revise the isothermPosition function in residue.cpp

Makefile

@@ -7,7 +7,7 @@
 compiler	=g++
 CANTERA_DIR	=/opt/scientific/cantera-2.4_gnu_blas
 IDA_DIR		=/opt/scientific/sundials-3.1.1_intel_mkl
-EXE		=DropletCombustion5
+EXE		=DropletCombustion9
 #DESTDIR		=~/bin
 DESTDIR		= ../example
 

main.cpp

@@ -206,7 +206,10 @@ int main(){
 			t1=tNow;
             
             /*Floor small value to zero*/
-            floorSmallValue(data, &y); 
+            floorSmallValue(data, &y);
+            
+            /*reset the tolerance after ignition*/
+            resetTolerance(data,&y,&atolv);
 
 			if(data->quasiSteady){
   				ier = IDASolve(mem, finalTime, &tNow, y, ydot, IDA_ONE_STEP);
@@ -227,14 +230,14 @@ int main(){
   			ier = IDAGetCurrentOrder(mem, &kcur);
 
 			if(data->adaptiveGrid==1 && data->moveGrid==1){
-				x=maxCurvPosition(ydata, data->nt, data->nvar,
-						  data->grid->x, data->npts);
+				//x=maxCurvPosition(ydata, data->nt, data->nvar,
+				//		  data->grid->x, data->npts);
 
 				//x=isothermPosition(ydata, data->isotherm, data->nt, 
 	                	//		   data->nvar, data->grid->x, data->npts);
 
-				//x=maxGradPosition(ydata, data->nt, data->nvar,
-				//		  data->grid->x, data->npts);
+				x=maxGradPosition(ydata, data->nt, data->nvar,
+						  data->grid->x, data->npts);
 				dx=x-xOld;
 
 				if(dx*dxMin>0.0e0){

readme.md

@@ -1,3 +1,5 @@
 Dropletcombustion5 is the version which floor the small mass fraction(smaller than massfractionTolerance) to 0.00 ; 
 Dropletcombustion6 is the version where the Antoine parameters are those of water ;
 Version 7 change the hardcode some tolerance after ignition:Max T> 1800K
+version 8: the x in the main.cpp is changed to the maxGradPosition
+version 9: isothermPosition function in residue.cpp is revised for droplet combustion

residue.cpp

@@ -95,13 +95,28 @@ int maxCurvIndex(const double* y, const size_t nt,
 	return(pos);
 }
 
+//double isothermPosition(const double* y, const double T, const size_t nt, 
+//	                const size_t nvar, const double* x, const size_t nPts){
+//	double pos=x[nPts-1];
+//	size_t j;
+//	for (size_t i = 1; i <nPts; i++) {
+//		j=i*nvar+nt;
+//		if (y[j]<=T) {
+//			pos=x[i];
+//			break;
+//		}
+//	}
+//	return(pos);
+//}
+
+//******************* scan the temperature from left to right ******************//
 double isothermPosition(const double* y, const double T, const size_t nt, 
 	                const size_t nvar, const double* x, const size_t nPts){
-	double pos=x[nPts-1];
+	double pos=x[0];
 	size_t j;
-	for (size_t i = 1; i <nPts; i++) {
+	for (size_t i = 0; i <nPts; i++) {
 		j=i*nvar+nt;
-		if (y[j]<=T) {
+		if (y[j]>=T) {
 			pos=x[i];
 			break;
 		}
@@ -833,7 +848,7 @@ int residue(double t, N_Vector y, N_Vector ydot, N_Vector res, void *user_data){
 	//dHvl= 5.2053e07*pow(1-Tr,0.3199 - 0.212*Tr + 0.25795*Tr*Tr)/18.01;	//J/kg	latent heat of vaporization of water
 	
     double Tr = T(1)/540.2;            //Reduced Temperature:Droplet Temperature divided by critical temperature of liquid n-heptane, Source:NIST
-    dHvl = 5.366e5*exp(-0.2831*Tr) * pow((1-Tr),0.2831);           //Unit:J/kg, latent heat of vaporization of liquid n-heptane, Source: NIST
+    dHvl = 5.366e5*exp(-0.2831*Tr) * pow((1-Tr),0.2831);    //Unit:J/kg, latent heat of vaporization of liquid n-heptane, Source: NIST
     
     /*Following section is related to the property of water*/
     //rhol = 997.0;	
@@ -880,8 +895,8 @@ int residue(double t, N_Vector y, N_Vector ydot, N_Vector res, void *user_data){
     /*Following using the Antoine Parameters to calculate the pressure of volatile component(n-heptane)*/
     //Antoine parameter from NIST website
     double p_i=0.0 ; 
-    p_i = 1.0e5*pow(10,4.02832-(1268.636/(T(1)-56.199))) ;    //FOR N-HEPTANE 
-    //p_i = 1.0e3*pow(2.71828,16.7-(4060.0/(T(1)-37.0)));     //FOR WATER
+    p_i = 1.0e5*pow(10,4.02832-(1268.636/(T(1)-56.199))) ;    //unit:Pa,FOR N-HEPTANE 
+    //p_i = 1.0e3*pow(2.71828,16.7-(4060.0/(T(1)-37.0)));     //Unit:Pa,FOR WATER
     Yres(1,k_drop)=Y(1,k_drop) - p_i * data->gas->molecularWeight(k_drop-1) 
 				    / P(1) / data->gas->meanMolecularWeight();
 	
@@ -1553,3 +1568,50 @@ void floorSmallValue(UserData data, N_Vector* y)
     
 
 }
+
+void resetTolerance(UserData data, N_Vector* y,N_Vector* atolv)
+{
+    double* ydata;
+    realtype* atolvdata; 
+    ydata = N_VGetArrayPointer_OpenMP(*y);
+    atolvdata = N_VGetArrayPointer_OpenMP(*atolv);
+    double relTol,radTol,tempTol,presTol,massFracTol,bathGasTol,mdotTol;
+    double maxT=0.00, ignT=1800;
+    relTol = 1.0e-03 ; 
+    radTol = 1.0e-05 ; 
+    tempTol = 1.0e-01 ; 
+    presTol = 1.0e00 ; 
+    massFracTol = 1.0e-08; 
+    bathGasTol = 1.0e-04 ; 
+    mdotTol = 1.0e-09 ; 
+
+
+    /*Get the maximum Tempture*/
+    for (size_t i =1;i <= data->npts;i++){
+        if(T(i) > maxT){
+            maxT = T(i);
+        }
+    }
+
+    /*reset the tolerance when maxT > ignT*/
+    if(maxT >= ignT){
+        data->relativeTolerance = relTol;
+
+        for(size_t i =1; i<=data->npts; i++){
+            atolT(i) = tempTol; 
+            atolR(i) = radTol ; 
+            atolP(i) = presTol ;
+            atolMdot(i) = mdotTol ; 
+            
+            for(size_t k =1; k<= data->nsp; k++){
+                if(k!=data->k_bath){
+                    atolY(i,k) = massFracTol;
+                }else{
+                    atolY(i,k) = bathGasTol;
+                }
+            }
+        }
+    }
+
+}
+

residue.h

@@ -93,3 +93,4 @@ void getTimescale(UserData data, N_Vector* y);
 void printTimescaleHeader(UserData data);
 void printTimescaleOutput(double t,N_Vector* y,FILE* output,UserData data);
 void floorSmallValue(UserData data, N_Vector* y);
+void resetTolerance(UserData data, N_Vector* y,N_Vector* atolv);