Question

What is the difficulty in the direct use of nodal values without the deferred correction method?

(a) Convergence and stability

(b) Stability and accuracy

(c) Accuracy and Boundedness

(d) Boundedness and convergence

I have been asked this question in my homework.

My question is taken from Deferred Correction for High-Resolution Schemes topic in section High Resolution Schemes of Computational Fluid Dynamics

Answer 1

Correct choice is (a) Convergence and stability

For explanation: The difficulty arising when explicitly expressing a flow variable in terms of neighbouring values is the convergence rate. They violate one of the basic rules for stability and convergence which is the coefficients should be of the same sign.