Question

The high-resolution schemes formulated using the NWF method with the equation \(\tilde{\phi_f} = l\tilde{\phi_c}+k\) are stable without any alteration when __________

(a) k>2

(b) l>2

(c) k>l

(d) l>k

This question was posed to me at a job interview.

I would like to ask this question from High Resolution Schemes in section High Resolution Schemes of Computational Fluid Dynamics

Answer 1

Correct choice is (d) l>k

To elaborate: The NWF formulation of the high-resolution schemes, when the value of l is greater than the value of k, the diagonal coefficients are all positive and hence the solution is highly stable. This is the case everywhere except a narrow region in NVD.