What Is the Main Source of Cooling an Aircraft Engine?

Aircraft engines experience the brunt of excessive heat, sourcing from a number of other components in the engine assembly. High engine temperatures can lead to a loss of power, excessive oil consumption, detonation, and eventually, engine failure. The heat generated by aircraft engines and their related components should be directed away through some type of cooling mechanism, ensuring the aircraft’s reliability and extended service life. In this blog, we will be covering some of the most common cooling systems implemented in aircraft, their features, and how they work.

Cooling systems are designed to reduce and control the temperatures of the cylinder barrels and heads within the engine that contain the combustion chamber and valves. Bearings and pistons, on the other hand, utilize an engine oil cooler to cool down its various components. While most aircraft are air-cooled, a number of aircraft use a liquid cooling mechanism as well.

Radial engines are one type of engine that uses an air cooling mechanism. This process consists of all cylinders being equally exposed to airflow and provided even temperature distribution. Air-cooled cylinders have a number of cooling fans positioned around the heads and barrels, increasing the total cooling area. During the winter time, excessive cooling is possible; thus, a winterization kit can be used to control the incoming airflow. Air is guided from the intakes to the engine ducts by baffles and plates, allowing the aircraft to maintain a positive air pressure between the engine and cowling.

Cowlings serve a particularly important role, as they provide a means for exhausting the resulting warm air sourced from the engine and engine cylinders. This is sometimes controlled by the cowl flap assembly. These flaps remain open during high power/low speed operations. While they increase parasite drag when in an open position, they should remain closed during normal cruise and descent. Cowling flaps are opened and closed by electric motor-driven jackscrews, hydraulic motors, or in some cases, manually.

Liquid cooling is another type of cooling system in which all cylinders are temperature-controlled with fluids. Around each cylinder is a series of water jackets wherein liquid coolant is dispersed, taking away from the excess heat. This excess heat is then dissipated by a heat exchanger or radiator via airflow. Turbine engines, in particular, use secondary airflow to cool both internal and external components.

It is important to keep in mind that cylinders cannot be shock cooled during high speed/low power descents, and the coolant is thermostatically controlled. As a result, the engine has a quicker warm-up time and maintains a constant operating temperature. This translates to extended reliability, increased fuel efficiency, and a longer service life. In a liquid cooling system, it is important to routinely check the fluid lines and radiators to ensure optimal functionality.

In some aircraft, you may find a third cooling mechanism provided by augmentors. Augmentor tubes within each nacelle facilitate additional airflow. As exhaust gas is fed into the augmentor tubes, the exhaust gas mixes with air that has made its way over the engine and heats it to create a high-temperature, low-pressure, jet-like exhaust. The resulting low-pressure area in the augmentors produce additional cooling air over the engine. Augmentors utilize the exhaust gas velocity to generate cooling airflow that does not require prop wash.

Due to cooling systems being incredibly important, it is critical to ensure their optimal functionality. Routine maintenance checks of internal components and external structures guarantees that your aircraft is ready for standard flight operations, all of which are crucial for keeping both aircrew and passengers safe. As there are a myriad of parts and components that make up an aircraft, they often necessitate repair or replacement. When you find yourself in need of a leading online distributor you can trust, rely on ASAP Supply Chain for all your operational needs.

At ASAP Supply Chain, we are committed to providing customers with superior quality aircraft parts, all of which have been subjected to a number of rigorous quality assurance measures, tests, verifications, and assessments. More than that, we operate with AS9120B, ISO 9001:2015, FAA AC 00-56B, ESD S20.20-2014, and AS 6081:2012 certification and accreditation, ensuring the reliability and authenticity of all our items. For customers that are facing a time constraint or AOG situation, we offer expedited shipping services on a majority of our inventory.

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