Numerical Investigation on Mechanism and Modeling of Tip Leakage Flow Loss in Partially Shrouded Axial Flow Fans

The Partially Shrouded Axial-Flow Fan (PSAFF), extensively used in air conditioning and various industrial settings, exhibits a unique design wherein the shroud encompasses only a portion of the blade tips. However, there is a research gap in comprehending the tip leakage flow (TLF) behavior and developing more accurate loss models for PSAFF. The study addresses the gap by conducting numerical simulations on several structures with isolated fixed blades that replicate PSAFF’s blade tip design, and performing numerical simulations over diverse attack angles, shrouded ratios, and tip clearance heights, the paper elucidates how PSAFF’s structural intricacies significantly influence TLF’s flow pattern. The results underscore that the distinctive flow configuration profoundly affects TLF’s genesis and progression. Furthermore, pronounced disparities exist in the intensity and distribution of TLF loss in PSAFF compared to conventional fans. The straightforward application of prevailing axial compressor blade tip leakage flow loss models to the PSAFF leads to considerable prediction discrepancies. To remedy this, the study introduces tailored structural factors peculiar to PSAFF, in conjunction with traditional semi-empirical models. The new model effectively forecasts the total pressure loss coefficient and its fluctuation across different attack angle, marking a substantial progress in precisely predicting TLF loss in PSAFF and surmounting the constraints of current models.