Title: Reynolds stress statistics in the near nozzle region of coaxial swirling jets

Authors: Viacheslav Stetsyuk; John Chai Chee Kiong

Addresses: School of Computing and Engineering, University of Huddersfield, UK ' School of Computing and Engineering, University of Huddersfield, UK

Abstract: Particle image velocimetry was used to obtain the mean axial u and radial v velocities and the Reynolds stress statistics ‹u'_iu'_j› in an isothermal swirling jet. The flow Reynolds number was 29,000. The effects of the swirl number on the behaviours of the Reynolds stresses, and their gradients are analysed. The results show pronounced asymmetry in the mean and the fluctuating quantities for all swirl numbers. The flow asymmetricity is found to be related to the radial velocity fluctuations. The ratio of u'²√v'² was found to be circa 0.5 and was independent of the flow swirl number. The values of u'v' were circa 5%-10% of v'². It was postulated that for swirling flows with constant Reynolds number the change in the flow swirl number only, does not necessary result in increase of turbulent intensity. An 'effective' turbulent viscosity was shown to be independent of the flow swirl number for constant Reynolds number.

Keywords: Reynolds stress; swirling jet; Reynolds-averaged Navier-Stokes; RANS; coaxial.

DOI: 10.1504/IJHM.2018.094886

International Journal of Hydromechatronics, 2018 Vol.1 No.3, pp.332 - 349

Received: 28 May 2018
Accepted: 02 Jul 2018
Published online: 25 Sep 2018 *

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