高马赫数燃烧室离散孔燃料膜热防护和减阻特性  

Thermal protection and drag reduction characteristics of discrete hole film cooling in high Mach number combustor

作　　者：韦鼎元 章思龙 韦健飞 左婧滢 李欣 鲍文[1] WEI Dingyuan;ZHANG Silong;WEI Jianfei;ZUO Jingying;LI Xin;BAO Wen(School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]哈尔滨工业大学能源科学与工程学院,哈尔滨150001

出　　处：《航空学报》2024年第11期181-195,共15页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(52176037)。

摘　　要：为了探究碳氢燃料化学反应对离散孔气膜冷却特性和减阻特性的影响,选择4种离散气膜孔构型:圆柱型孔(CH)、交错叉排孔(MH)、交叉射流孔(DJH)、收缩扩张孔(CEH),开展高马赫数燃烧室内离散孔气膜数值研究,分析对比了碳氢燃料化学反应对不同离散孔气膜冷却特性和减阻特性的影响。研究结果表明,碳氢燃料化学反应使得近壁面区域冷却射流动量降低,冷却射流形成涡旋结构强度减弱。碳氢燃料化学反应通过裂解吸热反应提高了离散孔气膜冷却效率,扩展离散孔气膜冷却的展向覆盖范围。其中,交叉射流孔和收缩扩张孔射流展向速度分量大进而冷却覆盖范围较大。边界层内碳氢燃料燃烧减阻作用进一步降低壁面剪切应力,燃烧导致涡结构耗散减少以涡结构主导的掺混过程,掺混程度降低促使燃烧减阻性能减弱,交错叉排孔和收缩扩张孔分别有27.4%和18%的减阻效果。To investigate the influence of hydrocarbon fuel chemical reactions on the film cooling and drag reduction characteristics of discrete holes,we selected four types of discrete hole configurations:Cylindrical Hole(CH),Multiple Hole(MH),Double Jet Hole(DJH),and Contraction Expansion Hole(CEH).A numerical study of discrete hole film in a high Mach number combustor was conducted to compare the effects of hydrocarbon fuel chemical reactions on the film cooling and drag reduction characteristics of different discrete holes.The results indicate that chemical reactions of hydrocarbon fuels reduce the momentum of the cooling jet near the wall and weaken the intensity of the vortex structure formed by the cooling jet.However,these chemical reactions improve the film cooling efficiency of discrete holes through endothermic cracking reactions,leading to an expanded spanwise coverage of the film cooling.Specifically,the double jet hole and contraction expansion hole exhibit a large spanwise velocity component and extensive cooling coverage.Furthermore,the drag reduction effect of hydrocarbon fuel combustion in the boundary layer contrib-utes to a reduction in wall shear stress,while combustion itself leads to a decrease in vortex structure dissipation.However,the mixing process,which is dominated by vortex structures,is reduced due to a decrease in the degree of mixing,ultimately weakening the drag reduction performance of combustion.The drag reduction effects of the multiple hole and contraction expansion hole are calculated to be 27.4%and 18%,respectively.

关 键 词：超声速气膜冷却 碳氢燃料 离散气膜孔 减阻 边界层燃烧 

分 类 号：V235.2[航空宇航科学与技术—航空宇航推进理论与工程]