What Are Aircraft Engine Baffle Seals?

During standard engine operation, heat can quickly increase due to moving parts, combustion of fuel, and other mechanical processes. This heat can build up to dangerous levels if unchecked, damaging components and systems alike. One major way in which engines are typically cooled on an aircraft is through the use of colder air within the atmosphere that is directed throughout components and systems. Aircraft engine baffle seal material is an important element to engine cooling for piston powered aircraft, allowing for airflow regulation through an engine compartment. In this blog, we will discuss what engine baffles are, as well as how they cool aircraft engines.

When aviation was in its infancy, aircraft engine cooling was much more simplistic. Engineers designed engines with their finned cylinders within the slipstream so that they would be cooled down by ram air, which is referred to as velocity cooling. While this solution worked well for early engines, it proved inefficient for the more advanced and powerful engines that followed. With engines that were horizontally opposed or had multi-row radials, velocity cooling provided uneven results and would often cause an increase in drag that was detrimental to aircraft performance. As a solution, aircraft designers began to implement pressure cooling, which requires baffles and cowling for optimally reducing engine temperature.

Unlike the uncovered radial engines of early aviation, modern piston aircraft feature engines that are tightly cowled as to prevent weathering and wear caused by the extreme conditions that aircraft operate in. Within the cowling, aircraft engine baffle seal material and aluminum baffles are installed to create a division in the compartment, forming two chambers. The gap at the top of the engine is sealed to create pressure, and the upper chamber has high pressure while the bottom chamber has lower pressure. While the pressure difference between each chamber may be low, it still provides for an airflow that effectively cools the engine. During operation of the engine, hot air moves upwards into the upper chamber while cool air is directed below. Hot air may escape from the baffle seal and cowling system through openings in the cowl, and cooling air is directed into the chambers to continue the cycle.

Aircraft engine baffle seal material can operate efficiently for years at a time, providing for hundreds of hours of operation. As they reach the end of their service life, they may begin to lose flexibility which could affect the sealing properties. As the seal loosens, cooling air may escape and the engine will not be able to cool down properly. When this begins to occur, replacing baffles is important. When installing aircraft engine baffle seals, having the correct seals and fasteners is critical to avoid corrosion and ensure optimal securing of assemblies. Often, fasteners such as pop rivets are useful for air baffle installation.

After removing old and worn baffle seals with the correct tools, new baffle material may be installed. Templates can be created with sheet metal, cut and drilled to have the correct shape and ability for mounting. Bending baffles with a large bend radius is also important to not affect the integrity of the material. Installation is done carefully to ensure optimal incoming airflow and to prevent turbulence within the system. Installing the air baffle seals comes next, placing them with small overlaps to improve airflow. Once this is done, the seals can be riveted and sealed to ensure that they are all secure. To finish the installation process, the baffles are then anodized with a finish to protect them from corrosion.

Most often, aircraft engine baffle seal material is manufactured from silicone, due to its friction mitigating properties. Lower friction between the cowling and seals is important to reduce the chance of fatigue, cracking, and fretting of the fasteners. Silicone may also provide for less vibration from the airframe. The aircraft engine baffles themselves are most commonly made from aluminum, similar to many other structures and assemblies of an aircraft. Due to the critical operation of baffle seals to prevent overheating of the engine, it is highly recommended to procure high quality components to ensure efficient air flow and cooling.

When it comes time to begin sourcing the aircraft engine baffle seal material that you need for your next project or operation, Fulfillment 3Sixty has you covered with everything you are searching for. Fulfillment 3Sixty is owned and operated by ASAP Semiconductor, and we can help you find the engine and air baffle components that you need, new or obsolete. As a premier supplier of parts for the aerospace, civil aviation, and defense industries, we're always available and ready to help you find all the parts and equipment you need, 24/7x365. ASAP Semiconductor is an FAA AC 00-56B accredited and ISO 9001:2015 certified enterprise. For a quick and competitive quote, email us at sales@fulfillment3sixty.com or call us at +1-714-705-4780.