My Reynolds is about 600,000. The case is a simple cantilever wing in a free flow domain with a flow of 50m/s. Rans model is Realizable Ke with standard wall functions and y+ > 30. I'm using a first order coupled solver, Pressure based and transient. Timestep of 0.002s My main problem is that the setup works fine if I run it at 50m/s constant speed in the inlet velocity field. The problem arises when I try to include the udf to ramp the velocity.

Thanks for you help.