基于OpenFOAM的三维H2/Air连续旋转爆轰流场数值模拟

Three-Dimensional Numerical Simulation of H2/Air Continuous Rotating Detonation Flow Field Based on OpenFOAM

关键词:  旋转爆轰流场  反射激波  传播特性  数值模拟  压力增益

Key words:  Rotating detonation flow field  Reflected shock wave  Propagation characteristics  Numerical simulation  Pressure gain

摘要:

为进一步研究旋转爆轰流场特征，基于开源计算流体动力学软件OpenFOAM，采用9组分19步的基元化学反应模型，对H₂/Air连续旋转爆轰流场进行了三维数值模拟，得到了旋转爆轰波稳定传播时燃烧室内部流场的详细结构，研究了燃烧室头部激波的传播特性，分析了旋转爆轰燃烧室的压力增益性能。结果表明：旋转爆轰波后的第一道反射激波在由燃烧室外壁面向内壁面传播过程中反射激波的高度增加并在靠近内壁面附近与滑移线交汇形成局部高温高压区域；旋转爆轰波在外壁面位置处相位约落后于内壁面0.003rad~0.15rad，其相位差随燃烧室曲率差的增加而增大；燃烧室头部反射激波数目受到曲率差和进气总压的影响，燃烧室曲率差增大，反射激波数目减少，进气总压增大，反射激波数目增多；燃烧室压力增益保持在0.3以上，在进气总压一定的条件下，压力增益随着燃烧室曲率差的增大有增加的趋势。研究结果揭示了三维旋转爆轰流场的精细结构和燃烧室头部激波的传播规律。

Abstract:

To further study the flow field characteristic of rotating detonation, based on the open source computational fluid dynamics (CFD) software OpenFOAM, 19 species and 9-step reaction kinetics model was used to simulate the three-dimensional flow field of H₂/Air continuous rotating detonation. The detailed structure of the flow field in the combustor was obtained when the rotating detonation wave propagated steadily. The propagation characteristics of shock wave near the combustor head were studied. The pressure gain performance of rotating detonation combustor was analyzed. The results show that the first reflected shock wave after rotating detonation wave propagates from the outer wall of combustion chamber to the inner wall, and the height of reflected shock wave increases, and a local high temperature and pressure region is formed near the inner wall and intersects with the slip line. The phase of the rotating detonation wave on the outer wall is about 0.003rad to 0.15rad behind that on the inner wall, and the phase difference increases with the increase of the difference of combustion chamber curvature. The number of reflected shocks near the head of combustion chamber is affected by the stagnation pressure and the difference of curvature. The number of reflected shocks decreases with the increase of the difference of combustion chamber curvature, while the number of reflected shocks increases with the increase of stagnation pressure. The pressure gain of combustor keeps above 0.3. When the stagnation pressure is constant, the pressure gain increases with the increase of the curvature difference of the combustor. The results reveal the fine structure of the three-dimensional rotating detonation flow field and the propagation law of shock wave near the combustor head.