An experimental and numerical investicration on a confined impinging air jet at high Reynolds numbers


Baydar E. , OZMEN Y.

APPLIED THERMAL ENGINEERING, cilt.25, ss.409-421, 2005 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

An experimental and numerical study is carried out to investigate flow field of a confined jet issuing from the lower surface and impinging normally on the upper surface. The mean velocity, turbulence intensity and pressure distributions in the impingement re-ion were obtained for Reynolds numbers ranging from 30,000 to 50,000 and a nozzle-to-plate spacing range of 0.2-6. The effects of Reynolds number and nozzle-to-plate spacing on the flow structure are examined. A subatmospheric region occurs on the Impingement plate at nozzle-to-plate spacings up to 2 for Reynolds numbers studied and it moves radially outward from the stagnation point with increasing nozzle-to-plate spacing. It is concluded that there exists a linkage among the subatmospheric region, turbulence intensity and heat transfer coefficients. The numerical results obtained using the standard k-epsilon turbulence model are in agreement with the experimental results except for the nozzle-to-plate spacings less than one. (C) 2004 Elsevier Ltd. All rights reserved.