Date of Award

Spring 2012

Document Type


Degree Name

Doctor of Philosophy (PhD)


Mechanical Engineering

Committee Director

Gregory V. Selby

Committee Member

Sushil K. Chaturvedi

Committee Member

Arthur C. Taylor, III

Committee Member

Alok Verma


A computational parametric investigation was conducted to study the effect of variations to several geometric parameters on the performance of a two-dimensional model scramjet engine (square cross section area for 3-D model). Geometric parameters included backstep location, height, and angle and fuel injector angle, diameter, and location. Two- and three-dimensional geometries have been studied, using a finite-volume computational fluid dynamics (CFD) code (FLUENT) with structured grids with sizes between 50,000 and 90,000 cells for the two-dimensional geometry and with structured hexahedral grid sizes between 650,000 and 949,725 cells for the three-dimensional geometry. Otherwise, identical values of program inputs were utilized for the two- and three-dimensional simulations.

Performance parameters investigated were combustion efficiency, thrust, pressure losses, and the equivalence ratio for the hydrogen-air combustor. A set of values for independent variables was identified which resulted in maximum thrust, minimum pressure losses, and an equivalence ratio close to unity.