Handle multiple phases in mass balance

Author: lars-petter-hauge

frontend/src/components/Simulation/MassBalanceError.tsx

@@ -100,16 +100,16 @@ export function getMasses(concs: Record<string, number>): Record<string, number>
 }
 
 export function getMassBalanceError(
-    init: Record<string, number>,
-    final: Record<string, number>
+    initPhases: Phase[],
+    finalPhases: Phase[]
 ): {
     error: number;
     initMasses: Record<string, number>;
     finalMasses: Record<string, number>;
     substances: string[];
 } {
-    const initMasses = getMasses(init);
-    const finalMasses = getMasses(final);
+    const initMasses = getMasses(mergePhasesConcentrations(initPhases));
+    const finalMasses = getMasses(mergePhasesConcentrations(finalPhases));
     const substances = Array.from(new Set([...Object.keys(initMasses), ...Object.keys(finalMasses)]));
 
     let error = 0;
@@ -139,14 +139,13 @@ export function mergePhasesConcentrations(phases: Phase[]): Record<string, numbe
 }
 
 interface MassBalanceErrorProps {
-    initial: Record<string, number>;
-    phases: Phase[];
+    initialPhases: Phase[];
+    finalPhases: Phase[];
 }
 
-export function MassBalanceError({ initial, phases }: MassBalanceErrorProps) {
+export function MassBalanceError({ initialPhases, finalPhases }: MassBalanceErrorProps) {
     const [isExpanded, setExpanded] = useState<boolean>(false);
-    const final = mergePhasesConcentrations(phases);
-    const { error, initMasses, finalMasses, substances } = getMassBalanceError(initial, final);
+    const { error, initMasses, finalMasses, substances } = getMassBalanceError(initialPhases, finalPhases);
     const significantError = error >= 1;
 
     useEffect(() => {

frontend/src/components/Simulation/Results.tsx

@@ -79,7 +79,10 @@ const Results: React.FC<ResultsProps> = ({ simulationResults }) => {
 
             panelContents.push(
                 <Tabs.Panel key={`phase-${modelIndex}-${phase.kind}`}>
-                    <MassBalanceError initial={initialConcentrations} phases={result.phases} />
+                    <MassBalanceError
+                        initialPhases={[{ kind: "aqueous", fraction: 1, concentrations: initialConcentrations }]}
+                        finalPhases={result.phases}
+                    />
 
                     <BarChart
                         aspectRatio={2}

frontend/tests/components/MassBalanceError.test.tsx

@@ -56,18 +56,42 @@ describe("MassBalanceError", () => {
         N2: 3,
     };
 
+    const singlePhase = (concentrations: Record<string, number>) => [
+        { kind: "co2-rich" as const, fraction: 1, concentrations },
+    ];
+
     it("error is 0 when the numbers are the same", () => {
-        expect(getMassBalanceError(concs, concs).error).toBe(0);
+        expect(getMassBalanceError(singlePhase(concs), singlePhase(concs)).error).toBe(0);
     });
 
     it("error is small when difference is small", () => {
         const final = Object.fromEntries(Object.entries(concs).map(([subst, amount]) => [subst, amount + 1e-3]));
 
-        expect(getMassBalanceError(concs, final).error).toBeLessThan(0.01);
+        expect(getMassBalanceError(singlePhase(concs), singlePhase(final)).error).toBeLessThan(0.01);
     });
 
     it("error is large when order of magnitude difference is large", () => {
-        expect(getMassBalanceError(concs, { ...concs, NO2: concs.NO2 * 2 }).error).toBeGreaterThan(100.0);
-        expect(getMassBalanceError(concs, { ...concs, NO2: concs.NO2 / 2 }).error).toBeGreaterThan(100.0);
+        expect(getMassBalanceError(singlePhase(concs), singlePhase({ ...concs, NO2: concs.NO2 * 2 })).error).toBeGreaterThan(100.0);
+        expect(getMassBalanceError(singlePhase(concs), singlePhase({ ...concs, NO2: concs.NO2 / 2 })).error).toBeGreaterThan(100.0);
+    });
+
+    it("error is 0 when mass is conserved across multiple phases", () => {
+        const phases = [
+            { kind: "co2-rich" as const, fraction: 0.6, concentrations: { H2O: 1, NO2: 2, N2: 3 } },
+            { kind: "aqueous" as const, fraction: 0.4, concentrations: { H2O: 1, NO2: 2, N2: 3 } },
+        ];
+        expect(getMassBalanceError(singlePhase(concs), phases).error).toBeCloseTo(0, 5);
+    });
+
+    it("error is 0 when both init and final have multiple phases", () => {
+        const initPhases = [
+            { kind: "co2-rich" as const, fraction: 0.8, concentrations: { H2O: 1, NO2: 2 } },
+            { kind: "aqueous" as const, fraction: 0.2, concentrations: { H2O: 1, NO2: 2 } },
+        ];
+        const finalPhases = [
+            { kind: "co2-rich" as const, fraction: 0.5, concentrations: { H2O: 1, NO2: 2 } },
+            { kind: "aqueous" as const, fraction: 0.5, concentrations: { H2O: 1, NO2: 2 } },
+        ];
+        expect(getMassBalanceError(initPhases, finalPhases).error).toBeCloseTo(0, 5);
     });
 });