凹腔火焰稳定器组件界面的适配性研究

Suitability Investigation about Components Interface of Flame Holder with Cavity

关键词:  凹腔  复合材料  双模量  适配性  应力球张量法

Key words:  Cavity  Composite  Bimodulus  Suitability  Balls tensor method

摘要:

为研究超燃发动机凹腔火焰稳定器组件中陶瓷导流块与稳定器壳体的连接可靠性，针对来流马赫数6.0，总温1660K，总压2.5MPa的来流，计算了整个燃烧室的内表面温度分布。以此为输入条件，以凹腔火焰稳定器子结构为研究对象，并通过热传导分析计算得到凹腔火焰稳定器的体温度。对凹腔火焰稳定器进行了应力-应变分析，计算中特别考虑了碳化硅复合材料与陶瓷导流块的拉伸与压缩弹性模量不等这一特性。在全粘接情况下，从分析结果可以看出，由于导流块热膨胀系数高于稳定器壳体热膨胀系数，导流块将承受较大的压应力。在两者的粘接区端部均有较高的剪切应力及拉伸或压缩正应力，二者适配性较差。为了改善粘接区端部的应力集中问题，给出了中部粘接的连接方式。计算结果显示，粘接区域端部的正应力和切应力分别减小了78%以上和60%以上，此连接方式可较好地改善初始连接方式造成的稳定器壳体与导流块间的连接适配性差的问题。

Abstract:

To study the connection reliability between ceramic diversion block and stabilizer shell，which were the components of flame holder with cavity of scramjet，for the incoming flow at Mach 6.0，total temperature 1660K and total pressure 2.5MPa，the inner surface temperature distribution of the entire combustion chamber was calculated. Taking this as input conditions，the substructure of flame holder with cavity was taken as the research object，whose body temperature was obtained by heat transfer analysis and calculation. Especially considering the characteristic that tension and compression elasticity modulus of silicon carbide composite and ceramic block diversion was not equal，the stress-strain analysis for flame holder with cavity was made. In the case of full-bonding，it can be seen that diversion block needs to ensure a greater compressive stress because thermal expansion coefficient of diversion block is higher than stabilizer shell from the analysis results. There are higher shear stress and tensile or compressive normal stress at both ends of the bonding area. The suitability of the two is poor. In order to improve the stress concentration problems at bonding zone ends，central bonding connection is adopted. The results show the normal and shear stress at the end of bonding area is reduced by more than 78% and 60%，respectively. This connection can better improve the problem of poor suitability between diversion block and stabilizer shell due to initial connection.