Aircraft Engine Cooling Systems

Whether one is operating an aircraft with a turbine or reciprocating engine, excessive heat can prove very detrimental to the overall health and functionality of internal combustion engines. With consistent ignition of fuel and air mixtures and large amounts of extremely hot exhaust gases being forced through systems, cooling is crucial to avoid damaging parts or a complete engine failure. Through the use of air cooling, liquid cooling, heat exchangers, and other methods, aircraft engines can be protected and maintained over numerous flight operations.

With all internal combustion engines, chemical energy from fuel can be transformed into mechanical energy that allows for propulsion generation and flight. With the combustion of fuel and air mixtures, resulting exhaust gases need to be removed as quickly as possible due to their effect on combustion, engine part service lives, and lubrication. For example, overheating can lead to the preheating of fuel and air mixtures, causing early combustion which may result in detonation, knocking, and other damages. As such, having an efficient engine cooling system for an aircraft is crucial for its safety.

Regarding reciprocating engines, both air and liquid cooling may be used, though air cooling serves as the most common method for a majority of models. During standard engine operations, about half of the resulting heat is expelled from the system as exhaust. The other half, on the other hand, is absorbed by surrounding engine components, and lubricating oil is used to soak up heat and remove it by transferring it to the airstream. While air cooling will typically consist of removing heat from the cylinders into the air, cylinders can be large components that cannot be fully placed in the airstream. Instead, the engine cooling system takes advantage of cooling fins and related components to increase radiation heat transfer and avoid hotspots.

With components known as cowling and baffles, more air can be forced over the cooling fins. Through baffles, air is specifically pushed around cylinders to prevent any areas from having stagnant air which can lead to increased heating. With the addition of blast tubes, cooling air can be launched into rear spark plug elbows for reducing temperatures, thus improving ignition lead operations. Lastly, augmentors are useful for cooling a number of systems, and such assemblies feature tubes to collect exhaust heat for defrosting, anti-icing systems, and for heating the cabin. While cooling is very important to any combustion engine, one should always ensure that the engine is not over-cooled as performance can suffer as well. With cowl flaps, cooling can be controlled through jackscrews, hydraulic actuators, or by manual means.

For turbine engines, the construction of the apparatus requires cool air to enter the system internally. With large amounts of airflow, hot sections of the engine can have their heat cut down to a range of 1,500 to 2,100 degrees Fahrenheit. As exhaust gases push their way towards the turbine, some heat may already be dissipated, and a large amount of remaining heat is conducted to the outside skin of the aircraft due to its metal casings. Through secondary air passages and cooling-air inlets, combustion chamber liners, bearings, the turbine case, and the turbine nozzle can all be significantly cooled. With the addition of exhaust expulsion, insulation blankets, and other such cooling methods, the rest of the engine’s excessive heat can be removed or dissipated.

For combustion engines that utilize liquid cooling, such engine cooling systems will often rely on water jackets. With water jackets encapsulating cylinders, liquid coolant circulates around the engine components and absorbs heat. Through the use of a heat exchanger or a radiator, the heat from the liquid can then be removed and dissipated. While liquid cooling is used less often for lighter engines due to the weight they add to the aircraft, many larger internal combustion engines rely on liquid cooling for their heat dissipation.

With robust and reliable engine cooling system parts, maintaining the integrity and functionality of internal combustion engines is made easier. At Complete Sourcing Solutions, we are your one-stop-shop for top quality aircraft parts and components that come from leading global manufacturers that we trust. When you are ready to take the first step of the procurement process, submit an Instant RFQ form through our website and a dedicated account manager will reach out to you in 15 minutes or less to provide a personalized quote based on your unique requirements.

1. harry walker
2. Posted on March 8, 2021
aviation

Related Blogs