Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Mechanical Engineering

First Advisor

Jeffrey Doom


CFD, DES, LES, OpenFOAM, passive scalar, StarCCM


The scramjet engine equipped with a modern-day airliner would allow for very quick travel across the United States. The major problem is that designing such an engine and testing it to make sure it is safe would cost millions if not billions of dollars. Computational fluid dynamics allows for complex designs to be tested but can still take many days, weeks, or even months to complete. With the use of computational fluid dynamics (CFD), the scramjet engine can be analyzed to determine a quicker way to test and develop a reliable configuration in addition to analyzing the effects of different fuels on performance and efficiency. The current problem, when using CFD to analyze the scramjet engine, is that it cannot solve the simulation in a timely manner, which is very important in industry. While there are solvers for CFD that have chemistry for combustion, they are extraordinarily complex and again take a large amount of time to converge on a solution. Even solvers that only include a small number of species, such as five to ten, require numerous days or even weeks to converge on a solution when using HPC. Using the passive scalar function within CFD programs, various fuels can be analyzed for mixing, combustion, and performance. The passive scalar mimics injecting dyed air into the geometry; the converged solution displays how the air (fuel) would distribute throughout the geometry as time passes on. In recent years, much research has been done on the scramjet engine, but much more research and testing are needed before the scramjet engine can become widely accepted for use. Currently, scramjet engines are only utilized for military applications including aircrafts and missiles. This thesis was conducted to research the effects of using passive scalar mixing to simplify the simulation process of combustion within a scramjet engine cavity. The simulations were performed using Reynolds Average Navier Stokes, Detached Eddy Simulations, and Large Eddy Simulation solvers in StarCCM. In addition, OpenFOAM utilized the sonicFOAM solver to perform simulations. The simulations were based on the Air Force Research Lab, AFRL, scramjet testing model. To assess the accuracy of the simulation results, it is crucial to validate the simulations against experimental data. Therefore, the simulation results were compared with David Peterson’s simulation results ([5],[6],[7]) and agreed.

Number of Pages



South Dakota State University



Rights Statement

In Copyright