This package demonstrates how to solve one non-linear algebraic equation in one unknown with function Modelica.Media.Common.OneNonLinearEquation.
Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).
Name | Description |
---|---|
![]() | Solve y = A*sin(w*x) for x, given y |
![]() | Solve h = h_T(T), s = s_T(T) for T, if h or s is given for ideal gas NASA |
![]() | inverse computation for incmpressible media |
![]() | Solve h = h_TX(TX) for T, if h is given for ideal gas NASA |
This models solves the following non-linear equation
y = A*sin(w*x); -> determine x for given y
Translate model "Inverse_sine" and simulate for 0 sec. The result is printed to the output window.
Extends from Modelica.Icons.Example (Icon for runnable examples).
Type | Name | Default | Description |
---|---|---|---|
Real | y_zero | 0.5 | Desired value of A*sin(w*x) |
Real | x_min | -1.7 | Minimum value of x_zero |
Real | x_max | 1.7 | Maximum value of x_zero |
Real | A | 1 | |
Real | w | 1 | |
f_nonlinear_Data | data | Inverse_sine_definition.f_no... |
model Inverse_sine "Solve y = A*sin(w*x) for x, given y" import Modelica.Utilities.Streams.print; extends Modelica.Icons.Example; parameter Real y_zero = 0.5 "Desired value of A*sin(w*x)"; parameter Real x_min = -1.7 "Minimum value of x_zero"; parameter Real x_max = 1.7 "Maximum value of x_zero"; parameter Real A = 1; parameter Real w = 1; parameter Inverse_sine_definition.f_nonlinear_Data data= Inverse_sine_definition.f_nonlinear_Data(A=A, w=w); Real x_zero "y_zero = A*sin(w*x_zero)";encapsulated package Inverse_sine_definition "Define sine as non-linear equation to be solved" import Modelica; extends Modelica.Media.Common.OneNonLinearEquation; redeclare record extends f_nonlinear_Data "Data for nonlinear equation" Real A; Real w; end f_nonlinear_Data; redeclare function extends f_nonlinear "Non-linear equation to be solved" algorithm y := f_nonlinear_data.A*Modelica.Math.sin(f_nonlinear_data.w*x); end f_nonlinear; // Dummy definition has to be added for current Dymola (advice from Hans) redeclare function extends solve "Solution algorithm of non-linear equation" end solve; end Inverse_sine_definition ; equation x_zero = Inverse_sine_definition.solve(y_zero, x_min, x_max, f_nonlinear_data=data); print("x_zero = " + String(x_zero) + ", y_zero = " + String(y_zero) + ", A*sin(w*x_zero) = " + String(data.A*Modelica.Math.sin(data.w*x_zero)));end Inverse_sine;
Extends from Modelica.Icons.Example (Icon for runnable examples).
Type | Name | Default | Description |
---|---|---|---|
Temperature | T_min | 300 | Vary temperature linearly from T_min (time=0) upto T_max (time=1) [K] |
Temperature | T_max | 500 | Vary temperature linearly from T_min (time=0) upto T_max (time=1) [K] |
Pressure | p | 1.0e5 | Fixed pressure in model [Pa] |
model Inverse_sh_T "Solve h = h_T(T), s = s_T(T) for T, if h or s is given for ideal gas NASA" import SI = Modelica.SIunits; extends Modelica.Icons.Example; replaceable package Medium = Modelica.Media.Air.DryAirNasa constrainedby Modelica.Media.IdealGases.Common.SingleGasNasa "Medium model"; parameter SI.Temperature T_min = 300 "Vary temperature linearly from T_min (time=0) upto T_max (time=1)"; parameter SI.Temperature T_max = 500 "Vary temperature linearly from T_min (time=0) upto T_max (time=1)"; parameter SI.Pressure p = 1.0e5 "Fixed pressure in model"; final parameter SI.SpecificEnthalpy h_min = Medium.h_T(Medium.data,T_min) "Specific enthalpy at T_min"; final parameter SI.SpecificEnthalpy h_max = Medium.h_T(Medium.data,T_max) "Specific enthalpy at T_max"; final parameter SI.SpecificEntropy s_min = Medium.specificEntropy(Medium.setState_pT(p,T_min)) "Specific entropy at T_min"; final parameter SI.SpecificEntropy s_max = Medium.specificEntropy(Medium.setState_pT(p,T_max)) "Specific entropy at T_max"; SI.SpecificEnthalpy h1 "Pre-defined specific enthalpy"; SI.SpecificEnthalpy h2 "Specific enthalpy computed from T (= h1 required)"; SI.SpecificEntropy s1 "Pre-defined specific entropy"; SI.SpecificEntropy s2 "Specific entropy computed from T (= h1 required)"; SI.Temperature Th "Temperature computed from h1"; SI.Temperature Ts "Temperature computed from s1"; protected constant SI.Time timeUnit = 1.0; equation // Define specific enthalpy and specific entropy h1 = if time < 0 then h_min else if time > 1 then h_max else h_min + time/timeUnit*(h_max - h_min); s1 = if time < 0 then s_min else if time > 1 then s_max else s_min + time/timeUnit*(s_max - s_min); // Solve for temperature Th = Medium.temperature_phX(p, h1, fill(0.0,0)); Ts = Medium.temperature_psX(p, s1, fill(0.0,0)); // Check (h2 must be identical to h1) h2 = Medium.specificEnthalpy_pTX(p, Th, fill(0.0,0)); s2 = Medium.specificEntropy(Medium.setState_pT(p,Ts));end Inverse_sh_T;
Extends from Modelica.Icons.Example (Icon for runnable examples).
Type | Name | Default | Description |
---|---|---|---|
Temperature | T_min | Medium.T_min | Vary temperature linearly from T_min (time=0) upto T_max (time=1) [K] |
Temperature | T_max | Medium.T_max | Vary temperature linearly from T_min (time=0) upto T_max (time=1) [K] |
Pressure | p | 1.0e5 | Fixed pressure in model [Pa] |
model InverseIncompressible_sh_T "inverse computation for incmpressible media" import SI = Modelica.SIunits; import Cv = Modelica.SIunits.Conversions; extends Modelica.Icons.Example; replaceable package Medium = Modelica.Media.Incompressible.Examples.Glycol47 "Medium model"; parameter SI.Temperature T_min = Medium.T_min "Vary temperature linearly from T_min (time=0) upto T_max (time=1)"; parameter SI.Temperature T_max = Medium.T_max "Vary temperature linearly from T_min (time=0) upto T_max (time=1)"; parameter SI.Pressure p = 1.0e5 "Fixed pressure in model"; final parameter SI.SpecificEnthalpy h_min = Medium.h_T(Medium.T_min) "Specific enthalpy at T_min"; final parameter SI.SpecificEnthalpy h_max = Medium.h_T(Medium.T_max) "Specific enthalpy at T_max"; final parameter SI.SpecificEntropy s_min = Medium.specificEntropy(Medium.setState_pT(p,T_min)) "Specific entropy at T_min"; final parameter SI.SpecificEntropy s_max = Medium.specificEntropy(Medium.setState_pT(p,T_max)) "Specific entropy at T_max"; SI.SpecificEnthalpy h1 "Pre-defined specific enthalpy"; SI.SpecificEnthalpy h2 "Specific enthalpy computed from T (= h1 required)"; SI.SpecificEntropy s1 "Pre-defined specific entropy"; SI.SpecificEntropy s2 "Specific entropy computed from T (= h1 required)"; SI.Temperature Th "Temperature computed from h1"; SI.Temperature Ts "Temperature computed from s1"; protected constant SI.Time timeUnit = 1.0; equation // Define specific enthalpy h1 = if time < 0 then h_min else if time > 1 then h_max else h_min + time/timeUnit*(h_max - h_min); s1 = if time < 0 then s_min else if time > 1 then s_max else s_min + time/timeUnit*(s_max - s_min); // Solve for temperature Th = Medium.temperature_phX(p, h1, fill(0.0,0)); Ts = Medium.temperature_psX(p, s1, fill(0.0,0)); // Check (h2 must be identical to h1) h2 = Medium.specificEnthalpy_pTX(p, Th, fill(0.0,0)); s2 = Medium.specificEntropy(Medium.setState_pT(p, Ts));end InverseIncompressible_sh_T;
Extends from Modelica.Icons.Example (Icon for runnable examples).
Type | Name | Default | Description |
---|---|---|---|
Temperature | T_min | 300 | Vary temperature linearly from T_min (time=0) upto T_max (time=1) [K] |
Temperature | T_max | 500 | Vary temperature linearly from T_min (time=0) upto T_max (time=1) [K] |
Pressure | p | 1.0e5 | Fixed pressure in model [Pa] |
model Inverse_sh_TX "Solve h = h_TX(TX) for T, if h is given for ideal gas NASA" import SI = Modelica.SIunits; extends Modelica.Icons.Example; replaceable package Medium = Modelica.Media.IdealGases.MixtureGases.FlueGasLambdaOnePlus constrainedby Modelica.Media.IdealGases.Common.MixtureGasNasa "Medium model"; parameter SI.Temperature T_min = 300 "Vary temperature linearly from T_min (time=0) upto T_max (time=1)"; parameter SI.Temperature T_max = 500 "Vary temperature linearly from T_min (time=0) upto T_max (time=1)"; parameter SI.Pressure p = 1.0e5 "Fixed pressure in model"; SI.SpecificEnthalpy h_min = Medium.h_TX(T_min,X) "Specific enthalpy at T_min"; SI.SpecificEnthalpy h_max = Medium.h_TX(T_max,X) "Specific enthalpy at T_max"; SI.SpecificEntropy s_min = Medium.specificEntropy(Medium.setState_pTX(p,T_min,Medium.reference_X)) "Specific entropy at T_min"; SI.SpecificEntropy s_max = Medium.specificEntropy(Medium.setState_pTX(p,T_max,Medium.reference_X)) "Specific entropy at T_max"; SI.SpecificEnthalpy h1 "Pre-defined specific enthalpy"; SI.SpecificEnthalpy h2 "Specific enthalpy computed from T (= h1 required)"; SI.SpecificEntropy s1 "Pre-defined specific entropy"; SI.SpecificEntropy s2 "Specific entropy computed from T (= h1 required)"; SI.Temperature Th "Temperature computed from h1"; SI.Temperature Ts "Temperature computed from s1"; SI.MassFraction[4] X "mass fraction vector"; protected constant SI.Time timeUnit = 1.0; equation X = Medium.reference_X; // Define specific enthalpy h1 = if time < 0 then h_min else if time > 1 then h_max else h_min + time/timeUnit*(h_max - h_min); s1 = if time < 0 then s_min else if time > 1 then s_max else s_min + time/timeUnit*(s_max - s_min); // Solve for temperature Th = Medium.temperature_phX(p, h1, X); Ts = Medium.temperature_psX(p, s1, X); // Check (h2 must be identical to h1) h2 = Medium.specificEnthalpy_pTX(p, Th, X); s2 = Medium.specificEntropy(Medium.setState_pTX(p,Ts,X));end Inverse_sh_TX;