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为探究多凹腔燃烧室的燃烧流动过程,采用非定常方法对液态煤油超声速燃烧特性进行了数值研究。计算结果发现,随着燃烧释热的进行,一道拟正激波被推到靠近隔离段入口处,最大压比达到3.77,燃烧达到稳态需要22ms;上游凹腔处煤油液滴运动轨迹表现出很强的非定常性,其运动方向与当地流动时刻的压力条件相匹配,上凹腔附近的液滴穿透深度明显大于下凹腔的,液滴个数也大于后者;出口总压恢复系数为47.09%,与实验值47.50%很接近,出口燃烧效率达到72.91%,体现了多凹腔燃烧室在保证燃烧性能较好时总压损失较低的优点;扩张型面上的凹腔质量交换律大于平直型面上的,表明型面扩张有利于增强凹腔内燃料与主流空气的质量交换;计算预测的燃烧室侧壁、上壁、下壁压力均与实验值吻合得较好。
In order to investigate the combustion flow in a multi-cavity combustion chamber, a non-stationary method was used to study the supersonic combustion characteristics of liquid kerosene. The results show that with the combustion heat release, a quasi-normal shock wave is pushed close to the inlet of the isolation section, the maximum pressure ratio reaches 3.77 and the combustion reaches steady state for 22ms. The trajectory of the kerosene droplet in the upstream cavity shows Strong unsteady, the direction of its movement and the local flow of time pressure conditions match the drop near the upper cavity depth was significantly greater than the lower cavity, the droplet number is also greater than the latter; outlet total pressure recovery The coefficient is 47.09% which is very close to the experimental value of 47.50% and the outlet combustion efficiency reaches 72.91%, which shows the advantages of multi-cavity combustion chamber with lower total pressure loss when the combustion performance is better. The cavity quality The exchange law is larger than that of the flat surface, indicating that the expansion of the profile is beneficial to enhance the mass exchange between the fuel in the cavity and the mainstream air. The calculated pressure on the sidewall, the upper wall and the lower wall of the combustion chamber are in good agreement with the experimental values .