曲率连续的非轴对称短舱气动型面参数化设计方法研究

In order to improve the internal and external performance of nacelle, the parametric design method for the aerodynamic profiles of continuous curvature non-axisymmetric nacelle, based on Class Shape Transformation function, was developed. To evaluate the parametric design method for the aerodynamic profiles of non-axisymmetric nacelle, the curvature radius distribution, flow characteristics, and aerodynamic performance of the ultra-high bypass ratio turbofan nacelle designed by the method developed in this paper and designed by the method based on conic curve were compared. In comparison to the nacelle designed by the method based on the conic curve, there is no fluctuation in the distribution of curvature radius in the axial direction for the nacelle by the method developed in this paper. The local drag around the maximum area cross-section of the nacelle designed by the method developed in this paper decreases by 4.5% in cruise condition, that free stream Mach number is 0.8 and decreases by 5.5% in the condition that the free stream Mach number is 0.82. The reason for this is that the local high-velocity zone caused by fluctuations in the curvature radius around the maximum area cross-section of the cowl is avoided. Compared with the nacelle designed by the method based on the conic curve, the total pressure recovery coefficient of intake increases by 0.41% and the steady circumferential distortion index of total pressure decreases by 8.82% in climb condition with high angle of attack, due to the improved design method of intake.