激光焊接 FLUENT UDF 热源模型 能量源项 动量源项 define

#include "udf.h" DEFINE_INIT(my_init, d)/*初始化温度场 Set temperature on specified region*/ { cell_t c; Thread* t; real xc[ND_ND]; thread_loop_c(t, d) /*Loop over all threads in domain*/ { begin_c_loop(c, t) { C_CENTROID(xc, c, t); if (sqrt(ND_SUM(pow(xc[0] - 0.5, 2.), pow(xc[1] - 0.5, 2.), pow(xc[2] - 0.5, 2.))) < 0.25)/*判断距离*/ C_T(c, t) = 500.; else C_T(c, t) = 300.; } end_c_loop(c, t); } } DEFINE_ADJUST(my_adjust, d) /*calculate volume integral of turbulent dissipation*/ { cell_t c; Thread* t; real sum_diss = 0; /*integrate turbulent dissipation */ thread_loop_c(t, d) { begin_c_loop(c, t) { sum_diss += C_D(c, t) * C_VOLUME(c, t);/*C_D turbulent dissipation*/ } end_c_loop(c, t); } Message("Volume integral of turbulent dissipation: %g\n", sum_diss); } DEFINE_DELTAT(my_timestep, d) /*change time step depending on flow time*/ /*unsteady only*/ /*access:Iteration Panel*/ { real time_step; real flow_time = RP_Get_Real("flow-time"); /*后一项为fluent求解器提供的宏，用于得到当前时间*/ if (flow_time < 0.5) time_step = 0.1; else time_step = 0.2; return time_step; } DEFINE_PROFILE(my_velocity, t, i) /*ux(t)=U0+Asin(wt)*/ /*循环*/ { face_t f; real flow_t; /*to hold current flow time*/ real u; flow_t = RP_Get_Real("flow-time"); begin_f_loop(f, t) { u = 20. + 5. * sin(10. * flow_t); F_PROFILE(f, t, i) = u; } end_f_loop(f, t); } DEFINE_SOURCE(X_momentum, c, t, dS, eqn) /*S=-0.5ρyVx2 dS/dVx=-ρyVx */ /*无需循环*/ { real x[ND_ND], ws, source; C_CENTRORID(x, c, t); ws = 0.5 * C_R(c, t) * x[1]; /*C_R(c,t)密度*/ source = -ws * C_U(c, t) * C_U(c, t); ds[eqn] = -2 * ws * C_U(c, t); return source; } DEFINE_PROPERTY(my_property, c, t) /*laminar viscosity as function of temperature*/ /*无需循环*/ { real mu_lam, temp = C_T(c, t); if (temp > 288.) mu_lam = 5.5e-3; else if (temp > 286.) mu_lam = 143, 2135 - 0.49725 * temp; else mu_lam = 1.; return mu_lam; } DEFINE_UDF_FLUX(my_flux, f, t, ns) /*return user specified flux*/ { real J[ND_ND], A[ND_ND], flux; NV_D(J, =, F_U(f, t), F_V(f, t), F_W(f, t)); NV_S(J, *=, F_R(f, t)); F_AREA(A, f, t);/*get area vector*/ flux = NV_DOT(J, A); /*NV_D,NV_S,NV_DOT,F_AREA are FLUENT macros*/ return flux; }