Buildings.Airflow.Multizone.BaseClasses.Examples

Collection of models that illustrate model use and test models

Information

This package contains examples for the use of models that can be found in Buildings.Airflow.Multizone.BaseClasses.

Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).

Package Content

Name	Description
PowerLaw	Test model for power law function
PowerLawFixedM	Test model for power law function
WindPressureLowRise	Test model for wind pressure function

Buildings.Airflow.Multizone.BaseClasses.Examples.PowerLaw

Test model for power law function

Information

This examples demonstrates the Buildings.Airflow.Multizone.BaseClasses.powerLaw function.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Parameters

Type	Name	Default	Description
Real	k	2/10^m	Flow coefficient, k = V_flow/ dp^m
Real	m	0.5	Flow exponent, m=0.5 for turbulent, m=1 for laminar
PressureDifference	dp_turbulent	5	Pressure difference where regularization starts [Pa]

Modelica definition

model PowerLaw "Test model for power law function" extends Modelica.Icons.Example; parameter Real k = 2/10^m "Flow coefficient, k = V_flow/ dp^m"; parameter Real m(min=0.5, max=1) = 0.5 "Flow exponent, m=0.5 for turbulent, m=1 for laminar"; parameter Modelica.SIunits.PressureDifference dp_turbulent(min=0)=5 "Pressure difference where regularization starts"; Modelica.SIunits.PressureDifference dp "Pressure difference"; Modelica.SIunits.VolumeFlowRate V_flow "Volume flow rate"; equation dp = 10*(-1+2*time); V_flow = Buildings.Airflow.Multizone.BaseClasses.powerLaw( dp=dp, k=k, m=m, dp_turbulent=dp_turbulent); end PowerLaw;

Buildings.Airflow.Multizone.BaseClasses.Examples.PowerLawFixedM

Test model for power law function

Information

This examples demonstrates the Buildings.Airflow.Multizone.BaseClasses.powerLaw and Buildings.Airflow.Multizone.BaseClasses.powerLawFixedM functions. They need to return the same function value. This is verified by an assert statement.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Parameters

Type	Name	Default	Description
Real	k	2/10^m	Flow coefficient, k = V_flow/ dp^m
PressureDifference	dp_turbulent	5	Pressure difference where regularization starts [Pa]

Modelica definition

model PowerLawFixedM "Test model for power law function" extends Modelica.Icons.Example; parameter Real k = 2/10^m "Flow coefficient, k = V_flow/ dp^m"; constant Real m(min=0.5, max=1) = 0.5 "Flow exponent, m=0.5 for turbulent, m=1 for laminar"; parameter Modelica.SIunits.PressureDifference dp_turbulent(min=0)=5 "Pressure difference where regularization starts"; Modelica.SIunits.PressureDifference dp "Pressure difference"; Modelica.SIunits.VolumeFlowRate V_flow "Volume flow rate computed with model powerLaw"; Modelica.SIunits.VolumeFlowRate VFixed_flow "Volume flow rate computed with model powerLawFixed"; constant Real gamma(min=1) = 1.5 "Normalized flow rate where dphi(0)/dpi intersects phi(1)"; constant Real a = gamma "Polynomial coefficient for regularized implementation of flow resistance"; constant Real b = 1/8*m^2 - 3*gamma - 3/2*m + 35.0/8 "Polynomial coefficient for regularized implementation of flow resistance"; constant Real c = -1/4*m^2 + 3*gamma + 5/2*m - 21.0/4 "Polynomial coefficient for regularized implementation of flow resistance"; constant Real d = 1/8*m^2 - gamma - m + 15.0/8 "Polynomial coefficient for regularized implementation of flow resistance"; equation dp = 10*(-1+2*time); V_flow = Buildings.Airflow.Multizone.BaseClasses.powerLaw( dp=dp, k=k, m=m, dp_turbulent=dp_turbulent); VFixed_flow = Buildings.Airflow.Multizone.BaseClasses.powerLawFixedM( k=k, dp=dp, m=m, a=a, b=b, c=c, d=d, dp_turbulent=dp_turbulent); assert(abs(V_flow-VFixed_flow) < 1E-10, "Error: The two implementations of the power law model need to give identical results"); end PowerLawFixedM;

Buildings.Airflow.Multizone.BaseClasses.Examples.WindPressureLowRise

Test model for wind pressure function

Information

This examples demonstrates the Buildings.Airflow.Multizone.BaseClasses.windPressureLowRise function.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Parameters

Type	Name	Default	Description
Real	Cp0	0.6	Wind pressure coefficient for normal wind incidence angle
Real	G	Modelica.Math.log(0.5)	Natural logarithm of side ratio

Modelica definition

model WindPressureLowRise "Test model for wind pressure function" extends Modelica.Icons.Example; parameter Real Cp0 = 0.6 "Wind pressure coefficient for normal wind incidence angle"; Modelica.SIunits.Angle incAng "Wind incidence angle (0: normal to wall)"; parameter Real G = Modelica.Math.log(0.5) "Natural logarithm of side ratio"; Real Cp "Wind pressure coefficient"; equation incAng=time*2*Modelica.Constants.pi; Cp = Buildings.Airflow.Multizone.BaseClasses.windPressureLowRise( Cp0=Cp0, G=G, incAng=incAng); end WindPressureLowRise;