Hello, Mr. Zeineldin Elserfy

I may not be able to clearly remember my Matlab coding for calculating displacement thickness and momentum thickness of a transonic gas flow in a small chamber I made several years ago. But the main steps might be helpful:

1. I got the necessary data on a side wall from CFD, such as x, y, density, pressure, Mach number, temperature. My task was to figure out the two thicknesses on that wall.

2. I calculated the thickness values at each x-location (one by one using 'for' syntax) by integrating the equations in y direction.

3. I used spline function to link all the thickness values along x-location, and finally I got the smooth curves along x-direction (chamber length) which are the displacement and momentum thicknesses.

It might sound naive, but hope you would make it soon!

Han

Japan

Dear Zein

I hope you are doing well.

what you suggested is fine and Dr Han approach is very typical

Good luck

Osama

-Dr Bing Han, thanks for your reply. I was thinking of doing it exactly as you mentioned, but do you remember how you calculate the displacement or momentum thickness at each x-location? you plot the data point (velocity,y) and then curve fitting to predict equation for the velocity profile and finally integrate the equation predicted by curve fitting? am I right?

-Dr Joana Rocha, thanks for your reply. can you please resend the link again as it is not working?

-Dr Osama Ahmed Elsamni, I am fine and I hope you are doing well. Thanks for your help and reply.

Joana Rocha thanks for your reply. I really appreciate it.

Dear Zeineldin Elserfy , sorry for the late reply, did you make it already? If the curve fitting for velocity profile is complex, you can just accumulate the equation values in y-direction for each x location if your mesh is fine enough, instead of using curve fitting and integration.

If the boundary layer is stably developed, you are supposed to eventually get a smooth curve for the thicknesses. Good luck! :)