Increasing Propeller Engine Performance at Higher Altitudes.

Altitude believe it or not has a huge affect on how the aircraft engine performs. How you might ask? Well it is because the less dense and cooler the outside air is, the more efficient these turbine engines become. Propeller engines are the opposite, they do not perform well at higher altitudes because of their construction and operating flaws, which I will go into shortly. Airflow is the biggest factor in engine performance, this is why these Turbine engines need a ton of good airflow for combustion as well as for secondary air used in cooling the engines internals as well as aircraft systems. 

Now you would not want to try and fly a turbo prop aircraft at higher altitudes because they are not as efficient as their turbine engine counterparts."The piston or reciprocating engine, with all of its moving parts, must convert the thermal energy into mechanical energy and then finally into thrust by rotating a propeller." (FAA, n.d.) I think that the way to improve efficiency for Turboprop engines at high altitude would be to convert or upgrade some of the engine technology to match that of the Turbine engine applications. Primarily I would incorporate a bigger Core Compressor that can efficiently convert airflow into compressed air more effectively to increase thrust. Another thing I would do would be to add a fan type propeller system like you would see on a high bypass turbo fan engine with around 12-20 blades as opposed to 5 or 6 like you would normally see. This can allow you to get more thrust efficiency from your engine because you are not relying on blade angle and manifold pressure to gain your power. Alternatively, doing this would get rid of that factor and you could focus on improving internal components that will let you gain your thrust and power through pure RPM and ITT (Internal Turbine Temperature). That is where the bigger, more efficient Core comes into play, as well as using better materials in your High Pressure Compressor such as Ceramic blades that maintain a more cooler temperature which aids in engine performance and power.  Along with that, I would add a more efficient heat exchanger that would effectively cool the fuel and heat the oil better at these higher altitudes to prevent the fuel from developing ice crystals in the system. Finally, being able to upgrade some of the components and systems will allow you to fly longer distances with less stress on the engine because of the cooler, less dense air that is used at much higher altitudes, which increases the overall thermal efficiency of the engine. The only issue with flying at such increased altitudes is the reduction in ability to maneuver, so it is always smarter to find a good middle ground where you have some maneuverability as well as engine performance. What are your thoughts? And what would you do to improve something like this? 

Source:

FAA.gov, n.d. Transition to Jet-Powered Airplanes. Federal Aviation Administration. Retrieved from: Transition to Jet-Powered Airplanes - Federal Aviation Administrationhttps://www.faa.gov › aviation › media › 17_afh_ch15