Question

What are the flux limiters for upwind and downwind schemes respectively?

(a) 0 and 2

(b) 0 and 1

(c) 0 and ∞

(d) 1 and ∞

This question was posed to me in an online quiz.

My question is based upon High Resolution Schemes topic in chapter High Resolution Schemes of Computational Fluid Dynamics

Answer 1

Right answer is (a) 0 and 2

To elaborate: The TVD schemes are developed starting from the upwind scheme. If flux limiters are used, the upwind scheme will change its nature. So, no flux limiter is required in this case and hence flux limiter for an upwind scheme is 0. For downwind scheme, the whole profile in the Sweby’s diagram should be in the line Ψ=2. So, the flux limiter here is 2.