Question

When heat is added in a constant area duct without friction (i.e., in Rayleigh flow), which of the following statements is true?

• A. Total temperature and total pressure decrease for both supersonic and subsonic flows at inlet
• B. Total temperature increases and total pressure decreases for both supersonic and subsonic flows at inlet
• C. Total temperature and total pressure increases for supersonic flows at inlet
• D. Total temperature remains constant and total pressure decreases for subsonic flows at inlet

Hint:

Rayleigh flow involves thermal effects — always consider energy changes and pressure loss.

Answer 1

The Correct Option is B

In Rayleigh flow, heat addition increases total temperature and decreases total pressure regardless of whether the inlet flow is subsonic or supersonic.