Question

The difference scheme to be used in the hybrid system is chosen by evaluating the ____________

(a) Local Peclet number

(b) Global Peclet number

(c) Reynolds number

(d) Nusselt number

The question was asked in a national level competition.

This intriguing question comes from Convection-Diffusion Problems in section Convection-Diffusion Problems of Computational Fluid Dynamics

Answer 1

The correct choice is (a) Local Peclet number

The explanation: The central differencing scheme works well with low Peclet numbers and the upwind scheme works well for high Peclet numbers. So, the differencing scheme to be used in this method is chosen using the Peclet number.