AboutPaul Soderman Expertise Aeronautics, Fluid Mechanics, Aeroacoustics, Noise Control, Muffler Design, Wind Tunnel Research.... I know nothing about India - do not ask about schools, jobs, application requirements, career choices, etc. for India. Please, no text message verbiage; I prefer full words in full sentences. Thanks.
Experience 38 years as research engineer at NASA
Publications AIAA, NASA
Education/Credentials B.S. and M.S. Aeronautical Engineering - U. of Washington
Graduate work Standford U.
Awards and Honors AIAA Associate Fellow (American Institute of Aeronautics and Astronautics)
My background has been the design and build of simple automated machinery .
I been instructed to build a wind tunnel .
Having looked around on the web , there is alot of stuff I don't understand , especially formulas . My education is high school level .
Would it be possible to get your opinion of this cross section ? I'm open to any changes you might suggest .
Regards
Greg
Answer Greg
You have a good contraction ratio for a subsonic wind tunnel. The length of contraction should be as short as practical. For the test section, an octagonal or circular test section is better than a square or rectangular test section because of the flow in the corners. Here is advice on the contraction from my friend Ken Mort:
"The shape should be an S shape with cubics at each end. The inflection point should be much closer (1/4-1/3 of the length) to the inlet than the exit. I like the guides given in the following.
Rouse, Hunter and Hassan, M. M.: "Cavitation-Free Inlets and Contractions". Mechanical Engineering, Vol. 71, March 1949, pp 213-216.
The same guides are also given in NASA TN D-8243."
It would also help to get the following book: Low-Speed Wind Tunnel Testing by W. Rae and A. Pope. You need to read about diffusers, corner vanes, drive fans, etc.
Paul