Experimental investigation of 2-D turning diffuser performance by varying inflow Reynolds Number

A turning diffuser is a kind of adapter used in the fluid flow system to recover surplus energy by converting kinetic energy to pressure energy. Nevertheless, minimal energy is commonly recovered as the flow within turning diffuser is often disrupted due to the nature of its geometry, leading to exc...

Full description

Saved in:
Bibliographic Details
Main Authors: Nordin, Normayati, Abdul Karim, Zainal Ambri, Othman, Safiah, Raghavan, Vijay R.
Format: Conference or Workshop Item
Published: 2013
Subjects:
Online Access:http://eprints.uthm.edu.my/4372/
http://eprints.uthm.edu.my/4372/1/Paper_30117_%2D_Camera_ready.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A turning diffuser is a kind of adapter used in the fluid flow system to recover surplus energy by converting kinetic energy to pressure energy. Nevertheless, minimal energy is commonly recovered as the flow within turning diffuser is often disrupted due to the nature of its geometry, leading to excessive losses. This paper aims to investigate the performance of 2-D turning diffuser by varying inflow Reynolds number (Rein). The outlet pressure recovery (Cp) and flow uniformity (σu) of 2-D turning diffuser with an area ratio of AR=2.16, operated at inflow Reynolds number of Rein= 5.786E+04-1.775E+05 have been experimentally tested. The experimental rig was developed incorporated with several features of low subsonic wind tunnel. This was mainly to produce a perfect fully developed and uniform flow entering diffuser. Particle image velocimetry (PIV) was used to examine the flow quality, and a digital manometer provided the average static pressure at the inlet and outlet of turning diffuser. The best produced pressure recovery of Cp=0.239 was recorded when the system was operated at maximum Rein=1.775E+05. However, the flow uniformity was considerably distorted, σu=6.12 with the increase of Rein Keywords- turning diffuser; flow uniformity; pressure recovery; particle image velocimetry (PIV) mainly due to secondary flow separation. A compromise between the maximum permissible pressure recovery and flow uniformity needs to be sought. The results obtained from this study will be in future used to validate the CFD codes. Several other configurations will be tested numerically in order to establish mathematical models.