According to the centrifugal flow compressor description, what happens to pressure as speed increases?

• A. Reduces pressure as speed increases
• B. Increases pressure
• C. Stays the same
• D. Fluctuates unpredictably

Answer: (A)

The essential idea is that increasing the impeller speed in a centrifugal flow compressor adds more energy to the air, and that energy is converted into higher pressure downstream. As speed goes up, more work is done on each unit of gas, boosting the outlet stagnation pressure, and the diffuser then converts more of that kinetic energy into static pressure, raising the overall pressure rise for a given flow. So, under normal steady operation, pressure increases as speed increases. The other options don’t fit this behavior: it wouldn’t intentionally reduce pressure with higher speed, it wouldn’t stay the same, and it wouldn’t rise and fall unpredictably in a well-designed, stable compressor—fluctuations would indicate transient or unstable conditions rather than the typical trend.