Mustafa TutarJanset Betul Cam2025-10-0620252504-186X10.3390/ijtpp10010001http://dx.doi.org/10.3390/ijtpp10010001https://gcris.yasar.edu.tr/handle/123456789/6638The present study introduces a conceptual design of a small axial-flow fan. Both individual and combined effects of blade stagger angle and winglet on the performance of the fan design are investigated in design and off-design operating conditions using a computational flow methodology. A stepwise solution in which a proper stagger angle adjustment of a specifically generated blade profile is followed by appending a winglet at the tip of the blade with consideration of different geometrical parameters is proposed to improve the performance characteristics of the fan. The initial model comparison analysis demonstrates that a three-dimensional Reynolds-averaged Navier-Stokes (RANS) equation-based renormalization group (RNG) k-epsilon turbulence modeling approach coupled with the multiple reference frame (MRF) technique which adapts multi-block topology generation meshing method successfully resolves the rotating flow around the fan. The results suggest that the use of a proper stagger angle with the winglet considerably increases the fan performance and the fan attains the best total efficiency with an additional stagger angle of +10 degrees and a winglet which has a curvature radius of 6.77 mm and a twist angle of -7 degrees for the investigated dimensioning range. The present study also underlines the effectiveness of passive flow control mechanisms of the stagger angle and winglets for energy-efficient axial-flow fans.Englishsmall axial-flow fan, aerodynamic performance, energy efficiency, flow control, computational fluid dynamics (CFD), multiple reference frame (MRF)AERODYNAMIC PERFORMANCE, NUMERICAL-SIMULATION, NOISEArticle