Merge pull request modelica#4103 from qlambert-pro/pressure-rate

Fix unit error in SimpleLiquidWater model

Author: arunkumar-narasimhan

Modelica/Media/package.mo

@@ -2149,6 +2149,7 @@ package Examples
   model SimpleLiquidWater "Example for Water.SimpleLiquidWater medium model"
     extends Modelica.Icons.Example;
 
+    constant SI.PressureRate pressureRate = 1e5/10;
     parameter SI.Volume V=1 "Volume";
     parameter SI.EnthalpyFlowRate H_flow_ext=1.e6
       "Constant enthalpy flow rate into the volume";
@@ -2182,7 +2183,7 @@ package Examples
     der(U) = H_flow_ext;
 
     // Smooth state
-    medium2.p = 1e5*time/10;
+    medium2.p = pressureRate*time;
     medium2.T = 330;
     m_flow_ext2 = time - 30;
     state = Medium.setSmoothState(

Modelica/Units.mo

@@ -342,6 +342,10 @@ end UsersGuide;
         displayUnit="bar");
     type AbsolutePressure = Pressure (min=0.0, nominal = 1e5);
     type PressureDifference = Pressure;
+    type PressureRate = Real (
+        final quantity="PressureRate",
+        final unit="Pa/s",
+        displayUnit="bar/s");
     type BulkModulus = AbsolutePressure;
     type Stress = Real (final unit="Pa");
     type NormalStress = Stress;