Question

Which of the following is most difficult to analyze?

(a) solid

(b) plasma

(c) fluids

(d) cannot be determined

The question was posed to me in unit test.

My enquiry is from Finite Control Volume Approach topic in chapter Aerodynamics – Fundamental Principles and Equations of Aerodynamics

Answer 1

The correct choice is (c) fluids

The explanation is: Because fluid (liquid and gas) is a “squishy” substance. While the solid body is geometrically well defined and hence its motion can be defined easily. Whereas, in fluids, it is difficult to decide the qualitatively model the motion of the fluid.