DocumentCode :
3188256
Title :
Improved predictions of the flow field in submerged and confined impinging jets using the Reynolds stress model
Author :
Morris, Garron K. ; Garimella, Suresh V. ; Fitzgerald, Janice A.
Author_Institution :
Dept. of Mech. Eng., Wisconsin Univ., Milwaukee, WI, USA
fYear :
1998
fDate :
27-30 May 1998
Firstpage :
362
Lastpage :
370
Abstract :
The flow field of a normally impinging, axisymmetric, confined and submerged liquid jet is predicted using the Reynolds stress turbulence closure model in the FLUENT finite-volume code. The results are compared with experimental measurements and flow visualizations, and are used to describe the position of the recirculating toroid in the outflow region which is characteristic of the confined flow field. Changes in the recirculation pattern features due to changes in Reynolds number, nozzle diameter and nozzle-to-target plate spacing are documented. Results are presented for nozzle diameters of 3.18 and 6.35 mm, jet Reynolds numbers in the 2000-23000 range, and nozzle-to-target plate spacings of 2, 3, and 4 jet diameters. Up to three interacting vortical structures are predicted in the confinement region at the smaller Reynolds numbers. The primary recirculation pattern center moves away from the jet center line with an increase in Reynolds number, nozzle diameter, and nozzle-to-target plate spacing. Computed flow patterns were in very good qualitative agreement with experiments. The radial location of the primary toroid center was predicted to within ±40% and ±3% of the experimental position for Re=2000-4000 and Re=8500-23000, respectively. The jet center line velocity after the nozzle exit was computed with an average error of 6%. Reasons for the differences between the numerical predictions at Re=2000-4000 and experiments are discussed. Flow field predictions using the standard high-Reynolds number k-ε and renormalization group theory (RNG) k-ε models are shown to be inferior to Reynolds stress model predictions
Keywords :
confined flow; cooling; error analysis; finite volume methods; flow visualisation; jets; laser velocimetry; nozzles; renormalisation; stress analysis; thermal management (packaging); turbulence; vortices; 3.18 mm; 6.35 mm; FLUENT finite-volume code; Reynolds number; Reynolds stress model; Reynolds stress model predictions; Reynolds stress turbulence closure model; axisymmetric confined submerged liquid jet; computed flow patterns; confined flow field; confined impinging jets; confinement region; flow field; flow field prediction; flow visualization; interacting vortical structures; jet Reynolds number; jet center line; jet center line velocity; jet center line velocity computation error; jet impingement cooling; laser Doppler velocimetry; normally impinging liquid jet; nozzle diameter; nozzle exit; nozzle-to-target plate spacing; numerical prediction; outflow region; primary recirculation pattern center; radial primary toroid center location; recirculating toroid position; recirculation pattern features; renormalization group theory models; standard high-Reynolds number models; submerged impinging jets; Electronics cooling; Fluid dynamics; Fluid flow measurement; Heat transfer; Mechanical engineering; Predictive models; Stress; Thermal management of electronics; Viscosity; Visualization;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Thermal and Thermomechanical Phenomena in Electronic Systems, 1998. ITHERM '98. The Sixth Intersociety Conference on
Conference_Location :
Seattle, WA
ISSN :
1089-9870
Print_ISBN :
0-7803-4475-8
Type :
conf
DOI :
10.1109/ITHERM.1998.689588
Filename :
689588
Link To Document :
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