Create Equivalent Systems for Conical Poppet Valves

This example shows how to model a conical popped valve by using a composite Simscape™ component or by creating a model using Simscape blocks. To learn about how to model other kind of valves, see Model a Pressure Relief Valve in the Position-Based Translational Domain and Model a Spring in Chamber with Composite Components in the Position-Based Translational Domain.

Compare a Composite Component to an Equivalent Simscape Model

Open the PositionBasedPressureReliefValveComponentization model. Conical Poppet Valve is a Variant Subsystem that contains three variants: Composite, Position-Based Orifice, and Equivalent System, which all model a conical popped valve with different approaches. The figure below shows the Composite and Position-Based Orifice variants. The composite component uses position-based translational Mass, Hard Stop, Spacer, and World blocks. The position-based Orifice block is a modified version of the Orifice (IL) block and uses position-based translational ports for the orifice opening distance. The position-based Orifice block calculates the fluid force based on the orifice geometry.

Run the model for the two variants and compare the results.

model = 'PositionBasedPressureReliefValveComponentization';
variant = [model '/Conical Poppet Valve'];
open_system(model);
% Set Model Variant to "Composite"
set_param(variant, 'OverrideUsingVariant', 'Composite')
% Set the Simlog output name and run the model for the Composite case
set_param(model,'SimscapeLogName','simlog_Composite');
sim('PositionBasedPressureReliefValveComponentization');

% Set Model Variant to "Position-Based Orifice"
set_param(variant, 'OverrideUsingVariant', 'PositionBasedOrifice')
% Set the Simlog output name and run the model for the Position-Based
% Orifice case
set_param(model,'SimscapeLogName','simlog_PositionBasedOrifice')
sim('PositionBasedPressureReliefValveComponentization');

% Close existing figures to reset axes for livescript use
close all;

% Plot the composite variant results
PositionBasedPressureReliefValveComponentizationPlotComparison('Composite');
PositionBasedPressureReliefValveComponentizationPlotComparison('PositionBasedOrifice');
figure(h1_PositionBasedPressureReliefValveComponentization);
nexttile(1)
legend('Composite','Position-Based Orifice','location','southeast');
nexttile(2)
legend('Composite','Position-Based Orifice','location','southeast');

The two implementations return identical results. Set the model to the default settings.

set_param(model,'SimscapeLogName','simlog_PositionBasedPressureReliefValveComponentization')
set_param(variant, 'OverrideUsingVariant', 'Composite')

Compare a Composite Component to a Model That Uses Physical Signal Equations

The Equivalent System variant uses an unmodified Orifice (IL) block. This variant uses PS signals to perform the force calculations that the position-based orifice variant performed internally. The PS force signal is an input to the Actuator block, which applies the force to the Position-Based Translational network. The model canvas complexity illustrates the advantages of implementing similar modeling situations within a Simscape component instead.

This figure shows the Fluid Force Calculations subsystem.

This code runs the model in the Equivalent System variant and compares the results to the Composite variant results.

% Set Model Variant to "Equivalent System"
set_param(variant, 'OverrideUsingVariant', 'EquivalentSystem')
% Set the Simlog output name and run the model for the Equivalent System
% case
set_param(model,'SimscapeLogName','simlog_EquivalentSystem')
sim('PositionBasedPressureReliefValveComponentization');

% Close existing figures to reset axes for livescript use
close all;

% Plot the Composite variant results
PositionBasedPressureReliefValveComponentizationPlotComparison('Composite');
PositionBasedPressureReliefValveComponentizationPlotComparison('EquivalentSystem');
figure(h1_PositionBasedPressureReliefValveComponentization);
nexttile(1)
legend('Composite','Equivalent System','location','southeast');
nexttile(2)
legend('Composite','Equivalent System','location','southeast');

The results are different because the conical poppet valve composite component performs smoothing calculations, but the recreated equations model does not.

% Restore defaults
set_param(model,'SimscapeLogName','simlog_PositionBasedPressureReliefValveComponentization')
set_param(variant,'OverrideUsingVariant', 'Composite')