Question

Which type of problem can be obtained by reformulating a problem with differential constraints by using the penalty method?

(a) A problem with no constraints

(b) A problem with variable constraints

(c) A problem with fixed constraints

(d) A problem with structural constraints

This question was addressed to me during an internship interview.

Asked question is from Penalty topic in chapter Flows of Viscous Incompressible Fluids of Finite Element Method

Answer 1

The correct choice is (a) A problem with no constraints

Best explanation: Penalty method is introduced in connection with constraint equations. It can also be used to reformulate a problem with differential constraints as one without constraints. In the viscous fluid flow problem, the constraints are created on velocity components by the elimination of pressure term, and thus, the Penalty method is applied.