Theses and Dissertations

Issuing Body

Mississippi State University


Janus, J. Mark

Committee Member

Belk, Davy

Committee Member

Thompson, David. S.

Date of Degree


Document Type

Graduate Thesis - Open Access


Aerospace Engineering

Degree Name

Master of Science


James Worth Bagley College of Engineering


Department of Aerospace Engineering


Flow separation is a common fluid dynamics phenomenon that occurs within supersonic nozzles while operating at off-design pressures. Typically, off-design pressures result in a shock formation that leads to a non-uniformity of the exiting flow and creates flow separation and flow recirculation. So far, no effective solution has been presented to eliminate flow separation and increase the total performance of the nozzle. The purpose of this work is to investigate whether a Gurney flap may beneficially affect the exiting flow pattern. For a better understanding of the Gurney flap effect, this investigation used a supersonic nozzle geometry based on a previous study by Lechevalier [33]. Results from the tested cases showed a poor effect of the flap at high free-stream Mach number and lower pressure ratio. Simulations of different flap heights along with different parameters showed a slight increase of thrust.



Supersonic nozzle||Computational fluid dynamics||flow separation||Gurney Flap