Question

Find \(\frac{\partial u}{\partial r}\) at point 1 using forward difference method.

(a) 1000

(b) 100

(c) 500

(d) 5000

I had been asked this question during an internship interview.

I'd like to ask this question from Finite Difference Method in chapter Finite Difference Methods of Computational Fluid Dynamics

Answer 1

The correct option is (a) 1000

Explanation: Using the forward difference method,

\(\frac{\partial u}{\partial r}=\frac{u_2-u_1}{\Delta r}=\frac{5-0}{0.5×10^{-2}}=\frac{5}{5×10^{-3}}=1000.\)