Question

Which of these statements is true?

(a) The Cartesian and non-Cartesian orthogonal grids lead to the same discretized equation

(b) A non-Cartesian orthogonal grid leads to an extra source term when compared to the Cartesian orthogonal grids

(c) The equations of the Cartesian and non-Cartesian orthogonal grids differ by a trigonometric function

(d) The equations obtained from a non-Cartesian grid has fewer terms when compared to that obtained from a Cartesian grid

The question was posed to me by my school principal while I was bunking the class.

I need to ask this question from Diffusion Problem topic in section Diffusion Problem of Computational Fluid Dynamics

Answer 1

The correct answer is:

(b) A non-Cartesian orthogonal grid leads to an extra source term when compared to the Cartesian orthogonal grids

When working with non-Cartesian orthogonal grids (such as polar or cylindrical coordinates), the equations typically introduce additional source terms due to the coordinate transformations. These terms account for the curvature or other geometric factors inherent in non-Cartesian grids.