ABSTRACT

The solid fuel ramjet is one of the simplest air-breathing engines, characterized by increased specific impulse. This study focuses on a parametric investigation of the internal ballistics of a boron-containing solid fuel ramjet. A 2-D axisymmetric model of a ramjet combustor flying at Mach 2.5 was developed and solved numerically utilizing a commercial computational fluid dynamics code modified to address the specific issues of the problem. The simulation results were compared to the theoretical performance calculated by the chemical equilibrium code. The solid fuel regression rate was found to depend on the port diameter and thus decreases with time. Thrust regulation of ramjet engine was demonstrated using bypass air. The specific impulse was found to decrease with boron content, probably because of low combustion efficiency caused by either insufficient oxygen supply or short residence time of the boron particles.

摘要

固体燃料冲压发动机是最简单的吸气式发动机之一，其特点是比冲增加。这项研究的重点是对含硼固体燃料冲压发动机的内部弹道学进行参数研究。开发了以 2.5 马赫飞行的冲压发动机燃烧室的二维轴对称模型，并利用修改后的商业计算流体动力学代码解决了该问题的具体问题。将模拟结果与化学平衡代码计算的理论性能进行比较。发现固体燃料回归率取决于端口直径，因此随时间降低。冲压发动机的推力调节使用旁通空气进行了演示。发现比冲随着硼含量的增加而降低，