An aircraft exhaust system is highly significant for flight safety. Defective exhaust assemblies can result in loss of engine performance, carbon monoxide poisoning and even fire. It’s vital to ensure regular inspection and maintenance of these exhaust systems to keep them in optimum condition.
An airplane’s engine, jet, or piston is just an air pump - it’s primary function is to take air in and compress it. When fuel is added, and subsequent ignition occurs afterward, the expanded air gets to jet out the back or is pushed down a piston. So, how does a plane’s exhaust system influence its engine performance?
A well-cleaned and well-maintained aircraft exhaust mechanism not only makes the engine perform at its peak efficiency and power but also significantly contributes to the overall secure and efficient airplane operation.
Pressure Ratios And Aircraft Exhaust System
Pressure ratios refer to both power and efficiency. This means that the higher the pressure ratio, the better the performance of the aircraft engine. Of course, other factors like engine weight and size, and the amount of fuel consumption during a flight also come into play.
So, can the current state and integrity of an aircraft exhaust system have any effect on pressure ratios? The answer is, yes. Any obstruction present in the hot air exit from an engine leads to a reduction in the pressure ratio, affecting the efficiency and power of the engine.
Understanding Aircraft Exhaust Systems Functionality
Unlike simpler vehicle exhaust systems, airplane exhaust systems carry out two significant functions. First, they help in venting exhaust gases away from the fuselage and engine while decreasing noise. Second, they also indirectly supply carburetor and cabin heat.
Aircraft exhaust systems are consistently exposed to increased temperatures ranging from 1200 to 1400 degrees Fahrenheit. Also, hydrocarbon fuels continually burn throughout these exhaust assemblies, leaving corrosive leftovers that can build up and damage significant components of exhaust systems. For this reason, qualified aircraft maintenance technicians pay much attention to possible signs of more-than-usual deterioration or even obstructions during exhaust and engine inspections.
Defective exhaust systems not only result in poor engine performance, but also enhance the possibility of hazards like carbon monoxide poisoning, fire, or any other mishaps form potential system leaks. In piston-based aircraft engines, there are mainly two kinds of exhaust systems:
- Short stack system is the type of exhaust system that’s usually utilized on low-powered engines and non-supercharged engines in which there’s not too much noise
- Collector system is the type of exhaust system that’s mostly utilized on all turbo supercharged engines and installations and larger non-supercharged engines. It helps in improving nacelle streamlining and also aids in easier maintenance in the nacelle portion
When it comes to turbo supercharged engines, the exhaust gases are collected to drive the supercharger’s turbine compressor. Both systems are made with exhaust headers that help in expelling hot exhaust gases into a standard collector ring having a single outlet. As a result, the combustion gases are vented via a tailpipe into the supercharger, hence driving the turbine.
At high altitudes with much lesser air density than on the ground, many aircrafts utilize highly compressed fuel and air mixtures for engines to provide increased efficiency. A turbocharger or supercharger is used to compress the incoming air before it gets injected into the engine section. A turbocharger is like an air compressor, having rotating blades utilizing the exhaust from the engine.
Due to this, maximum engine functionality largely depends on the quality of the exhaust system. That’s why modern-day aviation best practices emphasize on using cleaner exhaust systems to enhance engine performance and efficiency further.