modelForcedConvection

Extends from Modelica.Thermal.HeatTransfer.Interfaces.Element1D (Partial heat transfer element with two HeatPort connectors that does not store energy).

Information

Convection

This components links the heat flow to a temperature difference between a wall and a fluid thanks to the Newton's law of cooling. The basic constitutive equation for convection is :

Where :

  • Q_flow: Heat flow rate from connector 'wall' (e.g., a plate) to connector 'fluid' (e.g., the surrounding air).
  • add_on is a user paramater to adjust if needed the Heat flow to the temperature difference dT
  • h_cv is the convective Heat transfer coefficient (Newton's coefficient)
  • A is the contact surface area between the wall and the fluid
  • dT is the Temperature difference between the wall (port_a.T) and the fluid (port_b.T)

The Heat Transfert coefficients is calculated from correlations. The correlation is set via the parameter correlation . Multiple correlations from multiple sources and for severals geometries are available. The details of correlations is in the released theoretical note.

Available geometries:

  • Flow over a flat wall: the characteristic length (Lc parameter) is the height of the wall
  • Cross flow around a cylinder: the characteristic length (Lc parameter) is external diameter of the cylinder
  • Flow within a pipe: the characteristic length (Lc parameter) is the hydraulic diameter.

Parameters

TypeNameDefaultDescription
Realadd_on1Custom add-on
Geometrical properties
SI.AreaA0Wall surface Area
SI.LengthLc1characteritic dimension for correlation
Flow properties
TAeZoSysPro.HeatTransfer.Types.ForcedConvectionCorrelationcorrelationCorrelations.flat_plate_ASHRAEForced convection Correlation
SI.CoefficientOfHeatTransferh_cv_const0Constant heat transfer coefficient (optional: if correlation 'Constant' choosen)

Connectors

TypeNameDefaultDescription
HeatPort_aport_a (from Element1D)
HeatPort_bport_b (from Element1D)
Modelica.Blocks.Interfaces.RealInputVelVelocity of fluid out of boundary layer

Components

TypeNameDefaultDescription
SI.HeatFlowRateQ_flow (from Element1D)Heat flow rate from port_a -> port_b
SI.TemperatureDifferencedT (from Element1D)port_a.T - port_b.T
Medium.TemperatureT_meanMean temperature
SI.CoefficientOfHeatTransferh_cvHeat transfert coefficient
SI.DensitydDensity of fluid at T_mean
SI.SpecificHeatCapacitycpSpecific heat capacity of fluid at T_mean
SI.DynamicViscositymuDynamic viscosity of fluid at T_mean
SI.ThermalConductivitykThermal conductivity of fluid at T_mean
SI.PrandtlNumberPrPrandtl Number
SI.ReynoldsNumberReReynolds Number
SI.NusseltNumberNuNusselt Number
SI.EnergyEEnergy passed throught the component

Contents

NameDescription
Medium