This UDF overwrites the blending function in regions where x2:
#include "udf.h" DEFINE_KW_GEKO_BF(user_geko_bf, c, t) { real bf_value; real xc[ND_ND]; C_CENTROID(xc,c,t); if (xc[0]>--> 2.0) bf_value = Get_Geko_Blending_Function (c, t, C_R(c,t), C_MU_L(c,t), C_WALL_DIST(c,t), C_K(c,t), C_O(c,t)); else bf_value = 1.0; return bf_value; }