Question

For which of these purposes, the DNS method is not suitable?

(a) Designing

(b) Simulation of the production of aerodynamic noise

(c) Effects of compressibility on turbulence

(d) To understand the mechanism of turbulence

I got this question by my school teacher while I was bunking the class.

This intriguing question comes from Direct Numerical Solution for Turbulent Models in section Turbulence Modelling of Computational Fluid Dynamics

Answer 1

Right choice is (a) Designing

The explanation is: DNS method cannot be used to make the aerodynamic design of a model. They are computationally very expensive. To employ a model in designing, the same simulation should be done many times to improve the design. As DNS models are expensive, they cannot be used repeatedly.