动态舱门对空腔复杂流动和噪声特性影响分析  

Investigations of complex cavity flows and noise induced by moving cavity doors

作　　者：李晓东 姜蔚婉 屈崑[1] 蔡晋生[1] LI Xiaodong;JIANG Weiwan;QU Kun;CAI Jinsheng(School of Aeronautic,Northwestern Polytechnical University,Xi’an 710072,China;Chengdu Aircraft Design&Research Institute,Aviation Industry Corporation of China,Chengdu 610091,China)

机构地区：[1]西北工业大学航空学院,西安710072 [2]中国航空工业集团成都飞机设计研究所,成都610091

出　　处：《空气动力学学报》2022年第3期175-189,I0004,共16页Acta Aerodynamica Sinica

摘　　要：为研究运动舱门对内埋弹舱(空腔)非定常流场和舱内噪声特性的影响,开发了应用于运动问题的动态嵌套重叠网格组装方法,采用改进的脱体涡模拟方法对亚声速流场(Ma=0.6)进行了高精度数值模拟。首先采用空腔标准模型(M219)验证所用的高精度数值格式的有效性,然后应用发展的方法对干净空腔(C201)、带静态舱门(30°、60°、90°和120°)的空腔以及运动舱门的空腔进行模拟,并分析静、动态舱门对空腔湍流流场和腔内气动噪声的影响。针对运动舱门的非稳态非定常流动问题,采用经验模态分解方法分析空腔中的湍流脉动特征和声压级。通过分析研究结果发现,与干净空腔相比,舱门小开度(30°)时,舱门会限制法向和展向的流动,从而降低腔内流场与外部流场的流动掺混和交换,腔内壁面总声压级比干净空腔低5~8 dB,但是两者变化趋势一致,且二阶Rossiter模态频率偏高;在打开角度较大(60°以后)时,舱门对腔内流动的影响主要表现在展向,此时空腔上方的剪切层涡结构运动的高度更高,舱门阻碍噪声的展向传播,使得腔内的总声压级升高(3~10 dB不等),二阶Rossiter模态的强度增大。然而舱门开启过程中,腔内总声压级介于小开度与大开度之间,与干净空腔水平相当;在舱门打开角度为90°时,腔内总声压级呈现与准定常模拟结果类似的分布,该研究对真实弹舱的流动分析与设计有指导价值。Turbulent flows in cavities play an important role in the generation of cavity noise and are inevitably modulated by moving doors.This paper proposes a dynamic hierarchical overset method and integrates it into Improved Delayed Detached-Eddy Simulations to characterize the impact of non-stationary doors on cavity flows.The numerical methods,validated using a canonical cavity(M219),are applied to simulate subsonic(Ma = 0.6) flow fileds in cavities(C201) without doors,with stationary doors(with opening angles of30°,60°,90°,and 120°),and with moving doors.Turbulence statistics and cavity noise in a statistically unsteady flow induced by moving doors are analyzed using the Empirical Mode Decomposition.For stationary doors with an opening angle of 30°,cavity flow is constrained in the cross-flow directions,suppressing the mixture between flows inside and outside the cavity.This results in a lower Overall Sound Pressure Level(OASPL) by 5~8 dB compared to the one in a cavity without doors and the frequency of the second Rossiter mode becomes higher,while the trend exhibits similar changes.In contrast,when the opening angles of stationary doors are larger(≥60°),shear layers over cavities are further away from the cavity floor than those in cases with smaller opening angles.The noise propagation is restricted in the spanwise direction,yielding higher OASPL(by 3~10 dB) at the cavity floor and amplified second Rossiter mode.OASPL for cavities with the opening of doors is comparable to those in a clean cavity.However,when the opening angle of moving doors is around 90°,the distribution of OASPL is similar to that in a cavity with stationary vertical doors.

关 键 词：内埋弹舱 嵌套重叠网格 非定常数值模拟 分离涡模拟 空腔噪声 经验模态分解 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]