Buildings.Fluid.Actuators.BaseClasses.Examples

Information

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

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

Package Content

Name	Description
EqualPercentageDerivativeCheck
InverseExponentialDamperCheck	Test model to check implementation of inverse functions

Buildings.Fluid.Actuators.BaseClasses.Examples.EqualPercentageDerivativeCheck

Information

This example checks whether the function derivative is implemented correctly. If the derivative implementation is not correct, the model will stop with an assert statement.

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

Parameters

Type	Name	Default	Description
Real	R	50	Rangeability
Real	delta	0.01	Value where transition occurs
Real	l	0.001	Leakage

Modelica definition

model EqualPercentageDerivativeCheck
  extends Modelica.Icons.Example;

 parameter Real R = 50 "Rangeability";
 parameter Real delta = 0.01 "Value where transition occurs";
 parameter Real l = 0.001 "Leakage";
  Real x;
  Real y;
initial equation 
   y=x;
equation 
  x=Buildings.Fluid.Actuators.BaseClasses.equalPercentage(time, R, l, delta);
  der(y)=der(x);
  assert(abs(x-y) < 1E-2, "Model has an error");

end EqualPercentageDerivativeCheck;

Buildings.Fluid.Actuators.BaseClasses.Examples.InverseExponentialDamperCheck

Information

This example checks whether the inverse function is implemented correctly. After the symbolic manipulation, there should be no nonlinear equation that needs to be solved numerically. The model checks if symbolically inverting the function by replacing it with the implementation of its inverse and evaluating the function with the result of the inverse function gives identical results. If this is not the case, the model will stop with an assert statement.

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

Parameters

Type	Name	Default	Description
Real	cL[3]	{(Modelica.Math.log(k0) - b ...	Polynomial coefficients for curve fit for y < yl
Real	cU[3]	{(Modelica.Math.log(k1) - a)...	Polynomial coefficients for curve fit for y > yu
Density	rho	1.2	Mass density [kg/m3]
Boolean	linearized	false	Linearize flow vs. pressure relationship
MassFlowRate	m_flow_turbulent	0.02	[kg/s]
Damper coefficients
Real	a	-1.51	Coefficient a for damper characteristics
Real	b	0.105*90	Coefficient b for damper characteristics
Real	yL	15/90	Lower value for damper curve
Real	yU	55/90	Upper value for damper curve
Real	k0	1E6	Flow coefficient for y=0, k0 = pressure drop divided by dynamic pressure
Real	k1	0.45	Flow coefficient for y=1, k1 = pressure drop divided by dynamic pressure

Modelica definition

model InverseExponentialDamperCheck 
  "Test model to check implementation of inverse functions"
  extends Modelica.Icons.Example;
 parameter Real a(unit="")=-1.51 "Coefficient a for damper characteristics";
 parameter Real b(unit="")=0.105*90 "Coefficient b for damper characteristics";

 parameter Real yL = 15/90 "Lower value for damper curve";
 parameter Real yU = 55/90 "Upper value for damper curve";

 parameter Real k0(min=0) = 1E6 
    "Flow coefficient for y=0, k0 = pressure drop divided by dynamic pressure";
 parameter Real k1(min=0) = 0.45 
    "Flow coefficient for y=1, k1 = pressure drop divided by dynamic pressure";
 parameter Real[3] cL=
    {(Modelica.Math.log(k0) - b - a)/yL^2,
      (-b*yL - 2*Modelica.Math.log(k0) + 2*b + 2*a)/yL,
      Modelica.Math.log(k0)} "Polynomial coefficients for curve fit for y < yl";
 parameter Real[3] cU=
    {(Modelica.Math.log(k1) - a)/(yU^2 - 2*yU + 1),
    (-b*yU^2 - 2*Modelica.Math.log(k1)*yU - (-2*b - 2*a)*yU - b)/(yU^2 - 2*yU + 1),
    (Modelica.Math.log(k1)*yU^2 + b*yU^2 + (-2*b - 2*a)*yU + b + a)/(yU^2 - 2*yU + 1)} 
    "Polynomial coefficients for curve fit for y > yu";

  parameter Modelica.SIunits.Density rho=1.2 "Mass density";
  parameter Boolean linearized=false "Linearize flow vs. pressure relationship";

  Modelica.SIunits.Pressure dp1 "Pressure drop";
  Modelica.SIunits.Pressure dp2 "Pressure drop";
  Modelica.SIunits.Pressure dp3 "Pressure drop";

  Modelica.SIunits.Pressure dp1_new "Pressure drop";

  Modelica.SIunits.MassFlowRate m1_flow "Mass flow rate";
  Modelica.SIunits.MassFlowRate m2_flow "Mass flow rate";
  Modelica.SIunits.MassFlowRate m3_flow "Mass flow rate";
  Modelica.SIunits.MassFlowRate m2_flow_new "Mass flow rate";
  parameter Modelica.SIunits.MassFlowRate m_flow_turbulent = 0.02;

  constant Real conv1(unit="Pa/s") = 1;
  constant Real conv2(unit="kg/s2") = 1;
equation 
  dp1=time*conv1;
  dp1=Buildings.Fluid.Actuators.BaseClasses.exponentialDamper_m_flow(
    m_flow=m1_flow, m_flow_turbulent=m_flow_turbulent, linearized=linearized, y=0.5,
    a=a, b=b, cL=cL, cU=cU, yL=yL, yU=yU, kFixed=2, rho=rho, A=0.1);
  dp1_new=Buildings.Fluid.Actuators.BaseClasses.exponentialDamper_m_flow(
    m_flow=m1_flow, m_flow_turbulent=m_flow_turbulent, linearized=linearized, y=0.5,
    a=a, b=b, cL=cL, cU=cU, yL=yL, yU=yU, kFixed=2, rho=rho, A=0.1);

  m2_flow=time*conv2;
  m2_flow=Buildings.Fluid.Actuators.BaseClasses.exponentialDamper_dp(
    dp=dp2,m_flow_turbulent=m_flow_turbulent, linearized=linearized, y=0.5,
    a=a, b=b, cL=cL, cU=cU, yL=yL, yU=yU, kFixed=2, rho=rho, A=0.1);
  m2_flow_new=Buildings.Fluid.Actuators.BaseClasses.exponentialDamper_dp(
    dp=dp2,m_flow_turbulent=m_flow_turbulent, linearized=linearized, y=0.5,
    a=a, b=b, cL=cL, cU=cU, yL=yL, yU=yU, kFixed=2, rho=rho, A=0.1);

  dp3=Buildings.Fluid.Actuators.BaseClasses.exponentialDamper_m_flow(
    m_flow=m2_flow, m_flow_turbulent=m_flow_turbulent, linearized=linearized, y=0.5,
    a=a, b=b, cL=cL, cU=cU, yL=yL, yU=yU, kFixed=2, rho=rho, A=0.1);
  m3_flow=Buildings.Fluid.Actuators.BaseClasses.exponentialDamper_dp(
    dp=dp3,m_flow_turbulent=m_flow_turbulent, linearized=linearized, y=0.5,
    a=a, b=b, cL=cL, cU=cU, yL=yL, yU=yU, kFixed=2, rho=rho, A=0.1);

  assert(abs(m2_flow-m2_flow_new) < 1E-2, "Model has an error");
  assert(abs(m2_flow-m3_flow) < 1E-2, "Model has an error");
end InverseExponentialDamperCheck;