扰流片对无尾飞行器气动特性影响分析

为了研究扰流片偏转对示例飞行器气动特性的影响,建立了用于分析整机流场的计算流体力学(CFD)方法。设定扰流片偏转角度为0°、22°和45°,并在给定迎角范围内对飞机的流场特征进行求解。结果表明,开启扰流片可明显改变机翼上表面的静压,而随着开启角度的增加,升力损失在大部分迎角下是存在的,在个别迎角下,增加扰流片开启角度可少量提高升力系数。当扰流片偏转角度给定时,阻力系数随着迎角的增加总体上表现出增加趋势。在示例的大部分迎角下,扰流片开启角度的增加将导致侧力系数减小。

中国成功攻克涡扇发动机反推力风洞试验技术

中国首次TPS反推力试验日前在中国空气动力研究与发展中心低速所8m×6m风洞圆满完成。这标志着中国从此具备TPS正反推力风洞试验能力,对中国飞行器尤其是大型飞机的研制具有重要意义。TPS英文全称为Turbofan-Poered-Simulator,即涡扇动力模拟,是大型涡扇发动机必须进行的一项试验。

Study on Lateral Aerodynamic Characteristics of Hypersonic Lifting-Configuration

To have a deep understanding of the lateral stability of hypersonic lifting-configurations, wind-tunnel tests of roll static and dynamic stability for typical hypersonic lifting-configurations are carried out. The results show the roll is static unstable in small angles; the roll dynamic test curves present obvious non-linearity characteristics, and the model vibrates violently even When the angle of attack is small, which may be provoked by the non-symmetry transition from the small transverse flow around the nose of model. Subsequent research adopts longitudinal trips to generate symmetry transition at the fore-body of the model. As a result, the lateral stability of the aircrafts is apparently improved. The results show that the lateral stability of hypersonic aircrafts is very weak, and the main reason for this is lateral perturbation of flow over the nose, among which asymmetric transition weighs the most. Adoption of longitudinal trips could spur fixed transition of lateral flow, reduce the transition asymmetry of lateral flow, and strengthen the lateral stability of hypersonic aircrafts at the same time.

现代试验设计方法在高速风洞试验中的应用

为了验证现代试验设计(MDOE)方法在高速风洞试验中应用的可行性,进一步提高风洞试验效率,采用区组化的回归组合设计进行了某运输类飞机亚声速基本纵向常规测力风洞试验,通过少量关键控制点数据建立了气动力参数随马赫数和迎角变化的二阶响应面模型,并进行了方差分析及显著性检验。同时,通过额外增加的试验点检验响应面模型的精准度。试验及分析结果表明:通过回归组合设计少量试验点建立的纵向气动力系数响应面模型预测误差满足高速风洞飞机模型测力试验精度指标要求,方差分析(ANOVA)及显著性检验结果正确反映了迎角、马赫数对飞行器基本气动特性的影响规律,突显出MDOE方法应用于风洞试验方案设计及数据分析的显著优势。