尾支撑对CHN-T2模型翼身连接区域分离涡影响

Influence of tail support on separation vortex in wing-body junction region of CHN-T2 model

关键词:  尾支撑  CHN-T2  翼身连接区域  分离涡  支撑干扰

Key words:  tail support  CHN-T2  wing-body junction region  separation vortex  support interference

摘要:

为探究CHN-T2风洞试验中尾支撑添加前、后模型气动力特性出现局部跳跃现象的规律及其形成机制,以便后续类似风洞试验中尾支撑结构的选型及试验数据支撑干扰修正参考,采用国家数值风洞工程资助开发的数值模拟软件NNW-FSI,对CHN-T2翼/身/平尾/立尾组合体构型（计算条件为马赫数为0.85、攻角为-5°~10°）尾支撑对局部流动结构的影响进行了数值模拟研究。首先,通过开展CHN-T2模型数值模拟仿真,并将气动力计算数据与试验数据进行对比,验证了计算数据的可靠性。其次,基于有、无尾支撑的计算数据分析了尾支撑对CHN-T2模型气动特性的影响规律,并确定了气动特性发生跳跃的攻角区间。最后,对5°攻角下的结果进行了详细分析,包括翼身连接区域局部流线及分离涡、机翼展向剖面压力分布和机尾局部流动结构、机尾支撑对机尾压力分布的影响规律和机制。分析结果表明,在特定飞行马赫数和攻角区间,尾支撑会对机尾产生局部流动干扰并向前传播,提高翼根后缘处的压力,抑制翼根后缘的流动分离,消除CHN-T2翼身连接区域的分离涡,从而改变了CHN-T2模型的气动特性。

Abstract:

This paper aims to investigate the patterns and formation mechanisms of localized jump phenomena in aerodynamic characteristics before and after adding tail supports in the CHN-T2 wind tunnel experiments, thereby providing references for the selection of tail support structures and support interference correction of experimental data in subsequent similar wind tunnel experiments. The numerical simulation software NNW-FSI, developed with funding from national numerical wind tunnel project, was employed to conduct numerical simulation research on the influence of tail supports on local flow structures for the CHN-T2 wing/body/horizontal tail/vertical tail combination configuration (under computational conditions of Mach number of 0.85 and angle of attack ranging from -5° to 10°). First, the reliability of the computational data was verified by conducting numerical simulations of the CHN-T2 model and comparing the calculated aerodynamic data with experimental data. Subsequently, based on computational data with and without tail support, the patterns of tail support’s influence on the aerodynamic characteristics of the CHN-T2 model were analyzed, and the angle-of-attack range where a jump occurred in the aerodynamic characteristics was identified. Finally, a detailed analysis was performed on the results at a 5° angle of attack, including local streamlines and separation vortices in the wing-body junction region, spanwise sectional pressure distributions of the wing, local flow structures near the tail, and the patterns and mechanisms of tail supports influence on tail pressure distribution. The analysis results show that within specific flight Mach numbers and angle-of-attack ranges, the tail support induces localized flow interference near the tail, which propagates forward, increasing pressure at the trailing edge of the wing root, suppressing flow separation there, and eliminating the separation vortex in the wing-body junction region of CHN-T2. Consequently, these effects alter the aerodynamic characteristics of the CHN-T2 model.