B-spline curve fitting algorithm of airfoil blade surface
To obtain better airfoil blade surfaces and smoother fitting tool path curves,the discrete tool path of blade surfaces was reconstructed by B-spline curves based on the maximum equivalent lift.Using the continuous function relationship between the streamline position and the particle motion position variables,the relationship between the discrete tool path and the lift constraint based on the hydrodynamics characteristics was established.Taking the e-quivalent lift of the airfoil aerodynamic force on the airfoil as the constraint condition,the middle arc line was de-scribed by B-spline curve,and the discrete tool path based on the hydrodynamics characteristics was reconstructed by B-spline curve.The equivalent lift tool path was fitted under the minimum segmentation of curvature,endpoint interpolation,endpoint tangent vector continuity and maximum allowable error.The starfish discrete points and B-spline curve of plane cascade blade of subsonic compressor blade airfoil were selected for fitting simulation and pro-cessing,and the effectiveness of the algorithm was verified.The three-dimensional shape of blade surface processed by B-spline curve fitting was smoother and more uniform than that processed by straight line fitting,which could ob-tain lower residual height and higher surface quality.