The low-pressure turbine (LPT) is a crucial part of a twin-spool jet engine. It extracts energy from the exhaust stream, which helps turn the engine shaft and rotates the low-pressure compressor. A basic jet engine has several key components: an intake section, a compressor section, a combustion section, and an exhaust section. As exhaust air flows over the turbines, it creates the spinning motion needed to turn the engine shaft.
At the front of the shaft, compressor blades compress the incoming air to the desired pressure before it enters the combustion section. Here, the compressed air mixes with fuel and ignites, generating extremely hot exhaust gases. These gases exit the rear of the engine at a much higher pressure than the air that entered at the front, creating propulsion. This operation follows Sir Isaac Newton’s principle that states, “for every action, there is an equal and opposite reaction.”
The twin-spool design enhances the efficiency of the basic jet engine. In this setup, two sets of compressors and turbines rotate around a shaft within another shaft. The low-pressure compressor takes in air and initiates the first stage of compression. This air then moves into the high-pressure compressor for further compression. After being mixed with fuel and ignited, the hot gases flow over a high-pressure turbine, which extracts energy to spin the high-pressure compressor. Similarly, the exhaust air over the low-pressure turbine provides energy to spin the low-pressure compressor. This process continues until either fuel or air supply is cut off.
