Combustion engines have been used on aircraft ever since the Wright brothers' first flight in 1903. Though their design has changed over the years, all combustion engines still work by burning a mixture of fuel and air to generate thrust. While the fuel is loaded on the plane already at the right consistency for use, the air which the engine collects needs to first be compressed. To use only as much fuel as necessary, airplane combustion engines rely on high powered compressors which condense the air they take in, making for an oxygen-rich fuel-air mixture that can be ignited with ease. Though there are many different compressors to choose from, most can be divided into two major categories: centrifugal and axial. In general, whereas centrifugal compressors have the air flowing outward perpendicular to the axis of rotation, axial compressors have the air flowing parallel to the axis of rotation. To learn more about compressors and how they work, read on as we discuss the major differences between these two major types.
How Do Axial Compressors Work?
Axial compressors are essentially made up of a combination of spinning and stable blades that force the air through tight spaces to compress it. In the mechanism, there are several rows of blades with a winglike shape. Some of these rows are called rotors, and they are connected to the central shaft and rotate at high speeds. Other rows called stators are fixed to the casing and do not rotate. As the air flows through each row, it is spun and forced through small openings between the blades so that oxygen atoms are pushed closer and closer together. Therefore, when the air finally reaches the combustion chamber, it will have been heated and condensed so that igniting the air-fuel mixture is quick and powerful.
How Do Centrifugal Compressors Work?
Centrifugal compressors work differently than axial compressors in that the air flows perpendicular to the axis of rotation. So, rather than using a mix of stable and rotating blades, centrifugal compressors only use a set of spinning blades that are shaped to propel the air outward in a spiral. Just like in an axial compressor, the air is forced through tight spaces between the blades, but this time with a different angle of motion.
Comparing the Two Types
Axial and centrifugal compressors work similarly in how they condense the oxygen in the air before it reaches the combustion chamber, but each type comes with its own advantages and disadvantages. In general, axial compressors are highly efficient and have large flow rates in relation to their size. They also offer the most compact and lightweight option for compressing large volumes of air and have the lowest cost per-flow rate for large flow rate applications. However, they are also more difficult to manufacture, have high starting power requirements, and are sensitive to flow disruptions, as well as aerodynamic stall and angle of attack. In contrast, centrifugal compressors are easy to design and produce, require low maintenance, have fewer rubbing parts, and are less sensitive to flow disruptions. Nevertheless, they do require a large front area for certain flow rates, are unsuitable for high compression, and are sensitive to changes in gas composition.
Overall, axial compressors are well suited for large volume, high flow rate applications, whereas centrifugal compressors may be a more effective choice for general operations. Regardless, both compressor types are frequently used on aircraft as a dependable source of air compression. Whether you are looking for high-quality compressor parts or other aircraft appliances, you can depend on ASAP Buying as a trusted distributor of engine components and other aircraft parts. Beyond giving our customers access to a vast inventory of reliable aviation components, our market expertise and purchasing power allows us to leverage time and cost savings for all the items we offer. If any of the products in our catalog pique your interest, you may send an Instant RFQ form to receive a quote for your comparisons in just 15 minutes or less!
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