Question

How many terms of the Taylor series expansion is used in the Lax-Wendroff technique?

(a) (Δ t)^1 and (Δ t)^2

(b) (Δ t)^0,  (Δ t)^1 and (Δ t)^2

(c) (Δ t)^0 and (Δ t)^1

(d) (Δ t)^0

The question was asked during a job interview.

The question is from Finite Difference Methods in portion Finite Difference Methods of Computational Fluid Dynamics

Answer 1

The correct choice is (b) (Δ t)^0,  (Δ t)^1 and (Δ t)^2

The explanation is: The first three terms of the Taylor series expansion for the time marching term is used in the Lax-Wendroff Technique. This leads to the second-order accuracy of the system. Known values at previous time-step are used to find the value at the current time-step.