Development of Mixed Flow Fans with Bio-Inspired Grooves.

Jinxin Wang,Hao Liu,Toshiyuki Nakata

doi:10.3390/biomimetics4040072

Jinxin Wang, Hao Liu + Show 1 more

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https://doi.org/10.3390/biomimetics4040072

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Abstract

Mixed flow fan is a kind of widely used turbomachine, which has faced problems of further performance improvement in traditional design methods in recent decades. Inspired by the microgrooves such as riblets and denticles on bird feathers and shark skins, we here propose biomimetic designs of various blades with the bio-inspired grooves, aiming at the improvement of the aeroacoustic performance. Based on a systematic study with computational fluid dynamic analyses, we found that these designs had the potential in noise suppression even with macroscopic grooves. Our best design can suppress turbulence kinetic energy by approximately 38% at the blade leading edge with aerodynamic efficiency loss of only 0.3 percentage points. This improvement is achieved by passive flow control. The vortical structures are changed in a favorable way at the leading edge due to the grooves. We believe that these biomimetic designs could provide a promising future of enhancing the performance of mixed flow fans by making grooves of ideal flow passages on the suction faces of blades in accord with the theory of pump design.

Highlights

Mixed flow fan is widely used for the ventilation in industries and it is a kind of centrifugal pump or turbomachine which has been developed for centuries [1]
We demonstrate that the proposed fan design does show potential in suppressing noise though with marginal aerodynamic loss, and that the biomimetic design could provide a useful and effective method to improve the aeroacoustic performance of mixed flow fans
We explored the effects of different accordance with the ideal flow assumption in pump theory

Summary

Introduction

Mixed flow fan is widely used for the ventilation in industries and it is a kind of centrifugal pump or turbomachine which has been developed for centuries [1]. Where, the n denotes rotational speed (rpm), Q denotes the volume flow rate (m3 /s) and Hpump (m) denotes the head of the pump (the dimension of ns is same to g3/4 (g: gravity acceleration)) [2]. The industrial flow fans require improvement on the fluid dynamic performance and the working stability associated with the vibrations, noise, and unnecessary forces [3]. To this end, recent studies on the industrial pump mainly focus on the effects of its traditional design parameters on the fluid dynamic output or pressure fluctuations [4,5,6,7,8].

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