Computational Analysis of High-Speed Ejection Seats

Abstract : This final report documents the results of a study demonstrating the use of analytical computational fluid dynamics methods to predict the aerodynamic characteristics and flowfield details of a typical ejection seat with an occupant. This feasibility study was limited to two dimensional flow around a configuration defined by a longitudinal plane of symmetry through the center of the ejection seat. Navier-Stokes codes were used to predict the steady and time-dependent transonic and supersonic flow characteristics for a series of ejection seats for which wind tunnel data are available, and comparisons of measured and predicted forces and moments are presented to show the trends produced by the analysis techniques. Structured and unstructured grids were considered in the calculations to demonstrate the capability of the method and to guide the planning for a future three-dimensional approach. The report concludes with recommendations for a program leading to the development of a three-dimensional CFD analysis code applicable to the study of windblast loads and minimum drag design of modern ejection seats. (AN)