旋转爆震波发动机推力性能研究
时间:2018-11-15 10:44 来源:毕业论文 作者:毕业论文 点击:次
| 摘要近年来，旋转爆震波发动机（RDE）成为研究热点，但是对推力和比冲的研究相对较少。本文采用实验和数值模拟两种研究手段，对影响 RDE 推力性能的四种因素：当量比、燃烧室长度、质量流率和喷管进行了详细分析并得出结论。实验采用环缝-喷孔对撞式 RDE，以 H2/Air 组合为推进剂，选定 RDE 出口背压为1atm。结果表明：在一定范围内，适当增加当量比有利于推力和比冲上升；燃烧室尺寸和工质质量流率对推力和比冲影响较大；在燃烧室末端加适当构型和适当尺寸的喷管可以有效提高发动机推力和比冲，在一定工况范围内Laval 喷管表现出优越性能。本文采用 7 组分 8步基元反应，忽略热传导、粘性和扩散输运特性,背压设为 1atm，对笛卡尔坐标系下的燃烧室进行三文数值模拟。分析了燃烧室长度和喷管对发动机推力和比冲的影响，结果表明：在相同工况下，推力和比冲随燃烧室长度增加而下降；在一定工况范围内收敛喷管表现出优越性能，Laval 喷管的扩张比和喉部尺寸对发动机的推力和比冲也有一定影响。30262 毕业论文关键词 旋转爆震波发动机 推力 比冲 喷管 数值模拟 Title The Study on Thrust Performance of Rotating DetonationEngineAbstractIn recent years, rotating detonation engines (RDE) become a hot topic, but thereare relatively few studies on the thrust and specific impulse. In this paper,experiments and numerical simulation were used to study four factors affectingthe performance of the RDE: the equivalence ratio, chamber length, mass flow rateand nozzle. After detailed analysis, the conclusions were drawn.The H2/Air rotating detonation engine with tilt slot-holes was used in thisexperiment. The atmospheric pressure was selected as back pressure. Results showthat: in a certain range of conditions, thrust and specific impulse increased withincreasing equivalent ratio; the length of combustion chamber and mass flow ratewas proved to influence thrust and specific impulse heavily. Moreover, the engineinstalled a nozzle at the outlet could generate greater thrust and specificimpulse. It had been proved that Laval nozzle performed best within a certain rangeof conditions.A reduced kinetic mechanism based on 8-step reaction and 7 species was usedto simulate three-dimensional rotating detonation engine. The transport processessuch as thermal conduction, viscosity and diffusion were omitted in the study.The back pressure was set to atmospheric pressure. Results show that, under thesame conditions, the longer the length of combustion chamber, the smaller thethrust and specific when mass flow rate is low. The converging nozzle exhibitedsuperior performance within certain range of conditions. The expansion ratio andthe width of the throat of Laval nozzle were also illustrated to have some influenceon the thrust and the specific impulse. Keywords Rotating detonation engine Thrust Specific impulse Nozzle Numerical simulation 目次 1引言1 1.1研究背景与意义.1 1.2旋转爆震波产生与传播机理.2 1.3旋转爆震波发动机研究进展与现状.3 1.3.1实验研究进展与现状3 1.3.2数值模拟研究进展与现状4 1.4论文主要研究内容.6 2H2/Air旋转爆震波发动机推力测量实验.7 2.1实验系统组成.7 2.2推力测量结果.8 2.2.1H2/Air当量比对旋转爆震波发动机推力性能的影响.9 2.2.2H2/Air质量流率对旋转爆震波发动机推力性能的影响.12 2.2.3轴向长度对旋转爆震波发动机推力性能的影响14 2.2.4喷管对旋转爆震波发动机推力性能的影响14 2.3本章小结.17 3H2/Air旋转爆震波发动机数值模拟.18 3.1控制方程组和计算方法.18 3.1.1控制方程组18 3.1.2求解方法19 3.2物理模型及边界条件.20 3.3三文数值模拟结果.21 3.3.1燃烧室长度对旋转爆震波发动机推力性能的影响21 (责任编辑：qin) |