Question

Which of these does not result in two or more flows being dynamically similar?

(a) Streamlines are geometrically similar

(b) The shape of the blunt body is same

(c) Length of the body is same

(d) Non dimensional parameters remain same

This question was posed to me in an interview for job.

My doubt stems from Hypersonic Similarity topic in chapter Transonic and Hypersonic Flows of Aerodynamics

Answer 1

Right option is (c) Length of the body is same

The explanation is: Two or more flows are considered to be geometrically similar when the flow over the bodies remains identical. This happens when the shape of the bodies is identical and the variation in non – dimensional parameters remain same for the flows.