For an aerofoil study, my pressure and velocity profiles are correct, but my skin friction plots are very wrong.

I am using the k-epsilon model and I am not sure about the wall functions I am using.

Can anyone suggest why the skin friction may be so inaccurate for this transonic tubulent model.

(1). That is the first thing you should know before you start using the commercial codes. (2). In general, it is very hard to get accurate wall quantities, such as the skin friction and the heat transfer, unless you are doing your own turbulence modeling and validation, assuming that you know what to do with the grid. (3). Ready to do your own research? (I mean, it's not there yet, unless you are the expert.)