Method to divide collisions from a collisional iteration into multiple

pushing iterations.

src/modules/mesh/moduleMesh.f90

@@ -379,7 +379,7 @@ MODULE moduleMesh
     END SUBROUTINE findCell
 
     !Computes collisions in element
-    SUBROUTINE collision(self)
+    SUBROUTINE collision(self, t)
       USE moduleCollisions
       USE moduleSpecies
       USE moduleList
@@ -388,8 +388,12 @@ MODULE moduleMesh
       IMPLICIT NONE
 
       CLASS(meshVol), INTENT(inout):: self
+      INTEGER, INTENT(in):: t
+      INTEGER:: modCollisions !Remain of current iteration and everyCollisions
+      INTEGER:: iterToCollisions !Number of iterations from current to next collision
       INTEGER:: nPart !Number of particles inside the cell
       REAL(8):: pMax !Maximum probability of collision
+      INTEGER:: nCollIter !Number of collisions to be computed in this iteration
       INTEGER:: rnd !random index
       TYPE(particle), POINTER:: part_i, part_j
       INTEGER:: n !collision
@@ -397,19 +401,36 @@ MODULE moduleMesh
       REAL(8):: sigmaVrelMaxNew
       TYPE(pointerArray), ALLOCATABLE:: partTemp(:)
 
-      self%nColl = 0
+      modCollisions = MOD(t, everyCollisions)
+      iterToCollisions = everyCollisions - modCollisions
+
       nPart = self%listPart_in%amount
       IF (nPart > 1) THEN
-        pMax = self%totalWeight*self%sigmaVrelMax*tauCollisions/self%volume
-        self%nColl = INT(REAL(nPart)*pMax*0.5D0)
-
-        !Converts the list of particles to an array for easy access
-        IF (self%nColl > 0) THEN
-          partTemp = self%listPart_in%convert2Array()
+        IF (modCollisions == 0) THEN
+          !Collisional iteration, computes the number of iterations
+          pMax = self%totalWeight*self%sigmaVrelMax*tauCollisions/self%volume
+          self%nColl = INT(REAL(nPart)*pMax*0.5D0)
 
         END IF
 
-        DO n = 1, self%nColl
+        IF (self%nColl > iterToCollisions) THEN
+          nCollIter = self%nColl / iterToCollisions
+
+        ELSE
+          nCollIter = self%nColl
+
+        END IF
+
+        IF (nCollIter > 0) THEN
+          !Converts the list of particles to an array for easy access
+          partTemp = self%listPart_in%convert2Array()
+
+          !Removes collisions from this iteration form the total in the cell
+          self%nColl = self%nColl - nCollIter
+
+        END IF
+
+        DO n = 1, nCollIter
           !Select random numbers
           rnd = random(1, nPart)
           part_i => partTemp(rnd)%part
@@ -429,11 +450,8 @@ MODULE moduleMesh
           END IF
             
         END DO
-
       END IF
 
-      self%totalWeight = 0.D0
-
     END SUBROUTINE collision
 
     SUBROUTINE printOutputGmsh(self, t)