FAA Powerplant Written Practice Test

What is the function of the fuel oil heat exchanger in a turbojet engine?

1. Decreases fuel pressure

2. Increases fuel temperature

3. Filters the fuel before combustion

4. Extracts moisture from the fuel

The correct answer is: Increases fuel temperature

The function of the fuel oil heat exchanger in a turbojet engine is to increase the fuel temperature. This component plays a crucial role in ensuring that the fuel is heated to an optimal temperature before it enters the combustion chamber. Proper fuel temperature is essential for efficient atomization and combustion within the engine. By raising the fuel temperature, the heat exchanger helps prevent potential issues with fuel viscosity, especially in cold weather conditions, allowing for better flow and performance. It also assists in reducing the chances of fuel icing and ensures that the fuel can atomize properly when injected into the combustion chamber, leading to more effective combustion and overall engine efficiency. Understanding this function highlights the importance of thermal management in turbojet engines and reveals how various systems work synergistically to optimize performance.