Date of Award


Publication Type

Master Thesis

Degree Name



Mechanical, Automotive, and Materials Engineering

First Advisor

Barron, Ron

Second Advisor

Balachandar, Rambala


Computational fluid dynamics (CFD), Convergence criteria, Internal gear pumps, Internal relief valve, Meshing, Relaxation factors




Relief valves are widely used in the process industry. Their ultimate role is to mitigate adverse conditions that would jeopardize safety and incur catastrophic losses, especially with respect to human life. The primary focus of this research is to investigate the performance of relief valves, with the specific objective of reducing the cracking to full by-pass pressure in internal relief valves of positive displacement pumps. Two and three-dimensional computational fluid dynamics (CFD) models of an external relief valve are developed and used to evaluate the effects of the mesh, numerical parameters and boundary conditions on the results, including flow pressure and velocity field. Knowledge gained from the external relief valve study has guided the internal relief valve simulations, particularly with regards to sensitivity of the results to the mesh and other numerical settings. Numerical simulations were performed utilizing the CFD codes: ANSYS Fluent and STAR-CCM+.