A Wind Tunnel and Computer Investigation of the Low Speed Aerodynamic Characteristics of the Prone Escape System (PRESS)
Abstract
Due to new design technology, future jet fighters will fly at higher g levels than before. A previous preliminary design study was conducted to develop an ejection seat providing higher g-tolerance for the crewmember during maneuvering as well as improved windblast protection during ejection. This seat used the crewmember in a prone, or leaning forward, position. The Prone Ejection System was computer simulated at supersonic conditions in the earlier report and found satisfactory. It was the purpose of this present research to perform an experimental low speed study of the aerodynamic characteristics of the PRESS. Wind tunnel testing was performed to determine the static stability of the PRESS and measure pressures over the seat. It was determined that static pitch stability did not occur at the desired angle of attack, but could be easily corrected with aerodynamic fins and/or a shift in the center of gravity. Directional stability was also confirmed. An analytical experiment was also performed to determine whether a potential paneling code could be modified to predict flow conditions about the PRESS. An apparent body was constructed by including the regions of flow separation as part of the seat itself. Water tunnel flow visualization was used to determine the shape of the apparent body. The computer analysis showed that a paneling code could accurately predict the pressure coefficients on the cowling. Keywords: Subsonic wind tunnels; Computerized simulation; Aerodynamic stability. Theses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1988
- Accession Number
- ADA202768
Entities
People
- Lonnie R. Dillon
Organizations
- Air Force Institute of Technology