Laser powder bed fusion enabled modular fan blade design for efficient acoustic optimization

Abstract Additive manufacturing’s design freedom enables new approaches to component modularity that were previously constrained by traditional manufacturing methods. This research presents such an application in aeroacoustic research, where the acoustic emission of fans operating under disturbed inflow conditions remains a critical factor in the acceptance of Heating, Ventilation and Air Conditioning (HVAC) systems. While leading-edge modifications such as serrations, slits, or porous structures have shown noise reduction potential, research into different variants has been costly due to the need to manufacture complete blade sets for each design iteration. This study presents a modular research fan blade design featuring an interchangeable leading edge manufactured using powder bed fusion laser beam (PBF-LB) technology. The modular design utilizes a stepped-cut interface at one-third of the chord length at the fan tip, with manufacturing tolerances systematically optimized to achieve minimal gap dimensions at the blade interface while maintaining mechanical reliability through lateral screw fixation. Experimental validation using a fan test rig compliant with DIN 5801 confirmed that the modular configuration maintains equivalent performance to a monolithic reference fan of identical geometry. Both aerodynamic and acoustic measurements showed close agreement across all operating points, with static pressure rise deviations below 2 Pa within the design operating range (maximum 4 Pa in the partial load region) and acoustic deviations within ±0.5 dB(A). Spectral analysis confirmed no introduction of tonal components. This platform provides a foundation for systematic investigation of noise reduction technologies in axial-fan applications.