2.4 m连续式跨声速风洞大飞机精细化测力试验技术

Precision force measurement techniques for large aircraft models in 2.4 m continuous transonic wind tunnel

为满足大飞机研制对风洞测力试验数据精准度的需求,并适应2.4 m连续式跨声速风洞运行特点,中国航空工业空气动力研究院成功研发了多项精细化的测力试验技术。这些技术中,低热膨胀系数高强度天平和天平温度效应补偿与修正技术有效地减小了温度变化对天平数据的影响;角度传感器和视频相结合的直接测量方法与改进后的角度叠加测量方法,均提高了模型姿态角的测量精度;基于线性回归的天平初始载荷计算方法可以一次性获得各种试验状态下的天平初始载荷,并提高气动载荷计算的准确性;基于前后置减振器的主动振动抑制技术能降低模型振动对测量数据的干扰并拓宽迎角范围;弹性变形视频测量与CFD修正技术可以有效分离高雷诺数试验结果中的弹性变形对气动力的影响量。本文对这些试验技术的原理进行了详细介绍,并给出案例证明这些试验技术能够有效提高测力试验的精准度;与ETW风洞的对比试验显示,大展弦比民机模型的升力系数偏差约0.002,阻力系数偏差约0.000 2。

To meet the stringent demand for the precision and accuracy in wind tunnel force testing of large aircraft models,Aerodynamics Research Institute of AVIC(Aviation Industry Corporation of China)has innovated several cutting-edge force measurement techniques tailored for the 2.4 m continuous transonic wind tunnel.These techniques include a high-strength and low-thermal-expansion-coefficient balance with the temperature compensation and correction,an attitude angle measurement method using angle sensors and video and a modified method for measuring the attitude angle superposition,a fast calculation method of the initial balance loads under various test conditions based on the linear regression,an active anti-vibration technique based on front and rear damping systems that broadens the range of attack angle,video measurement and CFD(Computational Fluid Dynamics)simulation integrated elastic deformation correction method that effectively isolates the effects of elastic deformation on the aerodynamic forces in high-Reynolds-number tests.This paper delves into the principles underlying these innovative testing techniques and demonstrates their efficacy through case studies.Compared to the European Transonic Windtunnel,our techniques have achieved remarkable improvements in accuracy,with deviations of lift and drag coefficients for a large aspect ratio civil aircraft model being only 0.002 and 0.0002,respectively.These advancements represent a significant step forward in ensuring the reliability and accuracy of wind tunnel testing for large aircraft models.