Forum: aviation.stackexchange.com
Tags: <piston-engine><turboprop>
Title: Is a turbocharged piston aircraft the same thing as turboprop?
Question: Simple question, and I've always assumed that they are the same thing, but I'd like feedback from someone who knows more than me :)

Answers:
sents: text: They are both internal combustion engines that have a turbine in their exhaust that is used to power a compressor to pressurize the air before it is used for combustion.
text: In the turboprop, the turbine also powers the prop.
text: In between the compressor and turbine, the fuel/air mixture is burnt without significant moving parts.
text: Without the turbine and compressor, a turbine engine is essentially a tube with heating element in it.
text: In a turbocharged piston engine, you have an otherwise normal piston engine which turns the prop.
text: The turbine is in the exhaust from the piston engine and powers the compressor pushing air into the piston engine.
text: The turbine and compressor are not connected to the prop though.
text: Here they are as diagrams along with some other types of engine.
answer_details: author: aviation.stackexchange.com/users/3550/smithkm
score: 38
sents: text: No, a turboprop is more like a jet engine with a propeller in the front instead of a fan: Source:
text: Wikimedia
text: In its simplest form a turboprop consists of an intake, compressor, combustor, turbine, and a propelling nozzle.
text: Air is drawn into the intake and compressed by the compressor.
text: Many turbo props have a gear box (as shown in the image above, the black part to the left) which drives the prop from the engine.
text: Whereas a turbo piston is simply a normal piston engine with a turbo charger attached:
text: Source:
text: BoldMethod
text: You can learn more about how a turbo piston works on BoldMethod: How a turbocharger system works .
text: The basics is that it uses the exhaust gases from the engine to drive a compressor which increases the pressure (and oxygen content) going into the intake.
text: More oxygen (and fuel) means more power.
text: For turbo-pistons it also means that you can get sea-level performance at altitude.
text: As far as fuel is concerned, a turboprop runs off of Jet-A (Kerosene) fuels and (most)
text: turbo charged pistons run on av-gas.
text: Some diesel turbo pistons also run off of Jet-A and it is very important that you don't put Jet-A in an av-gas piston or av-gas in a turbo prop.
answer_details: author: aviation.stackexchange.com/users/12623/Ron Beyer
score: 22
sents: text: A turbocharged engine is a common gas engine with pistons
text: The limiting factor on a gas engine is how much air can get into the pistons.
text: It is supercharged - that is, an air pump forces more air into the engine than it would draw naturally.
text: The mechanically driven variety is seen on Mad Max .
text: If you use exhaust flow to spin the pump, it is turbo supercharged.
text: People shorten "turbosupercharge" to "turbocharge".
text: A turboprop engine is a jet engine.
text: Fullstop.
text: The jet engine makes lots of thrust.
text: They stuck some extra turbine blades in the jet blast, which spin another shaft.
text: That makes it a "turboshaft engine" because it makes rotation instead of thrust.
text: You put something useful on that shaft, like a generator , helicopter rotor , naval screw , air compressor , fan , propfan , or in this case, a prop.
text: That's a turboprop!
text: The advantage of a jet-based instead of piston-based engine is power-to-weight - after all you have nominally 2 moving parts, the spindle of the jet engine
text: proper and the added turboshaft, and nothing reciprocates.
answer_details: author: aviation.stackexchange.com/users/22864/Harper - Reinstate Monica
score: 5
sents: text: They are completely different things, a turboprop is similar to a jet engine as it has compressors, the main difference is that there's a shaft that spins a propeller instead of turning a fan.
text: A turbocharger is device for piston engines, it uses pressure coming from the exhaust manifold of a piston engine to compress air going into the intake manifold.
text: It's the same technology used on car diesel and gasoline engines, and it works the same way.
text: There are vanes that can be adjusted to manage the boost level, on cars these are computer controlled but in many airplanes turbo speeds are have to be manually adjusted by adjusting boost pressure in the exhaust (keyword: wastegate).
text: Recent aero-diesels have modern computer controls though.
text: Turbos on piston aero engines can either be turbochargers, in which case they add extra power to an engine by increasing the compression in the cylinders, or they can be turbo-normalizers, which maintain sea level air pressure to the engine even at higher altitudes.
text: There are superchargers as well, these are also compressors for piston engines
text: the difference is they use engine power directly to compress the air rather than exhaust pressure.
answer_details: author: aviation.stackexchange.com/users/1791/GdD
score: 3
sents: text: No, one is https://en.wikipedia.org/wiki/Otto_cycle one is https://en.wikipedia.org/wiki/Brayton_cycle , thermodynamicly extremely different
answer_details: author: aviation.stackexchange.com/users/6854/Sam
score: 2

Summary of the answers:
They are both internal combustion engines, however, they are completely different things, a turboprop is similar to a jet engine as it has compressors, the main difference is that there's a shaft that spins a propeller instead of turning a fan.   
They are both considered internal combustion engines with a turbine in their exhaust that powers a compressor and pressurizes the air before its use in the combustion process. That said, they are totally different things, with turboprop being essentially a jet engine and the main difference being if a shaft is spinning the propeller or a fan.