Hi. In define source model we have such statement:

DEFINE_SOURCE(enrg_src, cell, mix_th, dS, eqn)

What is dS and eqn responsible for?

How this affect on energy source (code below)?

DEFINE_SOURCE(enrg_src, cell, mix_th, dS, eqn) { Thread *pri_th, *sec_th; real m_dot; real T_SAT = 100; real lambda1 = 1; real lambda2 = 1; real q = 1000;

pri_th = THREAD_SUB_THREAD(mix_th, 0); sec_th = THREAD_SUB_THREAD(mix_th, 1);

if(C_T(cell, mix_th)>=T_SAT) {

m_dot = -(12* lambda1 * (fabs(C_T(cell,sec_th)-T_SAT)) * 1)/q;

dS[eqn] = -(12* lambda1 * 1)/q;}

else {

m_dot =(12* lambda2 * (fabs(C_T(cell,pri_th)-T_SAT)) * 1)/q;

dS[eqn] = (12* lambdaH2O * 1)/q;}

thank you for help

The dS[eqn] function is used to linearise the source term to make the solution more stable. It doesnt change the final solution, it just guides it in the right direction. You can find a more detailed explanation on the CFD Wiki at http://www.cfd-online.com/Wiki/Sourc..._linearization

thanks for help