FLUENT学习udf编程实例.pdf

/************************************************** UDF：通过规定一个依赖于温度的粘性特性来模拟凝固 ********************************************/ #includeudf.h DEFILE_PROPERTY(cell_viscosity,cell,thread) { real mu_lam; real temp=C_T(cell,thread); if(temp288.) mu_lam=5.5e-3; esle if(temp286.) mu_lam=143.2135-0.49725*temp; else mu_lam=1.; return mu_lam; } #includeudf.h #includemath.h DEFINE_CG_MOTION(velocity,dt,vel,omega,time,dtime) {real t=RP_Get_Real(flow-time); int n; float c; n=t/25; c=t-n*25; omega[0]=0; omega[1]=0; omega[2]=0; if (c=0c=10) vel[0]=0; vel[1]=0; vel[2]=0.2; else if (c10.0c=15.0) vel[0]=-0.1; vel[1]=0; vel[2]=0; else vel[0]=0; vel[1]=0; vel[2]=-0.2; } /******************************************************** 计算气浊率的UDF *******************************************************/ #includeudf.h #define MIN_VOF 1.e-5 #define MAX_VOF 0.999999 DEFINE_CAVITATION_RATE(user_cavitation_rate,c,t,p,rhoV, rhoL,vofV,p_v,n_b,m_dot) { real p_vapor=*p_v; real n_bubbles=*n_b; real dp,vofM,radV; dp=p_vapor-ABS_P(p[c],op_pres); vofM=MIX(MAX(MIN_VOF,vofV[c],MAX_VOF)); radV=pow(vofM/((1.-vofM)*4./3.*M_PI*N_Bbubbles),1./3.); if(dp0) *m_dot=(1.-vofV[c])*n_bubbles84.*M_PI*radV* radV/(1.*n_bubbles*4./3.*M_PI*radV*radV*radV)* sqrt(2.*ABS(dp)/(3.*rhoL[c])); else { *m_dot=-(1.vofV[c])*n_bubbles*4.M_PI*radV* radV/(1.*n_bubbles*4./3.M_PI*radV*radV*radV)* sqrt(2.*ABS(dp)/(3.*rhoL[c])); if(vofV[c]=MIN_VOF)*m_dot=0.; } } /****************************************************** 关于演示DEFINE_CHEM_STEP的UDF的例子 *******************************************************/ #includeudf.h DEFINE_CHEM_STEP(user_chem_step,ifail,n,dt,p,temp,yk) { int i; real c=1./n_spe,decay=exp(-dt); for(i=0;ispe;i++) yk[i]=(yk[i]-c)*decay+c; } /**