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本文分析了喷管型面结构对固体推进剂火箭发动机性能和效率的影响。本研究使用三种分析方法,它们是:赫克力斯的Ⅰ_(SP)法(HIMET),固体性能程序(SPP)和普度大学 Jo-seph Hoffman 博士的直接寻求法。这些分析方法确定发动机中的流动和热损失,并以比冲(I_(SP))损失表示。在本分析中,分别考虑了扩散、摩擦、热、粒子滞后、侵蚀和化学不平衡等方面带来的损失。对采用抛物线、园弧线和特征线的喷管型面的发动机进行了性能比较。在固定喷管外轮廓(长和直径)不变的条件下研究了典型的低空和高空工作的发动机。这些计算结果对喷管型面设计有了有益的深入理解。本研究指出:第一,最佳起始扩散角随所采用的喷管型面和分析方法而变;第二,对于给定的喷管外轮廓,不论是抛物线型面、园弧线型面还是特征线型面,所获得的最大比冲基本上是相同的;第三,如果喷管型面不是最佳,就会出现明显的性能损失;第四,分析的Ⅰ(SP)预示方法能有效地用于固体推进剂火箭发动机的喷管型面设计;第五,可延伸出口锥能改进主喷管的性能。
This paper analyzes the effect of nozzle profile structure on the performance and efficiency of solid propellant rocket motors. Three methods of analysis were used in this study: the direct seeking method of Hercules’ I_ (SP) method (HIMET), the Solid Performance Procedure (SPP), and Dr. Jo-seph Hoffman of Purdue University. These analytical methods determine the flow and heat losses in the engine and are expressed as specific impulse (I SP) losses. In this analysis, the losses caused by diffusion, friction, heat, particle lag, erosion and chemical imbalance are separately considered. A performance comparison of engines with nozzle profiles with parabolic, circular arcs and characteristic lines was performed. A typical low-altitude and high-altitude engine was studied under the condition that the outer contour (length and diameter) of the fixed nozzle was unchanged. The results of these calculations provide a helpful insight into nozzle profile design. This study shows that: First, the optimum initial divergence angle varies with the nozzle profile and analytical method used. Second, for a given nozzle profile, whether parabolic or circular arc profile Characteristic line profile, the maximum specific impulse obtained is essentially the same; third, significant loss of performance occurs if the nozzle profile is not optimal; and fourthly, the analytical I (SP) prediction method is effective Fifthly, extendable exit cone can improve the performance of the main nozzle.