      return response.model_dump()

• src/chuk_mcp_physics/fluid_advanced.py:289-321 (handler)

  Core implementation of Reynolds number calculation using Re = (rho * v * L) / mu. Determines flow regime: laminar (<2300), transitional (2300-4000), or turbulent (>4000).

  def calculate_reynolds_number(request: ReynoldsNumberRequest) -> ReynoldsNumberResponse:
      """Calculate Reynolds number: Re = ρvL/μ.
  
      The Reynolds number characterizes the flow regime:
      - Re < 2300: Laminar flow
      - 2300 < Re < 4000: Transitional flow
      - Re > 4000: Turbulent flow
  
      Args:
          request: Reynolds number request
  
      Returns:
          Reynolds number and flow regime
      """
      rho = request.fluid_density
      v = request.velocity
      L = request.characteristic_length
      mu = request.dynamic_viscosity
  
      Re = (rho * v * L) / mu
  
      # Determine flow regime
      if Re < 2300:
          regime = "laminar"
      elif Re < 4000:
          regime = "transitional"
      else:
          regime = "turbulent"
  
      return ReynoldsNumberResponse(
          reynolds_number=Re,
          flow_regime=regime,
      )

• src/chuk_mcp_physics/fluid_advanced.py:100-108 (schema)

  Pydantic request model for Reynolds number calculation with velocity, characteristic_length, fluid_density, and dynamic_viscosity fields.

  class ReynoldsNumberRequest(BaseModel):
      """Request for Reynolds number calculation."""
  
      velocity: float = Field(..., description="Flow velocity in m/s", gt=0.0)
      characteristic_length: float = Field(
          ..., description="Characteristic length (diameter, chord) in meters", gt=0.0
      )
      fluid_density: float = Field(..., description="Fluid density in kg/m³", gt=0.0)
      dynamic_viscosity: float = Field(..., description="Dynamic viscosity in Pa⋅s", gt=0.0)

• src/chuk_mcp_physics/fluid_advanced.py:111-115 (schema)

  Pydantic response model for Reynolds number containing reynolds_number (float) and flow_regime (string).

  class ReynoldsNumberResponse(BaseModel):
      """Response for Reynolds number."""
  
      reynolds_number: float = Field(..., description="Reynolds number (dimensionless)")
      flow_regime: str = Field(..., description="Flow regime: laminar, transitional, or turbulent")

• src/chuk_mcp_physics/tools/fluid.py:454-455 (registration)

  Tool registered via @tool decorator on the async calculate_reynolds_number function, making it available as an MCP tool.

  @tool  # type: ignore[arg-type]
  async def calculate_reynolds_number(