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

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.