Turbulence HELP?

Question

Guys pls help me on this. do wind turbulence have effect on lift. The funnel shape of a wind tunnel do produce wind turbulence right? I tried to follow the design for my research and the air velocity across is like 9-3ms^-1(high range). so how the test models in the wind tunnels can get accurate results. Pls explain to me. Correct me if i am wrong.

Answer 1

Yes, turbulence in your tunnel will affect your test results. It sounds like you've got a low speed wind tunnel - 9.3 m/s - which is around 30 ft/second - 25mph - is this correct? As long as you've got a smooth flow - check with smoke - at your test section, you should be okay. Your best bet is finding other research institutions working at similar reynolds numbers and talk to them about their findings with turbulence. How far upstream is your flow straightener, etc... - these all have a major affect on your results.

Answer 2

The funnel shape or nozzle section of the WT shouldnt have any turbulence so long as you keep the reynolds numbers low for your test. at 9.3 m/s you may not have a problem assuming the nozzle section isnt too narrow.

I presume the tunnel is open ended.  It doesnt loop back around?  if so, you can increase the total presure in the chamber and lower the reynolds no. and turbulence as well as increase the total air mass flow.

If this still isnt enough, you could try a water tunnel. using a smaller scale and slower flow you can (with similitude) determine the same parameters with very low flowrates.

wer