Use user supplied water compressibility in Philips density calculation

.integrated_tests.yaml

@@ -1,7 +1,6 @@
 baselines:
   bucket: geosx
-  baseline: integratedTests/baseline_integratedTests-pr4164-17838-91151f5
-
+  baseline: integratedTests/baseline_integratedTests-pr4165-17850-4a6ed2e
 allow_fail:
   all: ''
-  streak: ''
+  streak: ''

BASELINE_NOTES.md

@@ -5,6 +5,10 @@ This file is designed to track changes to the integrated test baselines.
 Any developer who updates the baseline ID in the .integrated_tests.yaml file is expected to create an entry in this file with the pull request number, date, and their justification for rebaselining.
 These notes should be in reverse-chronological order, and use the following time format: (YYYY-MM-DD).
 
+PR #4165 (2026-10-29) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr4165-17850-4a6ed2e.tar.gz>
+=====================
+Add zero salinity, non-default compressibility pvt driver test
+
 PR #4164 (2026-10-26) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr4164-17838-91151f5.tar.gz>
 =====================
 Add a `Group` statistics layer for fracture surfaces.

inputFiles/constitutiveDriver/testPVT_CO2Brine.xml

@@ -93,6 +93,18 @@
       outputMassDensity="1"
       output="testPVT_CO2Brine_testCo2BrinePhillipsMixtureThermalB.txt"
       logLevel="1" />
+    <PVTDriver
+      name="testCo2BrinePhillipsZeroSalinity"
+      fluid="co2BrinePhillipsZeroSalinity"
+      feedComposition="{ 0.2, 0.8 }"
+      pressureControl="pressureFunction"
+      temperatureControl="temperatureFunction"
+      steps="20"
+      outputCompressibility="1"
+      outputPhaseComposition="1"
+      outputMassDensity="1"
+      output="testPVT_CO2Brine_testCo2BrinePhillipsZeroSalinity.txt"
+      logLevel="1" />
   </Tasks>
 
   <Outputs>
@@ -126,6 +138,9 @@
     <SoloEvent
       name="eventCo2BrinePhillipsMixtureThermalB"
       target="/Tasks/testCo2BrinePhillipsMixtureThermalB" />
+    <SoloEvent
+      name="eventCo2BrinePhillipsZeroSalinity"
+      target="/Tasks/testCo2BrinePhillipsZeroSalinity" />
 
     <PeriodicEvent
       name="restarts"
@@ -175,6 +190,17 @@
       temperatureCoordinates="{340, 460}"
       temperatureInterval="10"
       salinity="1.0" />
+    <CO2BrinePhillipsFluid
+      name="co2BrinePhillipsZeroSalinity"
+      phaseNames="{ gas, water }"
+      componentNames="{ co2, water }"
+      componentMolarWeight="{ 44e-3, 18e-3 }"
+      pressureCoordinates="{1e6, 5e7}"
+      pressureInterval="1e6"
+      temperatureCoordinates="{340, 460}"
+      temperatureInterval="10"
+      waterCompressibility="4.1e-10"
+      salinity="0.0" />
   </Constitutive>
 
   <Functions>

src/coreComponents/constitutive/fluid/multifluid/CO2Brine/functions/PhillipsBrineDensity.cpp

@@ -74,7 +74,8 @@ void calculateBrineDensity( PTTableCoordinates const & tableCoords,
 
 void calculatePureWaterDensity( PTTableCoordinates const & tableCoords,
                                 string const & functionName,
-                                array1d< real64 > const & densities )
+                                array1d< real64 > const & densities,
+                                real64 const waterCompressibility )
 {
   // if no salinity, we fall back to the standard approach in three steps
   // 1- Get the saturation density as a function of temperature
@@ -102,9 +103,6 @@ void calculatePureWaterDensity( PTTableCoordinates const & tableCoords,
       // Step 2: get the saturation pressure
       real64 const waterSatPressure = waterSatPressureTable->evaluate( &T );
       // Step 3: get the pure water density
-      // Note: for now, we keep a constant water compressibility for consistency with the Ezrokhi model
-      // In the future, we should query the water compressibility as a function of pressure and temperature in a table
-      real64 const waterCompressibility = 4.5e-10; // Pa-1 // TODO: consolidate to a unique file as Dick started doing
       densities[j*nPressures+i] = waterSatDensity * exp( waterCompressibility * ( P - waterSatPressure ) );
     }
   }
@@ -147,7 +145,8 @@ TableFunction const * makeDensityTable( BrineFluidParameters const & brineFluidP
     {
       // the Phillips correlation is inaccurate in the absence of salinity.
       // since this is a very frequent case, we implement an alternate (more accurate) method below
-      calculatePureWaterDensity( tableCoords, functionName, densities );
+      real64 const waterCompressibility = brineFluidParameters.m_waterCompressibility;
+      calculatePureWaterDensity( tableCoords, functionName, densities, waterCompressibility );
     }
 
     TableFunction * const densityTable = dynamicCast< TableFunction * >( functionManager.createChild( "TableFunction", tableName ) );