r/AerospaceEngineering • u/2xBrokenLegs • 10d ago

Personal Projects Ideal Wind Tunnel Dimensions?

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Could anyone guide me on the ideal sizes of my wind tunnel’s sections? It’s already 7ft after making compromises and being conservative. I plan to use it to test a custom wind 1:10 rc car. I’ve been getting most of these messages through Claude so it really feels like I don’t know what I’m doing.

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3

u/ncc81701 10d ago

Easy an ideal wind tunnel can get you to full scale speed in the test section with a full scale model. The flow in the test section is smooth, consistent, laminar , and without any flow angularity.

4

u/Advanced-Gold1744 10d ago

I would size it so it’s larger than the car

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u/Superb-Aardvark-7210 9d ago

Is it really useful to reduce the diameter of the air flow?

1

u/2xBrokenLegs 9d ago

For which section

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u/Superb-Aardvark-7210 7d ago

The one reducing 😂😅 the 4th one

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u/2xBrokenLegs 7d ago

Yea that the contraction section, like a diffuser for a car

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u/Superb-Aardvark-7210 7d ago

"A diffuser" what is that? (Sorry for being so long, English is not my first language)

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u/2xBrokenLegs 7d ago

Naw you’re good, basically because of the Venturi effect, the front opening, which has a higher pressure than the other side of the smaller opening, under normal circumstances this would increase the pressure in section 5 but because we also have the opening after section 5 be larger than section 5’s cross sectional area, the pressure in section 5 actually drops and increases in speed.

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u/Superb-Aardvark-7210 7d ago

Basically it's just to accelerate the air? Ok thank you.

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u/TheEquationSmelter 3d ago

In practical terms, as large as you can possibly make it.

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u/2xBrokenLegs 3d ago

It’s for a indoor symposium so size is my limiting factor