i am unable to watch recirculations after a bend in a pipe and also secondary flows ,which i have modeled in fluent.I used ske model and 3d segregated solver.please help me what to do ,it is very urgent to me.

Hmm, given your description one can only guess what happened. Please check your grid resolution, maybe you have to refine it in the considered regions. Further you may try to use another turbulence model (rke and skw-sst have worked very well for me). You should have a look at your y+-Value and decide which wall-treatment strategy is suited. My personal choice is to have y+~1-5 and enable enhanced wall treatment. Maybe this works for you too... btw: Even the ske-model should detect the recirculation zone. It is quite weak in predicting the exakt location of seperation and reattachment points regarding channel flow.