Research of flight trajectory of a catapult seat

Abstract

Activity contains the description of outcomes of numerical research of thee-dimensional spatial trajectories of a catapult (ejection) seat on a site of separation fiom a airplane. The researches are conducted in a broad band of parameters for various initial positions of an airplane and parameters of activity of a ejection seat. The special attention conversions on problems of emergency operation of ejection. In an outcome of researches the major factors influential in safe separation of a seat from an airplane are installed. ' Introduction One fiom the important and actual problem for safety of crew of airplanes is the problem of ejection of the pilot in emergencies. In actual practice frequently ejection is made from any spatial situations of an airplane defined by a particular emergency. The earlier conducted researches are executed for case of a plane problem and limited set of initial positions of an airplane. The purpose of the present activity is the research of three-dimensional spatial flight trajectories of a catapult seat in a broad band of the environmental conditions: a mode of flight and positions of an airplane. Main part Formulation. The basic equations. The developed algorithm and program of calculation describe a problem of calculation of spatial (three-dimensional) flight trajectory of a seat after separation from an airplane. For an initial segment of flight trajectory of a seat (after separation from an airplane) the closed set of equations of forces and moment which are operational on a seat is composed. The projections of forces to vertical, horizontal and lateral axes for plane, fast-track and ground coordinate systems are further obtained. Moving of a barycentre of a seat in fixed (ground) OXY coordinate systems are described by a system of differential equations which are looking like: Where: Cx, Cy, Cz factors of lift-to-drag ratio of a seat; T Force of a thrust of the jet accelerator(booster); G Weight of a seat; p angle between a direction of thrust vector N and axis OY; 0-7803-5729-9/99/$10.00