Design and Finite-Element Analysis of a Sabot for a 60mm Flared Ramjet.

摘要

A basic solid-fuel ramjet (SFRJ) projectile is shown in figure 1. A ramjet motor consisting of an inlet, hydrocarbon fuel and composite nozzle is housed in a hollow steel case. In flight, air is forced through the inlet, burns with the fuel, accelerates out of the nozzle, and thus produces thrust. The Chemical Systems Division of United Technologies Corporation (UTC), through tests done in conjunction with the Ballistic Research Laboratory (BRL), discovered that the rate at which the fuel regressed, i.e. the burn rate, was affected by the spin rate of the SFRG. Higher spin causes a slower regression rate and hence less thrust. In order to quantify this effect, UTC and BRL developed a computer program to flight-test a flare-stabilized SFRJ at four different spin rates. Four 105mm computer M68 gun tubes are to be utilized: the standard twist (one revolution in eighteen calibers, one-in-18), and three specially made tubes: a smooth bore, a one-in-12 and a one-in 25 twist. This report details the design and finite-element analysis of a sabot package for the 60mm flared ramjet to be utilized in the spin test program. Also included are the results from the initial structural integrity flight-test, and the necessary design modifications.