Bug fixed - Wall reaction coefficient variable in water quality simulation is explicitly defined and added since epanet uses the roughness resistance variable as it and caused some error in step wise calculation.

src/quality.c

@@ -1458,7 +1458,7 @@ void  ratecoeffs()
    {
       kw = Link[k].Kw;
       if (kw != 0.0) kw = piperate(k);
-      Link[k].R = kw;
+      Link[k].Rc = kw;
       R[k] = 0.0;
    }
 }                         /* End of ratecoeffs */
@@ -1541,7 +1541,7 @@ double  pipereact(int k, double c, double v, long dt)
 
    /* Otherwise find bulk & wall reaction rates */
    rbulk = bulkrate(c,Link[k].Kb,BulkOrder)*Bucf;
-   rwall = wallrate(c,Link[k].Diam,Link[k].Kw,Link[k].R);
+   rwall = wallrate(c,Link[k].Diam,Link[k].Kw,Link[k].Rc);
 
    /* Find change in concentration over timestep */
    dcbulk = rbulk*(double)dt;

src/types.h

@@ -208,6 +208,7 @@ typedef struct            /* LINK OBJECT */
    double  Kb;             /* Bulk react. coeff */
    double  Kw;             /* Wall react. coeff */
    double  R;              /* Flow resistance   */
+   double  Rc;             /* Reaction cal      */ //woohn 2/11/13
    char    Type;           /* Link type         */
    char    Stat;           /* Initial status    */
    char    Rpt;            /* Reporting flag    */