公开(公告)号：US4821510A

公开(公告)日：1989-04-18

申请号：US41264

申请日：1987-04-22

申请人： Warren L. Graser ,  Robert H. McCafferty

发明人： Warren L. Graser ,  Robert H. McCafferty

IPC分类号： F02K9/26 ,  F02K9/86 ,  F02K9/97

CPC分类号： F02K9/26 ,  F02K9/86 ,  F02K9/974

摘要： The invention is concerned with reducing the effect of a progressive surface area versus web thickness relationship in a rocket motor and is particularly useful with center perforate propellant grains where the chamber pressure versus time history is generally progressive. In a very short action time rocket motor, it is desirable to keep the chamber pressure as close as practical to the peak during the entire burn to increase the propellant burn rate. The multiple-stage throat makes this possible in a motor that uses the cost effective center perforate propellant grain design and operates by allowing a first stage throat to erode at a predictable rate while the area of the propellant burning surface is increasing. The motor initial Kn (propellant surface area divided by nozzle area) is raised by using a relatively small initial size for the first stage throat and as a result the rocket motor reaches peak chamber pressure quickly. With the erosion of the first stage matching the increasing propellant surface area the chamber pressure remains nearly constant. Near the end of the burn the first stage throat erodes out to the diameter of a non-eroding second stage throat which then becomes the controlling throat.

摘要翻译： 本发明涉及降低火箭发动机中渐进表面积对卷材厚度关系的影响，并且对于中心穿孔推进剂颗粒特别有用，其中腔室压力与时间历史通常是渐进的。 在非常短的动作时间火箭发动机中，期望在整个燃烧期间保持腔室压力尽可能接近峰值以增加推进剂燃烧速率。 多级喉管在使用成本有效的中心穿孔推进剂颗粒设计的电动机中使其成为可能，并且通过允许第一级喉道以可预测的速率侵蚀，而推进剂燃烧表面的面积增加。 电动机初始Kn（推进剂表面积除以喷嘴面积）通过对于第一级喉部使用相对较小的初始尺寸而升高，并且因此火箭发动机快速达到峰值室压力。 随着第一阶段的侵蚀与增加的推进剂表面积匹配，室压力保持几乎恒定。 在燃烧结束时，第一阶段的喉部腐蚀到不侵蚀的第二阶段喉部的直径，然后其变成控制喉。