UNSTEADY PRESSURE MEASUREMENTS IN A SUPERSONIC INLET DURING UNSTART SIMULATIONS

Unsteady pressure behavior during inlet unstart is a critical factor in understanding the performance and stability of supersonic systems. This thesis will investigate the unsteady pressure measurements within a supersonic inlet during unstart. By using a model developed by Ben Nikaido, Kulites were installed to record output voltages that were converted into pressure measurements. The experiment was conducted within a supersonic wind tunnel, where a louver system activated by a traverse mechanism induced back pressure, allowing a shock train to be formed and eventually pushed forward, leading to the inlet model unstarting. An upgraded data acquisition system was built so that the experiment could record unsteady pressure measurements and a shadowgraph while actuating the louver system. Once repeatability was proven, computational fluid dynamics (CFD) simulations based on the experiment were developed in ANSYS CFX, and computational solutions were developed. The experimental measurements and the CFD solutions showed that increasing back pressure caused the shock train to move upstream toward the inlet lip. The CFD solution was able to replicate the experimental data within reason, providing a window for further studies to be conducted.

Department dc:contributor.department

Mechanical and Aerospace Engineering (MAE)

Grantor dc:publisher

Monterey, CA; Naval Postgraduate School

Year dc:date.issued

2026

Author dc:creator

• Leaver, Nicodemus

Advisors dc:contributor.advisor

• Hobson, Garth V.
• Smith, Walter C.

Statement dc:rights

• This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.

Handle dc:identifier.uri

https://hdl.handle.net/10945/75011

OAI identifier oai:identifier

oai:calhoun.nps.edu:10945/75011