Question

The total pressure and total temperature for a flow can only be talked about if the fluid particles are brought to rest by some means.

(a) False

(b) True

This question was addressed to me in an online quiz.

Enquiry is from Definition of Total Stagnation Conditions topic in section Compressible Flow – Preliminary Aspects of Aerodynamics

Answer 1

Correct choice is (a) False

Explanation: The stagnation quantities (total pressure, total temperature, total density etc) are defined quantities and exist in the flow at each point as if we are actually stopping the fluid particle. In reality, we don’t have to bring the fluid particles to rest to calculate them.