would u please explain to me or correct me how to plot XY plot of inlet velocity parabolic profile using FLUENT UDF example code at UDF manual .i use this code at fluent UDF manual but it doesn't give prabolic profile please help me if u have idea thanks in advance siht

You want to plot the velocity profile or you want to define the parabolic velocity profile at the inlet. If you want to just plot the velocity, UDF is not needed

i want to plot the inlet velocity for rectangular geometry and iam using 2D face . thanks

Velocity profile at entrance will not be parabolic. After some entry lenght it will be. To see this use following steps:

(i)create some lines parallel to the inlet using surfaces-line (ii)Plot- xy plot deselect 'position on x-axis' y-axis function: grid-y x-axis function: velocity surfaces: created lines plot

i mean when iam using UDF to customize the inlet velocity (parabolic velocity)for rectangular geometry thanks