New argument added in the turbulent conductivity macro C_K_T for 6.1
Fluent6.0 turbulent conductivity macro used 2 arguments : C_K_T(c,t) Fluent6.1 turbulent condcutivity macro uses 3 arguments : C_K_T(c,t,prt) How to define this new argument to obtain the same thing in 6.1 than in 6.0 ? Some changes in the turbulent Prandtl number definition have been done between fluent 6.0 and 6.1 With fluent 6.1, you can now define kepsilon and komega model constants by UDF macro (DEFINE_PRANDTL) : TKE prandtl number, TDR prandtl number, Energy prandtl number and Wall prandtl number In 6.1 version, the turbulent conductivity could be define as a fonction of the prandtl number (= "Energy prandtl number") defined by udf. It's the reason why a new argument has been added in the C_K_T macro. To obtain in fluent 6.1 the same turbulent conductivity formulation than in 6.0 (with a constant "Energy prandtl number"), you must define your turbulent conductivity with the "M_keprt" fluent variable. C_K_T(c,t) in 6.0 becomes C_K_T(c,t,M_keprt) in 6.1. In kepsilon and komega model, M_keprt default constant value is 0.85 ... 

