Question

In a turbojet engine, thrust specific fuel consumption ________ with increasing compressor pressure ratio and __________ with increasing turbine inlet temperature (within range of operation).

• A. decreases, increases
• B. decreases, decreases
• C. increases, increases
• D. increases, decreases

Hint:

Optimal design of compressor and turbine stages is crucial for achieving low fuel consumption in jet engines.

Answer 1

The Correct Option is B

Step 1: Analyze the Effects on TSFC.
Increasing the compressor pressure ratio generally improves the efficiency of the cycle, thereby decreasing the thrust specific fuel consumption (TSFC). Similarly, increasing the turbine inlet temperature (up to a certain limit) also tends to increase the efficiency of the engine, further decreasing TSFC.