Question

Which of these formulae is used to find the area of the sub-elements in CFD?

(a) Vector product of two sides

(b) Half of the vector product of two sides

(c) Half of the base times height

(d) Half of the vector product of all three sides

I had been asked this question by my school teacher while I was bunking the class.

This question is from The Geometry of FVM Elements topic in chapter Finite Volume Methods of Computational Fluid Dynamics

Answer 1

The correct choice is (b) Half of the vector product of two sides

The explanation is: Sub-elements are in triangular shape. Half of the base times height is the formula generally used to find the area of a triangle. But, CFD uses the vector-based formula to make it algorithmically easier, which is given by half of the vector product of two sides.