Question

Which of these statements is true?

(a) The Gauss-Gradient method is a special case of the least-square gradient method

(b) The least-square gradient method is a special case of the Gauss-Gradient method

(c) The least-square method is not connected with the Gauss-Gradient method

(d) The least-square method is suitable only for the Cartesian grids

I have been asked this question in an online interview.

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

Answer 1

The correct answer is:

(a) The Gauss-Gradient method is a special case of the least-square gradient method

Explanation:

The Gauss-Gradient method and the least-square gradient method are both used for solving diffusion problems in computational fluid dynamics (CFD). In the context of discretizing the diffusion terms in numerical methods, the least-square gradient method is more general and can handle various grid structures. The Gauss-Gradient method, on the other hand, is a more specific form of the least-square gradient method that is applied to a particular type of grid, typically the structured grid in CFD. Therefore, the Gauss-Gradient method can be viewed as a special case or a specific implementation of the broader least-square gradient method.