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Turbocharger power input (consumption)
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SilverSolder:

--- Quote from: unknownparticle on March 25, 2020, 04:57:14 pm ---Had to find that guys name!!  Nick Mann, heres his website with full details :-

https://raceenginedesign.co.uk/the-manic-beattie/

Really interesting if you're a petrol head.

--- End quote ---

Batshit crazy.  Love it!  :D
Circlotron:
Okay, back to the original topic.
Let’s try it again for a 3 litre engine at 6000rpm with 15 psig. Instead of a turbo, say our compressor is a very long cylinder and piston with a cross sectional area of 1/15 square inch. That means this piston needs 1 pound force against 15 psi. The engine will consume 9000 litres per minute of air, but at double normal density. 9,000,000,000 cubic mm. The piston in our long compressor cylinder has a surface area of 1/15 sq  inch or 43 sq mm so to displace 9G cubic mm per minute it would move at 9G/43 = 209,302,325 mm per minute or 686,687 feet per minute, against 1 pound force, so 686,687 foot pounds per minute. 686,687/33,000 = 20.8hp = 15.52kW. That’s pretty simplistic, but it’s a starting point.
james_s:
The whole point of a turbocharger is that it recovers otherwise wasted energy from the exhaust and uses that to drive the compressor wheel that supercharges the engine. If you want to know how much energy that takes, you'd likely have more luck looking at engine driven superchargers as the parasitic load they draw is likely to be better documented.

I don't know how well it translates to car sized engines but I recall reading that the supercharger used on the RR Merlin aircraft engine draws about 500HP from the crankshaft so the ~1300HP engine was actually producing closer to 1800HP. A mechanically driven supercharger is simpler, easier to build and cheaper but the fact that a turbocharger uses mostly otherwise wasted energy makes it significantly more efficient.
james_s:

--- Quote from: Someone on March 26, 2020, 12:18:01 am ---https://en.wikipedia.org/wiki/Antilag_system

--- End quote ---

I actually kind of like the lag in my old Volvo, that kick in the pants when the turbo finally spools up is a lot of fun, it's like the whole car suddenly wakes up and leaps forward.
langwadt:

--- Quote from: Circlotron on March 26, 2020, 09:52:50 pm ---Okay, back to the original topic.
Let’s try it again for a 3 litre engine at 6000rpm with 15 psig. Instead of a turbo, say our compressor is a very long cylinder and piston with a cross sectional area of 1/15 square inch. That means this piston needs 1 pound force against 15 psi. The engine will consume 9000 litres per minute of air, but at double normal density. 9,000,000,000 cubic mm. The piston in our long compressor cylinder has a surface area of 1/15 sq  inch or 43 sq mm so to displace 9G cubic mm per minute it would move at 9G/43 = 209,302,325 mm per minute or 686,687 feet per minute, against 1 pound force, so 686,687 foot pounds per minute. 686,687/33,000 = 20.8hp = 15.52kW. That’s pretty simplistic, but it’s a starting point.

--- End quote ---

it is a starting point, some of the pressure would come from the increase in temperature

https://checalc.com/calc/compress.html

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