Question

In the absence of any source or sink, the steady-state diffusion problem is governed by _______________

(a) Fourier series

(b) Linear interpolation

(c) Taylor series

(d) Second order interpolation

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

My question is taken from Diffusion Problem topic in chapter Diffusion Problem of Computational Fluid Dynamics

Answer 1

Correct answer is (a) Fourier series

To explain: For a source-less steady state diffusion problem, the transfer of the flow variable (Φ) occurs only by diffusion. So, the transfer of Φ will be in the direction opposite to the increasing Φ. This is governed by Fourier series.