A novel quasi-two-dimensional multi-streamline performance calculation method for transonic fans

Conventional one-dimensional mean-line methods struggle to accurately predict the performance of low hub-to-tip ratio transonic fans due to spanwise flow gradients, while two-dimensional methods are computationally costly and require excessive geometric parameters, making them unsuitable for preliminary design phases. This study proposes a quasi-two-dimensional multi-streamline approach that reduces both computational cost and geometric complexity relative to full through-flow solutions, without sacrificing radial flow resolution. By incorporating multiple streamlines under simplified radial equilibrium, it accounts for non-uniform radial distributions during preliminary design. Key innovations include a streamlined resettling algorithm, a stream tube choking model and flow redistribution scheme, and a meridional curvature correction scheme. Validation using single-stage and two-stage transonic fans shows that the method significantly improves prediction accuracy. Compared to traditional streamline curvature through-flow methods, it achieves about 100-fold speedup with the same number of streamlines and closely matches full three-dimensional computational fluid dynamics results in radial aerodynamic parameter distributions. This novel framework reconciles accuracy and computational efficiency, effectively addressing radial flow non-uniformities in the preliminary design phase. It streamlines the fan/compressor design process and enhances performance prediction reliability, offering significant advantages for high-performance turbomachinery development.