Iranian Journal of Mechanical Engineering Transactions of ISME

Iranian Journal of Mechanical Engineering Transactions of ISME

Experimental study of diffuser effect on the fan performance

Author
Mohammad Ali Ardekani
Abstract
Axial flow fans, in open circuit suction wind tunnels, discharge air into the ambient. This discharge of air causes large energy dissipation, proportional to the third power of air flow velocity. In order to reduce this energy wastage, a diffuser at the fan downstream can be used. Consequently, it becomes necessary to determine the effect of diffuser on the fan’s performance. In this experimental investigation, a fan test bed has been constructed on the basis of ISO 5801 Standard, and the fan’s characteristic curve has been measured with and without the diffuser. In addition, a 7.8% model of the diffuser has been evaluated and pressure distribution along the diffuser and velocity distribution at the diffuser exit have been measured using a wind tunnel. Results show that separation phenomenon does not occur in the diffuser. For a diffuser, with an exit to inlet cross section area ratio of 2:1, installed at the fan’s downstream, air flow rate and static pressure show 10% and 25% increase, respectively. The fan’s power consumption does not show appreciable variation, and hence, fan’s performance, with the diffuser installed, shows a 35% improvement.
Keywords
Fan
Diffuser
Characteristic curve
Wind Tunnel
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Iranian Journal of Mechanical Engineering Transactions of ISME
Volume 15, Issue 2 - Serial Number 31
Fluid Mechanics and Heat Transfer
Summer 2013
Pages 24-42

  • Receive Date 23 August 2013