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针对战术发动机的飞行条件,建立了固体发动机过载条件下内流场两相流计算模型,开展了3种典型中、小飞行过载下的流场计算,详细分析了燃烧室内凝相颗粒冲刷参数分布,并初步分析了颗粒聚集状态与绝热层烧蚀之间的关系。研究结果表明:(1)当横向过载达到一定程度,在发动机筒段绝热层表面,在承载面沿着流场方向会形成一条粒子浓度缓慢增大的聚集带,而在非承载面粒子分布较为稀疏。(2)过载大小对颗粒冲刷速度的影响不明显,主要原因是燃气本身对颗粒运动的轴向加速很大,而过载的作用体现不明显。(3)燃烧室中粒子密集区一定程度反映了该部位的烧蚀环境较为严酷,绝热层烧蚀主要由于凝相粒子低速聚集导致了局部热增量加剧并引起了颗粒的二次聚集效应。因此,长时间中、小过载下,为了缓解燃烧室绝热层局部的严酷烧蚀环境,在已知粒子冲刷参数分布下,可增加局部绝热层设计厚度,调整发动机的飞行姿态使承载面呈现正负交替的过载以及增加发动机自身旋转动作。
According to the flight conditions of the tactical engine, two-phase flow model of the internal flow field under the condition of solid engine overloading is established. The flow field calculation under three kinds of typical middle and small flight overloading conditions is carried out. The distribution parameters of coagulation particles in the combustion chamber are analyzed in detail , And preliminary analysis of the relationship between particle aggregation and ablation of the insulation layer. The results show that: (1) when the transverse load reaches a certain level, an agglomeration belt whose particle concentration slowly increases along the flow field direction is formed on the surface of the insulation layer of the engine barrel section, while the particle distribution on the non-bearing surface is relatively Sparse. (2) The influence of overload on the velocity of particle erosion is not obvious, mainly due to the fact that the gas itself accelerates the axial acceleration of particle motion and the effect of overload is not obvious. (3) The dense area of the particle in the combustion chamber reflects the harsh ablation environment of the site to a certain extent. The ablation of the heat insulation layer is mainly caused by the local heat increment exacerbated by the low-speed aggregation of the condensed particles and the secondary agglomeration effect of the particles. Therefore, for a long time and under small overload, in order to alleviate the harsh local ablation environment of the combustion chamber insulation layer, the design thickness of the local insulation layer can be increased under the known particle erosion parameter distribution, and the flying attitude of the engine is adjusted to make the bearing surface appear positive Negative alternating overload and increase the engine’s own rotation.