[awacs]

Dear foamers,

I'd like to create a piecewise viscosity model described as following:

(1) when T<Tg, viscosity is equal to a constant:

nu = nu0;

(2) when T>=Tg, viscosity varies with temperature, pressure and strain rate:

nu= (B_*exp(B1_*pd)*exp(Tb_/T))/(RHO_*(scalar(1)+pow((B_*exp(B1_*pd)*exp(Tb_/T))*strainRate()/t1_, scalar(1)-n_)));

where B, B1, Tb, t1, n are material constants.

How to define this piecewise function in calcNu() in user-defined viscosity model?

Best regards,
Jitao