what are advantage/ disadvantage of many fan blades vs 3 or 4 blades…? and why does my desk fans usually have 3 blades as oppose to many small blades like a turbo fan engine fan disk?
In: Engineering
A regular propeller is just pushing air backwards. A jet engine is not only pushing air but also also gathering and compressing it, to be able to burn fuel in that denser air and push hot burned gas out the back at much higher speed or spin an engine shaft. The higher pressure needs more blades.
Oddly, in aircraft, it’s common to use one of these jet engines to power a propeller (turboprop) but it’s only practical there because there’s so much air available to the engine intakes. You couldn’t do this in a car for example to power the wheels. (There are some weird jet concept car exceptions but they weren’t very efficient).
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