2017年北航-清华-北大三校“歼十杯”博士生学术文化节即将于本周末在顺鑫绿色度假村举行。来自北京航空航天大学ld乐动体育官方网站的范月华同学和刘宏鹏同学将带来关于各自研究课题的宣讲。
范月华同学的报告题目是《Effects of steam ingestion on underfuselage inlet performance during a catapult-assisted take-off process》。
报告内容是：A naval aircraft has the potential to experience the inlet performance decline when taking off with the steam-driven catapult assistance. In this paper, the effects of the high-temperature steam ingestion on the inlet performance during the catapultassisted take-off process of an aircraft are numerically studied using the dual-time-step transient method with a real aircraft and inlet model being taken into account. The negative effects of the steam ingestion on the inlet performance mainly reflect in two aspects: the time-dependent rise and spatial distortion of the mass-averaged temperature on the inlet-exit. To investigate these negative effects, the flowfield characteristics of a designed baseline case are analyzed and the wind speed is studied by performing different numerical experiments. The analysis of the flowfield characteristics indicates that the engine’s suction effect and the aircraft's velocity are two key factors affecting the steam ingestion. The former factor is dominant at the beginning of the take-off since the aircraft's velocity is low, while the latter one is increasingly significant as the aircraft accelerates. The parametric studies show that the greater the wind speed is, the less significantly the flowfield of the inlet-exit would be affected by the steam.
刘宏鹏同学的报告题目是《Numerical Study on Influence of High Temperature Effects on Pitch Rotation Derivative for Hypersonic Reentry Vehicles》。
报告内容是：Influence of high temperature effects on pitch rotation derivative for hypersonic reentry vehicles is investigated numerically. Pitch rotation derivative is calculated with quasi-steady method based on solving the chemical reaction NavierStokes equations formulating in the rotating noninertial reference frame. Firstly, the simulation ability of numerical code is validated for the hypersonic flow around HB- 2 with high temperature effects. The computational results of the pressure along the wall agree well with the experiments. Secondly, the reliability of the quasi-steady method is verified by the comparision of the calculated results with experimental data for the dynamic derivatives of HBS configuration. Finally, the numerical experiments of the high temperature effects on pitch rotation derivative are performed based on HBS configuration with the hypersonic reentry condition. It is revealed that, although the chemical reacting gas model can greatly change the computational results of the pitching moments, the pitch rotation derivative calculated by the chemical reacting gas model is not more than 4% different from the calorically perfect gas results.
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