Modelica.Fluid.Dissipation.Utilities.Records.PressureLoss

Information

Package Content

Name	Description
Bend	Input for bend
Geometry	Input for several geometries of internal flow
Orifice	Input for orifice
PressureLossInput	Input for pressure loss calculation
StraightPipe	Input for straight pipe
Tjunction	Input for T-junction
Diffuser	Input for diffuser
EdgedBend	Input for bend
SuddenChange	Input for sudden change of diameter

Modelica.Fluid.Dissipation.Utilities.Records.PressureLoss.Bend

Information

Parameters

Type	Name	Default	Description
Bend
Diameter	d_hyd	0.1	Hydraulic diameter [m]
Angle	delta	90*PI/180	Angle of turning [rad]
Length	K	0	Roughness (absolute average height of surface asperities) [m]
Radius	R_0	0.5*d_hyd	Curvature radius [m]

Modelica definition

record Bend "Input for bend"
  extends EdgedBend;
  SI.Radius R_0=0.5*d_hyd "Curvature radius";

end Bend;

Modelica.Fluid.Dissipation.Utilities.Records.PressureLoss.Geometry

Information

Parameters

Type	Name	Default	Description
Channel
GeometryOfInternalFlow	geometry	Modelica.Fluid.Dissipation.U...	Choice of geometry for internal flow
Length	K	0	Roughness (average height of surface asperities) [m]
Length	L	1	Length [m]
Annular cross sectional area
Diameter	d_ann	d_cir	Small diameter [m]
Diameter	D_ann	2*d_ann	Large diameter [m]
Circular cross sectional area
Diameter	d_cir	0.1	Internal diameter [m]
Elliptical cross sectional area
Length	a_ell	(3/4)*d_cir	Half length of long base line [m]
Length	b_ell	0.5*a_ell	Half length of short base line [m]
Rectangular cross sectional area
Length	a_rec	d_cir	Horizontal length [m]
Length	b_rec	a_rec	Vertical length [m]
Length	a_tri	d_cir*(1 + 2^0.5)	Length of base line [m]
Triangle cross sectional area
Length	h_tri	0.5*a_tri	Heigth to top angle perpendicular to base line [m]
Angle	beta	90*PI/180	Top angle [rad]

Modelica definition

record Geometry "Input for several geometries of internal flow"
  extends Modelica.Icons.Record;

  Modelica.Fluid.Dissipation.Utilities.Types.GeometryOfInternalFlow
    geometry=
      Modelica.Fluid.Dissipation.Utilities.Types.GeometryOfInternalFlow.Circular 
    "Choice of geometry for internal flow";

  SI.Length K=0 "Roughness (average height of surface asperities)";
  SI.Length L=1 "Length";

  //geometry variables
  //annular(1)
  SI.Diameter d_ann=d_cir "Small diameter";
  SI.Diameter D_ann=2*d_ann "Large diameter";
  //circular(2)
  SI.Diameter d_cir=0.1 "Internal diameter";
  //elliptical(3)
  SI.Length a_ell=(3/4)*d_cir "Half length of long base line";
  SI.Length b_ell=0.5*a_ell "Half length of short base line";
  //rectangular(4)
  SI.Length a_rec=d_cir "Horizontal length";
  SI.Length b_rec=a_rec "Vertical length";
  //triangular(5)
  SI.Length a_tri=d_cir*(1 + 2^0.5) "Length of base line";
  SI.Length h_tri=0.5*a_tri "Heigth to top angle perpendicular to base line";
  SI.Angle beta=90*PI/180 "Top angle";
end Geometry;

Modelica.Fluid.Dissipation.Utilities.Records.PressureLoss.Orifice

Information

Parameters

Type	Name	Default	Description
Orifice
Area	A_0	0.1*A_1	Cross sectional area of vena contraction [m2]
Length	C_0	0.1*C_1	Perimeter of vena contraction [m]
Area	A_1	PI*0.01^2/4	Large cross sectional area of orifice [m2]
Length	C_1	PI*0.01	Large perimeter of orifice [m]
Length	L	1e-3	Length of vena contraction [m]

Modelica definition

record Orifice "Input for orifice"

  extends Modelica.Icons.Record;

  SI.Area A_0=0.1*A_1 "Cross sectional area of vena contraction";
  SI.Length C_0=0.1*C_1 "Perimeter of vena contraction";
  SI.Area A_1=PI*0.01^2/4 "Large cross sectional area of orifice";
  SI.Length C_1=PI*0.01 "Large perimeter of orifice";
  SI.Length L=1e-3 "Length of vena contraction";
end Orifice;

Modelica.Fluid.Dissipation.Utilities.Records.PressureLoss.PressureLossInput

Information

Parameters

Type	Name	Default	Description
Input
PressureLossTarget	target	Dissipation.Utilities.Types....	Target variable of calculation
Pressure	dp	0	Pressure loss [Pa]
MassFlowRate	m_flow	0	Mass flow rate [kg/s]

Modelica definition

record PressureLossInput "Input for pressure loss calculation"
  extends Modelica.Icons.Record;

  //target variables
  Modelica.Fluid.Dissipation.Utilities.Types.PressureLossTarget target=Dissipation.Utilities.Types.PressureLossTarget.PressureLoss 
    "Target variable of calculation";

  SI.Pressure dp=0 "Pressure loss";
  SI.MassFlowRate m_flow=0 "Mass flow rate";

end PressureLossInput;

Modelica.Fluid.Dissipation.Utilities.Records.PressureLoss.StraightPipe

Information

Parameters

Type	Name	Default	Description
Straight pipe
Diameter	d_hyd	0.1	Hydraulic diameter [m]
Length	L	1	Length [m]

Modelica definition

record StraightPipe "Input for straight pipe"

  extends Modelica.Icons.Record;

  SI.Diameter d_hyd=0.1 "Hydraulic diameter";
  SI.Length L=1 "Length";
end StraightPipe;

Modelica.Fluid.Dissipation.Utilities.Records.PressureLoss.Tjunction

Information

Parameters

Type	Name	Default	Description
T-junction
Boolean	united_converging_crossection	true	true == A_cross_total = 2*A_cross_branch | false == A_cross_total > 2*A_cross_branch
Boolean	velocity_reference_branches	true	true == pressure loss coefficents w.r.t. velocity in each passage | false == w.r.t. velocity in total passage
Integer	alpha	90	Angle of branching
Diameter	d_hyd[3]	ones(3)*0.1	Hydraulic diameter of passages [side,straight,total] [m]
Restrictions
MassFlowRate	m_flow_min	1e-3	Restriction for smoothing at reverse fluid flow [kg/s]
Velocity	v_max	2e2	Restriction for maximum fluid flow velocity [m/s]
Real	zeta_TOT_max	1e3	Restriction for maximum value of pressure loss coefficient

Modelica definition

record Tjunction "Input for T-junction"
  extends Modelica.Icons.Record;

  //T-junction variables
  Boolean united_converging_crossection=true 
    "true == A_cross_total = 2*A_cross_branch | false == A_cross_total > 2*A_cross_branch";
  Boolean velocity_reference_branches=true 
    "true == pressure loss coefficents w.r.t. velocity in each passage | false == w.r.t. velocity in total passage";

  Integer alpha=90 "Angle of branching";

  SI.Diameter d_hyd[3]=ones(3)*0.1 
    "Hydraulic diameter of passages [side,straight,total]";

  //restrictions
  SI.MassFlowRate m_flow_min=1e-3 
    "Restriction for smoothing at reverse fluid flow";
  SI.Velocity v_max=2e2 "Restriction for maximum fluid flow velocity";
  Real zeta_TOT_max=1e3 
    "Restriction for maximum value of pressure loss coefficient";
end Tjunction;

Modelica.Fluid.Dissipation.Utilities.Records.PressureLoss.Diffuser

Information

Parameters

Type	Name	Default	Description
Diffuser
Angle	alpha	PI*45/180	Diffuser diverging angle [rad]
Area	A_1	PI*0.01^2/4	Small constant cross sectional area before diffuser section [m2]
Area	A_2	2*A_1	Large constant cross sectional area after diffuser section [m2]
Length	C_1	PI*0.01	Small perimeter before diffuser section [m]
Length	C_2	2*C_1	Large perimeter after diffuser section [m]
Length	L_1	0.1	Length of straight pipe before diffuser section [m]
Length	L_2	L_1	Length of straight pipe after diffuser section [m]
Length	L_d	L_1	Lenght of diffuser section (parallel to bulk fluid flow) [m]
Numerical aspects
Pressure	dp_small	1	Linearisation for a pressure loss smaller then dp_small [Pa]
Real	zeta_TOT_min	1e-3	Minimal pressure loss coefficient for infinite Reynolds number
Real	zeta_TOT_max	1e8	Maximum pressure loss coefficient for Reynolds number approaching zero

Modelica definition

record Diffuser "Input for diffuser"
  extends Modelica.Icons.Record;

  SI.Angle alpha=PI*45/180 "Diffuser diverging angle";

  SI.Area A_1=PI*0.01^2/4 
    "Small constant cross sectional area before diffuser section";
  SI.Area A_2=2*A_1 
    "Large constant cross sectional area after diffuser section";
  SI.Length C_1=PI*0.01 "Small perimeter before diffuser section";
  SI.Length C_2=2*C_1 "Large perimeter after diffuser section";
  SI.Length L_1=0.1 "Length of straight pipe before diffuser section";
  SI.Length L_2=L_1 "Length of straight pipe after diffuser section";
  SI.Length L_d=L_1 "Lenght of diffuser section (parallel to bulk fluid flow)";

  //numerical aspects
  SI.Pressure dp_small=1 
    "Linearisation for a pressure loss smaller then dp_small";
  Real zeta_TOT_min=1e-3 
    "Minimal pressure loss coefficient for infinite Reynolds number";
  Real zeta_TOT_max=1e8 
    "Maximum pressure loss coefficient for Reynolds number approaching zero";
end Diffuser;

Modelica.Fluid.Dissipation.Utilities.Records.PressureLoss.EdgedBend

Information

Parameters

Type	Name	Default	Description
Bend
Diameter	d_hyd	0.1	Hydraulic diameter [m]
Angle	delta	90*PI/180	Angle of turning [rad]
Length	K	0	Roughness (absolute average height of surface asperities) [m]

Modelica definition

record EdgedBend "Input for bend"
  extends Modelica.Icons.Record;

  SI.Diameter d_hyd(min=Modelica.Constants.eps) = 0.1 "Hydraulic diameter";
  SI.Angle delta=90*PI/180 "Angle of turning";
  SI.Length K=0 "Roughness (absolute average height of surface asperities)";

end EdgedBend;

Modelica.Fluid.Dissipation.Utilities.Records.PressureLoss.SuddenChange

Information

Parameters

Type	Name	Default	Description
Orifice
Area	A_1	PI*0.01^2/4	Small cross sectional area of orifice [m2]
Area	A_2	A_1	Large cross sectional area of orifice [m2]
Length	C_1	PI*0.01	Small perimeter of orifice [m]
Length	C_2	C_1	Large perimeter of orifice [m]

Modelica definition

record SuddenChange "Input for sudden change of diameter"

  extends Modelica.Icons.Record;

  SI.Area A_1=PI*0.01^2/4 "Small cross sectional area of orifice";
  SI.Area A_2=A_1 "Large cross sectional area of orifice";
  SI.Length C_1=PI*0.01 "Small perimeter of orifice";
  SI.Length C_2=C_1 "Large perimeter of orifice";
end SuddenChange;