Calculation of the mean convective heat transfer coefficient kc for a laminar fluid flow through an even gap at different fluid flow and heat transfer situations. See more information.
Calculation of the mean convective heat transfer coefficient kc for a laminar fluid flow through an even gap at different fluid flow and heat transfer situations. See more information.
Calculation of the mean convective heat transfer coefficient kc for a laminar fluid flow through an even gap at different fluid flow and heat transfer situations. See more information.
Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
| Name | Description |
|---|---|
 kc_evenGapLaminar
| Mean heat transfer coefficient of even gap | laminar flow regime | considering boundary layer development | heat transfer at ONE or BOTH sides | identical and constant wall temperatures |
| kc_evenGapLaminar_KC
| Mean heat transfer coefficient of even gap | laminar flow regime | considering boundary layer development | heat transfer at ONE or BOTH sides | identical and constant wall temperatures |
 kc_evenGapLaminar_IN_con
| Input record for function kc_evenGapLaminar and kc_evenGapLaminar_KC |
| kc_evenGapLaminar_IN_var
| Input record for function kc_evenGapLaminar and kc_evenGapLaminar_KC |
 kc_evenGapOverall
| Mean heat transfer coefficient of even gap | overall flow regime | considering boundary layer development | heat transfer at ONE or BOTH sides | identical and constant wall temperatures | surface roughness |
| kc_evenGapOverall_KC
| Mean heat transfer coefficient of even gap | overall flow regime | considering boundary layer development | heat transfer at ONE or BOTH sides | identical and constant wall temperatures | surface roughness |
 kc_evenGapOverall_IN_con
| Input record for function kc_evenGapOverall and kc_evenGapOverall_KC |
| kc_evenGapOverall_IN_var
| Input record for function kc_evenGapOverall and kc_evenGapOverall_KC |
 kc_evenGapTurbulent
| Mean heat transfer coefficient of even gap | turbulent flow regime | developed fluid flow | heat transfer at BOTH sides | identical and constant wall temperatures |
| kc_evenGapTurbulent_KC
| Mean heat transfer coefficient of even gap | turbulent flow regime | developed fluid flow | heat transfer at BOTH sides | identical and constant wall temperatures |
 kc_evenGapTurbulent_IN_con
| Input record for function kc_evenGapTurbulent and kc_evenGapTurbulent_KC |
| kc_evenGapTurbulent_IN_var
| Input record for function kc_evenGapTurbulent and kc_evenGapTurbulent_KC |
Calculation of the mean convective heat transfer coefficient kc for a laminar fluid flow through an even gap at different fluid flow and heat transfer situations. Note that additionally a failure status is observed in this function to check if the intended boundary conditions are fulfilled. See more information.
Extends from Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d (Geometry figure for gap).
| Type | Name | Default | Description |
|---|---|---|---|
| Constant inputs | |||
| kc_evenGapLaminar_IN_con | IN_con | Input record for function kc_evenGapLaminar | |
| Variable inputs | |||
| kc_evenGapLaminar_IN_var | IN_var | Input record for function kc_evenGapLaminar | |
| Type | Name | Description |
|---|---|---|
| Output | ||
| CoefficientOfHeatTransfer | kc | Convective heat transfer coefficient [W/(m2.K)] |
| PrandtlNumber | Pr | Prandl number [1] |
| ReynoldsNumber | Re | Reynolds number [1] |
| NusseltNumber | Nu | Nusselt number [1] |
| Real | failureStatus | 0== boundary conditions fulfilled | 1== failure >> check if still meaningfull results |
function kc_evenGapLaminar
"Mean heat transfer coefficient of even gap | laminar flow regime | considering boundary layer development | heat transfer at ONE or BOTH sides | identical and constant wall temperatures"
//SOURCE: VDI-Waermeatlas, 9th edition, Springer-Verlag, 2002, Section Gb 6-10
//icon
extends Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d;
//input records
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapLaminar_IN_con
IN_con "Input record for function kc_evenGapLaminar";
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapLaminar_IN_var
IN_var "Input record for function kc_evenGapLaminar";
//output variables
output SI.CoefficientOfHeatTransfer kc "Convective heat transfer coefficient";
output SI.PrandtlNumber Pr "Prandl number";
output SI.ReynoldsNumber Re "Reynolds number";
output SI.NusseltNumber Nu "Nusselt number";
output Real failureStatus
"0== boundary conditions fulfilled | 1== failure >> check if still meaningfull results";
protected
type TYP = Modelica.Fluid.Dissipation.Utilities.Types.kc_evenGap;
Real MIN=Modelica.Constants.eps;
Real laminar=2200 "Maximum Reynolds number of laminar flow regime";
SI.Area A_cross=IN_con.s*IN_con.h "Cross sectional area of gap";
SI.Diameter d_hyd=2*IN_con.s "Hydraulic diameter";
Real prandtlMax=if IN_con.target == TYP.UndevOne then 10 else if IN_con.target
== TYP.UndevBoth then 1000 else 0 "Maximum Prandtl number";
Real prandtlMin=if IN_con.target == TYP.UndevOne or IN_con.target == TYP.UndevBoth then
0.1 else 0 "Minimum Prandtl number";
SI.Velocity velocity=abs(IN_var.m_flow)/max(MIN, IN_var.rho*A_cross)
"Mean velocity in gap";
//failure status
Real fstatus[2] "Check of expected boundary conditions";
//Documentation
algorithm
Pr := abs(IN_var.eta*IN_var.cp/max(MIN, IN_var.lambda));
Re := max(1, abs(IN_var.rho*velocity*d_hyd/max(MIN, IN_var.eta)));
kc := Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapLaminar_KC(IN_con,
IN_var);
Nu := kc*d_hyd/max(MIN, IN_var.lambda);
//failure status
fstatus[1] := if Re > laminar then 1 else 0;
fstatus[2] := if IN_con.target == TYP.UndevOne or IN_con.target == TYP.UndevBoth then
if Pr > prandtlMax or Pr < prandtlMin then 1 else 0 else 0;
failureStatus := 0;
for i in 1:size(fstatus, 1) loop
if fstatus[i] == 1 then
failureStatus := 1;
end if;
end for;
end kc_evenGapLaminar;
Calculation of the mean convective heat transfer coefficient kc for a laminar fluid flow through an even gap at different fluid flow and heat transfer situations. See more information.
Extends from Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d (Geometry figure for gap).
| Type | Name | Default | Description |
|---|---|---|---|
| Constant inputs | |||
| kc_evenGapLaminar_IN_con | IN_con | Input record for function kc_evenGapLaminar_KC | |
| Variable inputs | |||
| kc_evenGapLaminar_IN_var | IN_var | Input record for function kc_evenGapLaminar_KC | |
| Type | Name | Description |
|---|---|---|
| CoefficientOfHeatTransfer | kc | Output for function kc_evenGapLaminar_KC [W/(m2.K)] |
function kc_evenGapLaminar_KC
"Mean heat transfer coefficient of even gap | laminar flow regime | considering boundary layer development | heat transfer at ONE or BOTH sides | identical and constant wall temperatures"
//SOURCE: VDI-Waermeatlas, 9th edition, Springer-Verlag, 2002, Section Gb 6-10
//icon
extends Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d;
//input records
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapLaminar_IN_con
IN_con "Input record for function kc_evenGapLaminar_KC";
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapLaminar_IN_var
IN_var "Input record for function kc_evenGapLaminar_KC";
//output variables
output SI.CoefficientOfHeatTransfer kc
"Output for function kc_evenGapLaminar_KC";
protected
type TYP = Modelica.Fluid.Dissipation.Utilities.Types.kc_evenGap;
Real MIN=Modelica.Constants.eps;
SI.Area A_cross=max(MIN, IN_con.s*IN_con.h) "Cross sectional area of gap";
SI.Diameter d_hyd=2*IN_con.s "Hydraulic diameter";
SI.Velocity velocity=abs(IN_var.m_flow)/max(MIN, IN_var.rho*A_cross)
"Mean velocity in gap";
SI.ReynoldsNumber Re=max(1, IN_var.rho*velocity*d_hyd/max(MIN, IN_var.eta));
SI.PrandtlNumber Pr=abs(IN_var.eta*IN_var.cp/max(MIN, IN_var.lambda));
//variables for mean Nusselt number
//SOURCE: p.Gb 7, eq. 36/37
SI.NusseltNumber Nu_1=if IN_con.target == TYP.DevOne or IN_con.target == TYP.UndevOne then
4.861 else if IN_con.target == TYP.DevBoth or IN_con.target == TYP.UndevBoth then
7.541 else 0 "First Nusselt number";
//SOURCE: p.Gb 7, eq. 38
SI.NusseltNumber Nu_2=1.841*(Re*Pr*d_hyd/(max(IN_con.L, MIN)))^(1/3)
"Second Nusselt number";
//SOURCE: p.Gb 7, eq. 42
SI.NusseltNumber Nu_3=if IN_con.target == TYP.UndevOne or IN_con.target ==
TYP.UndevBoth then (2/(1 + 22*Pr))^(1/6)*(Re*Pr*d_hyd/(max(IN_con.L, MIN)))
^(0.5) else 0 "Third mean Nusselt number";
SI.NusseltNumber Nu=((Nu_1)^3 + (Nu_2)^3 + (Nu_3)^3)^(1/3);
//Documentation
algorithm
kc := Nu*((IN_var.lambda/max(MIN, d_hyd)));
end kc_evenGapLaminar_KC;
Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapLaminar_IN_con
Extends from Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_con (Input record for function kc_evenGapOverall and kc_evenGapOverall_KC).
| Type | Name | Default | Description |
|---|---|---|---|
| Even gap | |||
| kc_evenGap | target | Dissipation.Utilities.Types.... | Target variable of calculation |
| Length | h | 0.1 | Height of cross sectional area [m] |
| Length | s | 0.05 | Distance between parallel plates in cross sectional area [m] |
| Length | L | 1 | Overflowed length of gap [m] |
record kc_evenGapLaminar_IN_con "Input record for function kc_evenGapLaminar and kc_evenGapLaminar_KC" extends Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_con;end kc_evenGapLaminar_IN_con;
Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapLaminar_IN_var
Extends from Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_var (Input record for function kc_evenGapOverall and kc_evenGapOverall_KC).
| Type | Name | Default | Description |
|---|---|---|---|
| Fluid properties | |||
| SpecificHeatCapacityAtConstantPressure | cp | Specific heat capacity of fluid at constant pressure [J/(kg.K)] | |
| DynamicViscosity | eta | Dynamic viscosity of fluid [Pa.s] | |
| ThermalConductivity | lambda | Thermal conductivity of fluid [W/(m.K)] | |
| Density | rho | Density of fluid [kg/m3] | |
| Input | |||
| MassFlowRate | m_flow | [kg/s] | |
record kc_evenGapLaminar_IN_var "Input record for function kc_evenGapLaminar and kc_evenGapLaminar_KC" extends Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_var;end kc_evenGapLaminar_IN_var;
Calculation of the mean convective heat transfer coefficient kc for an overall fluid flow through an even gap at different fluid flow and heat transfer situations. Note that additionally a failure status is observed in this function to check if the intended boundary conditions are fulfilled. See more information.
Extends from Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d (Geometry figure for gap).
| Type | Name | Default | Description |
|---|---|---|---|
| Constant inputs | |||
| kc_evenGapOverall_IN_con | IN_con | Input record for function kc_evenGapOverall | |
| Variable inputs | |||
| kc_evenGapOverall_IN_var | IN_var | Input record for function kc_evenGapOverall | |
| Type | Name | Description |
|---|---|---|
| Output | ||
| CoefficientOfHeatTransfer | kc | Convective heat transfer coefficient [W/(m2.K)] |
| PrandtlNumber | Pr | Prandl number [1] |
| ReynoldsNumber | Re | Reynolds number [1] |
| NusseltNumber | Nu | Nusselt number [1] |
| Real | failureStatus | 0== boundary conditions fulfilled | 1== failure >> check if still meaningfull results |
function kc_evenGapOverall
"Mean heat transfer coefficient of even gap | overall flow regime | considering boundary layer development | heat transfer at ONE or BOTH sides | identical and constant wall temperatures | surface roughness"
//SOURCE: VDI-Waermeatlas, 9th edition, Springer-Verlag, 2002, Section Gb 6-10
//icon
extends Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d;
import SI = Modelica.SIunits;
import MIN = Modelica.Constants.eps;
// import SMOOTH = Modelica.Fluid.Dissipation.Utilities.Functions.Stepsmoother;
//input records
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_con
IN_con "Input record for function kc_evenGapOverall";
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_var
IN_var "Input record for function kc_evenGapOverall";
//output variables
output SI.CoefficientOfHeatTransfer kc "Convective heat transfer coefficient";
output SI.PrandtlNumber Pr "Prandl number";
output SI.ReynoldsNumber Re "Reynolds number";
output SI.NusseltNumber Nu "Nusselt number";
output Real failureStatus
"0== boundary conditions fulfilled | 1== failure >> check if still meaningfull results";
protected
type TYP = Modelica.Fluid.Dissipation.Utilities.Types.kc_evenGap;
Real MIN=Modelica.Constants.eps;
Real laminar=2200 "Maximum Reynolds number for laminar regime";
Real turbulent=1e4 "Minimum Reynolds number for turbulent regime";
SI.Area A_cross=IN_con.s*IN_con.h "Cross sectional area of gap";
SI.Diameter d_hyd=2*IN_con.s "Hydraulic diameter";
Real prandtlMax=if IN_con.target == TYP.UndevOne then 10 else if IN_con.target
== TYP.UndevBoth then 1000 else 0 "Maximum Prandtl number";
Real prandtlMin=if IN_con.target == TYP.UndevOne or IN_con.target == TYP.UndevBoth then
0.1 else 0 "Minimum Prandtl number";
SI.Velocity velocity=abs(IN_var.m_flow)/max(MIN, IN_var.rho*A_cross)
"Mean velocity in gap";
//failure status
Real fstatus[2] "Check of expected boundary conditions";
//Documentation
algorithm
Pr := abs(IN_var.eta*IN_var.cp/max(MIN, IN_var.lambda));
Re := max(1e-3, abs(IN_var.rho*velocity*d_hyd/max(MIN, IN_var.eta)));
kc := Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_KC(IN_con, IN_var);
Nu := kc*d_hyd/max(MIN, IN_var.lambda);
//failure status
fstatus[1] := if IN_con.target == TYP.UndevOne or IN_con.target == TYP.UndevBoth then
if Pr > prandtlMax or Pr < prandtlMin then 1 else 0 else 0;
fstatus[2] := if d_hyd/IN_con.L > 1.0 then 1 else 0;
failureStatus := 0;
for i in 1:size(fstatus, 1) loop
if fstatus[i] == 1 then
failureStatus := 1;
end if;
end for;
end kc_evenGapOverall;
Calculation of the mean convective heat transfer coefficient kc for an overall fluid flow through an even gap at different fluid flow and heat transfer situations. See more information.
Extends from Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d (Geometry figure for gap).
| Type | Name | Default | Description |
|---|---|---|---|
| Constant inputs | |||
| kc_evenGapOverall_IN_con | IN_con | Input record for function kc_evenGapOverall_KC | |
| Variable inputs | |||
| kc_evenGapOverall_IN_var | IN_var | Input record for function kc_evenGapOverall_KC | |
| Type | Name | Description |
|---|---|---|
| CoefficientOfHeatTransfer | kc | Output for function kc_evenGapOverall_KC [W/(m2.K)] |
function kc_evenGapOverall_KC
"Mean heat transfer coefficient of even gap | overall flow regime | considering boundary layer development | heat transfer at ONE or BOTH sides | identical and constant wall temperatures | surface roughness"
//SOURCE: VDI-Waermeatlas, 9th edition, Springer-Verlag, 2002, Section Gb 6-10
//icon
extends Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d;
import SMOOTH = Modelica.Fluid.Dissipation.Utilities.Functions.General.Stepsmoother;
//input records
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_con
IN_con "Input record for function kc_evenGapOverall_KC";
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_var
IN_var "Input record for function kc_evenGapOverall_KC";
//output variables
output SI.CoefficientOfHeatTransfer kc
"Output for function kc_evenGapOverall_KC";
protected
Real MIN=Modelica.Constants.eps;
Real laminar=2200 "Maximum Reynolds number for laminar regime";
Real turbulent=1e4 "Minimum Reynolds number for turbulent regime";
SI.Area A_cross=max(MIN, IN_con.s*IN_con.h) "Cross sectional area of gap";
SI.Diameter d_hyd=2*IN_con.s "Hydraulic diameter";
SI.Velocity velocity=abs(IN_var.m_flow)/max(MIN, IN_var.rho*A_cross)
"Mean velocity in gap";
SI.ReynoldsNumber Re=max(1, IN_var.rho*velocity*d_hyd/max(MIN, IN_var.eta));
SI.PrandtlNumber Pr=abs(IN_var.eta*IN_var.cp/max(MIN, IN_var.lambda));
//Documentation
algorithm
kc := SMOOTH(
laminar,
turbulent,
Re)*Dissipation.HeatTransfer.Channel.kc_evenGapLaminar_KC(
IN_con, IN_var) + SMOOTH(
turbulent,
laminar,
Re)*Dissipation.HeatTransfer.Channel.kc_evenGapTurbulent_KC(
IN_con, IN_var);
end kc_evenGapOverall_KC;
Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_con
Extends from Modelica.Fluid.Dissipation.Utilities.Records.HeatTransfer.EvenGap (Input for even gap).
| Type | Name | Default | Description |
|---|---|---|---|
| Even gap | |||
| kc_evenGap | target | Dissipation.Utilities.Types.... | Target variable of calculation |
| Length | h | 0.1 | Height of cross sectional area [m] |
| Length | s | 0.05 | Distance between parallel plates in cross sectional area [m] |
| Length | L | 1 | Overflowed length of gap [m] |
record kc_evenGapOverall_IN_con
"Input record for function kc_evenGapOverall and kc_evenGapOverall_KC"
//even gap variables
extends Modelica.Fluid.Dissipation.Utilities.Records.HeatTransfer.EvenGap;
end kc_evenGapOverall_IN_con;
Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_var
Extends from Modelica.Fluid.Dissipation.Utilities.Records.General.FluidProperties (Base record for fluid properties).
| Type | Name | Default | Description |
|---|---|---|---|
| Fluid properties | |||
| SpecificHeatCapacityAtConstantPressure | cp | Specific heat capacity of fluid at constant pressure [J/(kg.K)] | |
| DynamicViscosity | eta | Dynamic viscosity of fluid [Pa.s] | |
| ThermalConductivity | lambda | Thermal conductivity of fluid [W/(m.K)] | |
| Density | rho | Density of fluid [kg/m3] | |
| Input | |||
| MassFlowRate | m_flow | [kg/s] | |
record kc_evenGapOverall_IN_var "Input record for function kc_evenGapOverall and kc_evenGapOverall_KC" //fluid property variables extends Modelica.Fluid.Dissipation.Utilities.Records.General.FluidProperties; //input variable (mass flow rate) SI.MassFlowRate m_flow;end kc_evenGapOverall_IN_var;
Calculation of the mean convective heat transfer coefficient kc for a developed turbulent fluid flow through an even gap at heat transfer from both sides. Note that additionally a failure status is observed in this function to check if the intended boundary conditions are fulfilled. See more information.
Extends from Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d (Geometry figure for gap).
| Type | Name | Default | Description |
|---|---|---|---|
| Constant inputs | |||
| kc_evenGapTurbulent_IN_con | IN_con | Input record for function kc_evenGapTurbulent | |
| Variable inputs | |||
| kc_evenGapTurbulent_IN_var | IN_var | Input record for function kc_evenGapTurbulent | |
| Type | Name | Description |
|---|---|---|
| Output | ||
| CoefficientOfHeatTransfer | kc | Convective heat transfer coefficient [W/(m2.K)] |
| PrandtlNumber | Pr | Prandl number [1] |
| ReynoldsNumber | Re | Reynolds number [1] |
| NusseltNumber | Nu | Nusselt number [1] |
| Real | failureStatus | 0== boundary conditions fulfilled | 1== failure >> check if still meaningfull results |
function kc_evenGapTurbulent
"Mean heat transfer coefficient of even gap | turbulent flow regime | developed fluid flow | heat transfer at BOTH sides | identical and constant wall temperatures"
//SOURCE: VDI-Waermeatlas, 9th edition, Springer-Verlag, 2002, Section Gb 7
//icon
extends Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d;
import SI = Modelica.SIunits;
import MIN = Modelica.Constants.eps;
//input records
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapTurbulent_IN_con
IN_con "Input record for function kc_evenGapTurbulent";
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapTurbulent_IN_var
IN_var "Input record for function kc_evenGapTurbulent";
//output variables
output SI.CoefficientOfHeatTransfer kc "Convective heat transfer coefficient";
output SI.PrandtlNumber Pr "Prandl number";
output SI.ReynoldsNumber Re "Reynolds number";
output SI.NusseltNumber Nu "Nusselt number";
output Real failureStatus
"0== boundary conditions fulfilled | 1== failure >> check if still meaningfull results";
protected
Real MIN=Modelica.Constants.eps;
Real prandtlMax=100 "Maximum Prandtl number";
Real prandtlMin=0.6 "Minimum Prandtl number";
Real turbulentMax=1e6 "Maximum Reynolds number for turbulent flow regime";
Real turbulentMin=3e4 "Minimum Reynolds number for turbulent flow regime";
SI.Area A_cross=max(MIN, IN_con.s*IN_con.h) "Cross sectional area of gap";
SI.Diameter d_hyd=2*IN_con.s "Hydraulic diameter";
SI.Velocity velocity=abs(IN_var.m_flow)/max(MIN, IN_var.rho*A_cross)
"Mean velocity in gap";
//failure status
Real fstatus[3] "check of expected boundary conditions";
//Documentation
algorithm
Pr := abs(IN_var.eta*IN_var.cp/max(MIN, IN_var.lambda));
Re := max(1, abs(IN_var.rho*velocity*d_hyd/max(MIN, IN_var.eta)));
kc := Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapTurbulent_KC(IN_con,
IN_var);
Nu := kc*d_hyd/max(MIN, IN_var.lambda);
//failure status
fstatus[1] := if Re > turbulentMax or Re < turbulentMin then 1 else 0;
fstatus[2] := if Pr > prandtlMax or Pr < prandtlMin then 1 else 0;
fstatus[3] := if d_hyd/max(MIN, IN_con.L) > 1.0 then 1 else 0;
failureStatus := 0;
for i in 1:size(fstatus, 1) loop
if fstatus[i] == 1 then
failureStatus := 1;
end if;
end for;
end kc_evenGapTurbulent;
Calculation of the mean convective heat transfer coefficient kc for a developed turbulent fluid flow through an even gap at heat transfer from both sides. See more information.
Extends from Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d (Geometry figure for gap).
| Type | Name | Default | Description |
|---|---|---|---|
| Constant inputs | |||
| kc_evenGapTurbulent_IN_con | IN_con | Input record for function kc_evenGapTurbulent_KC | |
| Variable inputs | |||
| kc_evenGapTurbulent_IN_var | IN_var | Input record for function kc_evenGapTurbulent_KC | |
| Type | Name | Description |
|---|---|---|
| CoefficientOfHeatTransfer | kc | Output for function kc_evenGapTurbulent_KC [W/(m2.K)] |
function kc_evenGapTurbulent_KC
"Mean heat transfer coefficient of even gap | turbulent flow regime | developed fluid flow | heat transfer at BOTH sides | identical and constant wall temperatures"
//SOURCE: VDI-Waermeatlas, 9th edition, Springer-Verlag, 2002, Section Gb 7
//icon
extends Modelica.Fluid.Dissipation.Utilities.Icons.HeatTransfer.Gap1_d;
//input records
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapTurbulent_IN_con
IN_con "Input record for function kc_evenGapTurbulent_KC";
input Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapTurbulent_IN_var
IN_var "Input record for function kc_evenGapTurbulent_KC";
//output variables
output SI.CoefficientOfHeatTransfer kc
"Output for function kc_evenGapTurbulent_KC";
protected
Real MIN=Modelica.Constants.eps;
SI.Area A_cross=max(MIN, IN_con.s*IN_con.h) "Cross sectional area of gap";
SI.Diameter d_hyd=2*IN_con.s "Hydraulic diameter";
SI.Velocity velocity=abs(IN_var.m_flow)/max(MIN, IN_var.rho*A_cross)
"Mean velocity in gap";
SI.ReynoldsNumber Re=max(2.6, IN_var.rho*velocity*d_hyd/max(MIN, IN_var.eta));
SI.PrandtlNumber Pr=abs(IN_var.eta*IN_var.cp/max(MIN, IN_var.lambda));
//SOURCE: p.Ga 5, eq. 27
Real zeta=1/max(MIN, 1.8*Modelica.Math.log10(abs(Re)) - 1.5)^2
"Pressure loss coefficient";
//SOURCE: p.Gb 5, eq. 26
//assumption according to Gb 7, sec. 2.4
SI.NusseltNumber Nu=abs((zeta/8)*Re*Pr/(1 + 12.7*(zeta/8)^0.5*(Pr^(2/3) - 1))
*(1 + (d_hyd/max(MIN, IN_con.L))^(2/3)));
//Documentation
algorithm
kc := Nu*(IN_var.lambda/max(MIN, d_hyd));
end kc_evenGapTurbulent_KC;
Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapTurbulent_IN_con
Extends from Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_con (Input record for function kc_evenGapOverall and kc_evenGapOverall_KC).
| Type | Name | Default | Description |
|---|---|---|---|
| Even gap | |||
| kc_evenGap | target | 2 | Target variable of calculation |
| Length | h | 0.1 | Height of cross sectional area [m] |
| Length | s | 0.05 | Distance between parallel plates in cross sectional area [m] |
| Length | L | 1 | Overflowed length of gap [m] |
record kc_evenGapTurbulent_IN_con
"Input record for function kc_evenGapTurbulent and kc_evenGapTurbulent_KC"
extends Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_con
( final target=2);
end kc_evenGapTurbulent_IN_con;
Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapTurbulent_IN_var
Extends from Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_var (Input record for function kc_evenGapOverall and kc_evenGapOverall_KC).
| Type | Name | Default | Description |
|---|---|---|---|
| Fluid properties | |||
| SpecificHeatCapacityAtConstantPressure | cp | Specific heat capacity of fluid at constant pressure [J/(kg.K)] | |
| DynamicViscosity | eta | Dynamic viscosity of fluid [Pa.s] | |
| ThermalConductivity | lambda | Thermal conductivity of fluid [W/(m.K)] | |
| Density | rho | Density of fluid [kg/m3] | |
| Input | |||
| MassFlowRate | m_flow | [kg/s] | |
record kc_evenGapTurbulent_IN_var "Input record for function kc_evenGapTurbulent and kc_evenGapTurbulent_KC" extends Modelica.Fluid.Dissipation.HeatTransfer.Channel.kc_evenGapOverall_IN_var;end kc_evenGapTurbulent_IN_var;