Refined Aerodynamic Test of Wide-Bodied Aircraft and Its Application

The large dual-channel wide-bodied aircraft has a long range and a high cruise Mach number. Therefore, its aerodynamic design requires a high level of wind tunnel test refinement. Based on the requirements of aerodynamic design for the future wide-bodied aircraft and the characteristics of high-speed wind tunnel tests, the error theory is introduced to analyze the factors affecting the accuracy of the test data. This study carries out a series of research on the improvement of refined aerodynamic test technology in an FL-26 wind tunnel, including design and optimization of the support system of wide-bodied aircraft, model attitude angle measurement, Mach number control accuracy, measurement and control system stability, test data correction and perfection, high-precision force balance and standard model development. In addition, the effect of the standard specification of the refined aerodynamic test is investigated to improve the data quality. The research findings have been applied in the standard model test and subsequent models of wide-bodied aircraft. The results show that when Mach numbers are less than 0.9, the control accuracy of Mach numbers in the FL-26 wind tunnel is smaller than 0.001 and the measurement error of attack angle is smaller than 0.01°. Therefore, it has the ability to correct the data influenced by factors, such as support/wall interference, model deformation, floating resistance and airflow deflection angle. The repeatability accuracy of the standard model’s comparison test shows that the lift coefficient is less than or equal to 0.0012, the drag coefficient is less than or equal to 0.00004, pitching moment coefficient is less than or equal to 0.0004. The bending resolution of the model’s deformation measurement is less than 0.2 mm, and the tensional deformation is smaller than 0.04°. The revised aerodynamic data and model deformation measurement results have good agreement with that of the ETW wind tunnel. The results demonstrate that the improved technology presented in this paper can significantly enhance the refined aerodynamic test of wide-bodied aircraft.