BUG: InjectionModelList: avoid an FPE instance while using spray cloud (fixes #3413)

src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/InjectionModel/InjectionModelList.C

@@ -163,7 +163,7 @@ Foam::scalar Foam::InjectionModelList<CloudType>::averageParcelMass()
         massTotal += mt;
     }
 
-    return mass/massTotal;
+    return mass/stabilise(massTotal, SMALL);
 }
 
 

src/lagrangian/intermediate/submodels/Kinematic/InjectionModel/PatchFlowRateInjection/PatchFlowRateInjection.C

@@ -79,6 +79,8 @@ Foam::PatchFlowRateInjection<CloudType>::PatchFlowRateInjection
     // - will be reset during each injection
     this->volumeTotal_ = 0.0;
     this->massTotal_ = 0.0;
+
+    volumeToInject(time.value(), time.value() + duration_);
 }