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-   -   Energy equation in boiling of water (http://www.cfd-online.com/Forums/fluent/43805-energy-equation-boiling-water.html)

greg February 19, 2007 03:43

Energy equation in boiling of water
 
coul you please check my energy equation from boiling process? Something is no good with it because after few 000 of iterations temperature reach 5000K (what is upper limit of temperature). In my case max. temperature is 500K (heating medium).

DEFINE_SOURCE(enrg_src, cell, mix_th, dS, eqn) { Thread *pri_th, *sec_th; real m_dot; real T_SAT = 373; real lambdaLiBr = 0.438; /* W/mK */ real lambdaH2O = 0.078; /* W/mK */ /* lambda vapour */ real qdes = 2772; /* vaporization heat*/ /* kJ/kg */ 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* lambdaLiBr * (fabs(C_T(cell,sec_th)-T_SAT)) * 1)/qdes;

dS[eqn] = -(12* lambdaLiBr * 1)/qdes;

}

else {

m_dot =(12* lambdaH2O * (fabs(C_T(cell,pri_th)-T_SAT)) * 1)/qdes;

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

} return qdes*m_dot; }

thanks for help.


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