Aircraft Engine Cooling System
An aircraft engine or aero-engine is the powerplant of a vehicle that works by igniting fuel with air in a combustion chamber to produce immense amounts of energy for powering systems and achieving flight. During operation, excess heat from an overheated engine can set fire to lubricants and cause major damage, such as warping engine surfaces, creating cracks, vaporizing oil, etc. Although most excess heat generated is removed through the exhaust system, that is not enough to ensure safety. To prevent temperature fluctuations, at least 33% of heat needs to be removed by the cooling system. Hence, proper cooling arrangements are necessary for the reliability and longevity of engine parts. Air and liquid cooling systems are assemblies that are often present on aircraft for the means of managing temperatures. Though liquid-cooled engines were regularly used in the early days of aviation, air-cooled engines became dominant in aircraft because of their lower weight and efficient designs. Nevertheless, some aircraft still use a liquid cooling system to dissipate heat from their engine or rely on a combination of both. Therefore, it largely depends on the type of engine one is using. Furthermore, various additional solutions can be used for cooling, including devices such as cowl flaps and radiators. In this blog, we will briefly discuss the types and functions of aircraft engine cooling systems.
In an air cooling system, atmospheric air circulates directly over an engine's heat dissipation fins or hot areas to control temperature. The most common air-cooled engines are radial engines in which air flows equally over each cylinder for even temperature distribution. All four, six, or eight-cylinder inline aircraft engines are air-cooled, except Rotax, Viking, and Subaru engines. The air-cooling system offers low drag and has negligible weight compared to liquid cooling designs. In addition, several fins are provided around heads and barrels to increase the total cooling effect. However, in winter or at higher altitudes, it can over-cool the engine. In such cases, a winterization kit is recommended to keep temperatures under operating conditions by controlling incoming airflow. Apart from fins, baffles and plates are provided to guide intake air to engine ducts for constant air pressure above the engine and below the top cowling.
When cool air is applied to cylinders, it grows warm as it absorbs heat, that of which must be exhausted after heat exchange. Therefore, cowl flaps that control the opening and closing of the lower cowling are used. These flaps are pilot operated and remain open during high power/low-speed operations, allowing more air to pass through during climb and taxi maneuvers. However, they increase the parasite drag of aircraft. Therefore, such flaps should remain closed during normal cruising and descents.
There is a weight penalty with the liquid type of cooling system, but it is offset by its ability to effectively keep all cylinders at an even temperature and not shock them during high-speed descents through the use of liquid coolant. Coolant can also be thermostatically controlled, so it will provide increased safety and more reliable temperature control when flying down mountain slopes and steep declines. In addition, liquid cooling allows an engine to warm up quickly while keeping it at a constant operating temperature. Another benefit is that liquid cooling improves reliability, reduces fuel consumption, and enhances engine life.
Radiators are another form of the cooling method used in automobiles, but they can also be employed in piston-engine aircraft. In an IC engine, the primary cooling element is the engine coolant which takes up all the heat from the engine block and cylinder head. The radiator works as a heat exchanger where it takes the heat from the engine coolant so that the coolant can return to use.
Conclusion
For a smooth operation and improved aircraft engine reliability, you must have an effective cooling system. If you require a cooling system or other various aviation parts, Aerospace Store is your one-stop solution. Aerospace Store is owned and operated by ASAP Semiconductor, which has an inventory of over two billion new, used, obsolete, and hard-to-find parts for aerospace, civil aviation, and defense industries. We offer streamlined and effective purchasing solutions with a NO CHINA SOURCING pledge. Moreover, we provide our customers with rapid lead times and exceptional cost savings on all items. In addition, our customers can utilize our interactive website to search for any item through our database using our search engine and various filters. For more related information, call or email us at your convenience; we will be happy to serve you 24/7x365.
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