In cases where a separate velocity field is specified for different fluids, clicking "Generate Values" on the profile boundary condition form does not automatically enter the velocity profile. You must do this manually, by entering an expression. For example: myprofile.Velocity u(x,y,z) can be entered for the velocity, where "myprofile" is the name of the profile, and "Velocity u" is the name of the U Velocity variable in your profile data file.