Air Boundary

Boundary condition of Air

 Description The Air Boundary component models a generic boundary condition for the lumped thermal fluid simulation of Air.

Equations

The calculation is changed based on parameter values of Fidelity of properties and Dynamics of mass in the Air Settings component.

Fidelity of properties = Constant and Dynamics of mass = Static

 In / Outlet = Inlet Pressure is defined with: $\mathrm{port.p}=p$ Temperature is defined with: $\mathrm{port.T}=T$ Mass flow rate is defined with:  State equation: $p=\mathrm{ρ}\cdot \mathrm{HeatTransfer.Properties.Fluid.SimpleAir.R_gas}\cdot T$ $\mathrm{port.rho}=\mathrm{ρ}$ Definition of Enthalpy: $\mathrm{hflow}=\mathrm{HeatTransfer.Properties.Fluid.SimpleAir.cp}\cdot T+\mathrm{HeatTransfer.Properties.Fluid.SimpleAir.hflowoff}$ $\mathrm{port.hfow}=\mathrm{hflow}$ $u=\mathrm{hflow}-\frac{p}{\mathrm{ρ}}$ (*) The properties are defined in $\mathrm{HeatTransfer.Properties.Fluid.SimpleAir}$.  See more details in Air Settings.
 In / Outlet = Outlet State equation: $p=\mathrm{ρ}\cdot \mathrm{HeatTransfer.Properties.Fluid.SimpleAir.R_gas}\cdot T$ $\mathrm{port.rho}=\mathrm{ρ}$ Definition of Enthalpy: $\mathrm{hflow}=\mathrm{HeatTransfer.Properties.Fluid.SimpleAir.cp}\cdot T+\mathrm{HeatTransfer.Properties.Fluid.SimpleAir.hflowoff}$ $\mathrm{port.hfow}=\mathrm{hflow}$ Other definitions: $\mathrm{port.T}=\mathrm{T__boundary}$ $T=\mathrm{T__boundary}$ $p=\mathrm{port.p}$ (*) The properties are defined in $\mathrm{HeatTransfer.Properties.Fluid.SimpleAir}$.  See more details in Air Settings.
 Fidelity of properties = Constant and Dynamics of mass = Dynamic Pressure is defined with:  Temperature is defined with:  State equation: $p=\mathrm{ρ}\cdot \mathrm{HeatTransfer.Properties.Fluid.SimpleAir.R_gas}\cdot T$ Definition of Enthalpy: $\mathrm{hflow}=\mathrm{HeatTransfer.Properties.Fluid.SimpleAir.cp}\cdot T+\mathrm{HeatTransfer.Properties.Fluid.SimpleAir.hflowoff}$ $u=\mathrm{hflow}-\frac{p}{\mathrm{ρ}}$ Port's variable definitions: $\mathrm{port.p}=p$ $\mathrm{port.hflow}=\mathrm{hflow}$ $\mathrm{port.rho}=\mathrm{ρ}$ $\mathrm{port.T}=T$ (*) The properties are defined in $\mathrm{HeatTransfer.Properties.Fluid.SimpleAir}$.  See more details in Air Settings.

Fidelity of properties : Ideal Gas (NASA Polynomial) and Dynamics of mass = Static

 In / Outlet = Inlet Pressure is defined with: $\mathrm{port.p}=p$ Temperature is defined with: $\mathrm{port.T}=T$ Mass flow rate is defined with:  State equation: $p=\mathrm{ρ}\cdot \mathrm{HeatTransfer.Properties.Fluid.NASAPolyAir.R_gas}\cdot T$ $\mathrm{port.rho}=\mathrm{ρ}$ Definition of Enthalpy: $\mathrm{port.hfow}=\mathrm{hflow}$ $u=\mathrm{hflow}-\frac{p}{\mathrm{ρ}}$ (*) The properties are defined with NASA polynomials and coefficients. For details, see Air Settings. (*) $\mathrm{HeatTransfer.Properties.Fluid.NASAPoly_h_T}$ is NASA polynomial of Specific enthalpy . (*) NASA Glenn  coefficients and other properties are defined in $\mathrm{HeatTransfer.Properties.Fluid.NASAPolyAir}$.
 In / Outlet = Outlet State equation: $p=\mathrm{ρ}\cdot \mathrm{HeatTransfer.Properties.Fluid.NASAPolyAir.R_gas}\cdot T$ $\mathrm{port.rho}=\mathrm{ρ}$ Definition of Enthalpy: $\mathrm{port.hfow}=\mathrm{hflow}$ Other definitions: $\mathrm{port.T}=\mathrm{T__boundary}$ $T=\mathrm{T__boundary}$ $p=\mathrm{port.p}$ (*) The properties are defined with NASA polynomials and coefficients. For details, see Air Settings. (*) $\mathrm{HeatTransfer.Properties.Fluid.NASAPoly_h_T}$ is NASA polynomial of Specific enthalpy . (*) NASA Glenn  coefficients and other properties are defined in $\mathrm{HeatTransfer.Properties.Fluid.NASAPolyAir}$.
 Fidelity of properties : Ideal Gas (NASA Polynomial) and Dynamics of mass = Dynamic Pressure is defined with:  Temperature is defined with:  State equation: $p=\mathrm{ρ}\cdot \mathrm{HeatTransfer.Properties.Fluid.NASAPolyAir.R_gas}\cdot T$ Definition of Enthalpy:  $u=\mathrm{hflow}-\frac{p}{\mathrm{ρ}}$ Port's variable definitions: $\mathrm{port.p}=p$ $\mathrm{port.hflow}=\mathrm{hflow}$ $\mathrm{port.rho}=\mathrm{ρ}$ $\mathrm{port.T}=T$ (*) The properties are defined with NASA polynomials and coefficients. For details, see Air Settings. (*) $\mathrm{HeatTransfer.Properties.Fluid.NASAPoly_h_T}$ is NASA polynomial of Specific enthalpy . (*) NASA Glenn  coefficients and other properties are defined in $\mathrm{HeatTransfer.Properties.Fluid.NASAPolyAir}$.

Variables

 Symbol Units Description Modelica ID $p$ $\mathrm{Pa}$ Pressure p $T$ $K$ Temperature T $\mathrm{ρ}$ $\frac{\mathrm{kg}}{{m}^{3}}$ Density rho $\mathrm{hflow}$ $\frac{J}{\mathrm{kg}}$ Specific enthalpy hflow $u$ $\frac{J}{\mathrm{kg}}$ Specific energy u $\mathrm{mflow}$ $\frac{\mathrm{kg}}{s}$ Mass flow rate mflow

Connections

 Name Units Condition Description Modelica ID $\mathrm{port}$  Air Port $\mathrm{port_a}$ $\mathrm{p__in}$  if External input of Pressure is true. Input signal of Pressure condition $\mathrm{p_in}$ $\mathrm{T__in}$  if External input of Temperature is true. Input signal of Temperature condition $\mathrm{T_in}$ $\mathrm{mflow__in}$  if External input of Mass flow rate is true. Input signal of Mass flow rate condition $\mathrm{mflow_in}$

Parameters

 Symbol Default Units Description Modelica ID $\mathrm{AirSettings1}$ $-$ Specify a component of Air simulation settings Settings $\mathrm{p__boundary}$ $101325$ $\mathrm{Pa}$ Boundary condition of pressure p_boundary $\mathrm{false}$ $-$ If true, $\mathrm{p__in}$ is valid p_ext $\mathrm{T__boundary}$ $293.15$ $K$ Boundary condition of temperature T_boundary $\mathrm{false}$ $-$ If true, $\mathrm{T__in}$ is valid T_ext $\mathrm{mflow__boundary}$ $0.001$ $\frac{\mathrm{kg}}{s}$ Boundary condition of mass flow rate mflow_boundary $\mathrm{false}$ $-$ If true, $\mathrm{mflow__in}$ is valid mflow_ext $\mathrm{In}/\mathrm{Outlet}$ $\mathrm{Inlet}$ $-$ Select Inlet or Outlet if Dynamics of mass is Static. InOut