An experimental investigation of the heat transfer due to multiple jets impinging normally on a dimpled surface

Abstract

A dimpled surface, used as a turbulence promoter, was combined with jet impingement to investigate the potential for heat transfer enhancement. An eight-by-eight jet array was used to impinge a staggered dimple surface, both on the dimples themselves and on the flat portions adjacent to the dimples. The heat transfer coefficient was measured using the transient wide-band liquid crystal method. The jet-to-plate spacing (H/D) studied was 2, 4 and 8. Two dimple geometries were tested: hemispherical concavities and cusped elliptical shapes. All the results were normalized by those from a flat plate. The results varied depending on the H/D spacing and the flow scheme for the exit (one-way, two-way and four-way exits); the effect of geometry variation (hemispherical or cusp shapes) was secondary. The maximum exit flow scheme (four-way exit) achieved the highest enhancement of heat transfer. The combination of dimples and impingement can lead to significant enhancement, but careful optimization of the location of impingement would be required.

Keywords

jet impingement dimple transient heat transfer liquid crystals

Get full access to this article

View all access options for this article.

References

Kesarev

V. S.

Kozlov

A. P.

Convection heat transfer in turbulized flow past a hemispherical cavity. Heat Transfer Res., 1993, 25 (2), 156–160.

Afanasyev

V. N.

Chudnovsky

Ya. P.

Leontiev

A. I.

Roganov

P. S.

Turbulent flow friction and heat transfer characteristics for spherical cavities on a flat plate. Expl Thermal and Fluid Sci., 1993, 7, 1–8.

Moon

H. K.

O'Connell

Glezer

Channel height effect on heat transfer and friction in a dimpled passage. ASME paper 99-GT-163, 1999.

Mahmood

G. I.

Hill

M. L.

Nelson

D. L.

Ligrani

P. M.

Local heat transfer and flow structure on and above a dimpled surface in a channel. In the ASME International Gas Turbine and Aeroengine Congress and Exhibition, Germany, 8–11 May 2000, paper 2000-GT-230.

Bearman

P. W.

Harvey

J. K.

Golf ball aerodynamics. Aeronaut. Q. May 1976, 112–122.

Chyu

M. K.

Ding

Downs

J. P.

Soechting

F. O.

Concavity enhanced heat transfer in an internal cooling passage. ASME paper 97-GT-437, 1997.

Gau

Chung

C. M.

Surface curvature effect on slot-air-jet impingement cooling flow and heat transfer process. J. Heat Transfer, 1991, 113, 858–864.

Cornaro

Fleischer

A. S.

Goldstein

R. J.

Flow visualization of a round jet impinging on cylindrical surfaces. Expl Thermal and Fluid Sci., 1999, 20, 66–78.

Camci

Kim

Hippensteele

S. A.

A new hue capturing technique for the quantitative interpretation of liquid crystal images used in convective heat transfer studies. J. Turbomach., 1992, 114, 765–775.

10.

Wang

Ireland

P. T.

Kohler

S. T.

Chew

J. W.

Heat transfer measurements to a gas turbine cooling passage with inclined ribs. J. Turbomach., 1998, 120, 63–69.

11.

Yuen

Martinez-Botas

R. F.

Film cooling characteristics of a single hole at various streamwise angles. Part 1: Effectiveness. Int. J. Heat and Mass Transfer, 2003, 46, 221–235.

12.

Yuen

Martinez-Botas

R. F.

Film cooling characteristics of a single hole at various streamwise angles. Part 2: Heat transfer coefficient. Int. J. Heat and Mass Transfer, 2003, 46, 237–249.

13.

Andrews

G. E.

Hussain

C. I.

Impingement cooling of gas turbine component. In the International Gas Turbine Congress and Exhibition, Tokyo, Japan, 1983.

14.

Obot

N. T.

Trabold

T. A.

Impingement heat transfer within arrays of circular jets: Part I-effects of minimum, intermediate and complete crossflow for small and large spacings. J. Heat Transfer, 1987, 109, 872–879.

15.

Huber

A. M.

Viskanta

Effect of jet-jet spacing on convective heat transfer to confined, impinging arrays of axisymmetric air jets. Int. J. Heat Mass Transfer, 1994, 37(18). 2859–2869.

16.

Babinsky

Edwards

J. A.

Automatic liquid crystal thermography for transient heat transfer measurements in hypersonic flow. Exp. Fluids, 1996, 21, 227–236.

17.

Gardon

Akfirat

J. C.

The role of turbulence in determining the heat-transfer characteristics of impinging jets. Int. J. Heat Mass Transfer, 1965, 8, 1261–1272.

18.

Goldstein

R. J.

Timmers

J. F.

Visualization of heat transfer from arrays of impinging jets. Int. J. Heat Mass Transfer, 1982, 25 (12), 1857–1868.

19.

Huber

A. M.

Viskanta

Convective heat transfer to a confined impinging array of air jets with spent air exits. J. Heat Transfer, 1994, 116, 570–576.

20.

Kline

S. J.

McClintock

F. A.

Describing uncertainties in single-sample experiments. Mech. Engng, January 1953, 3–8.

21.

Moon

H. K.

O'Connell

Sharma

Heat transfer enhancement using a convex-patterned surface. J. Turbomach., 2003, 125, 274–280.

22.

Van Treuren

K. W.

Wang

Ireland

P. T.

Jones

T. V.

Detailed measurements of local heat transfer coefficient and adiabatic wall temperature beneath an array of impinging jets. J. Turbomach., 1994, 116, 369–374.