Abstract
Experimental measurements for the local variation of effectiveness, pressure and Nusselt number for straight and inclined slot jets impinging on a convex cylindrical surface are reported in this study. The curvature ratio, defined as the ratio of slot width to diameter of impingement target surface (b/D) was kept constant at 0.045. Data are reported for Reynolds number, based on the velocity of the jet and width of the slot, equal to 8500 for jets inclined at 0°, 30° and 45° to the jet axis. The non dimensional distances between jet exit and convex surface (H/b) equal to 4, 6, 8 and 10 were studied. The results show that the effectiveness increases on the downhill side but exhibits a rapidly decreasing trend on the uphill side with increase in inclination angle. The maximum pressure coefficient and Nusselt number shifts towards the uphill side for obliquely impinging jets. Detailed distributions of effectiveness and Nusselt number show that the entrainment from the top and bottom edges of the jet after impingement penetrates inwards causing an effectiveness variation along slot height direction at large circumferential distance from impingement point and increases heat transfer at those positions by increasing the turbulence.
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Abbreviations
- Afoil :
-
Area of foil, m2
- b:
-
Width of slot, m
- Cp:
-
Coefficient of pressure, (P − Pamb)/(0.5ρU2)
- D:
-
Diameter of convex surface, m
- d:
-
Diameter of circular jet tube, m
- H:
-
Jet- to-plate distance, m
- h:
-
Heat transfer coefficient, W/m2K
- I:
-
Current, A
- k:
-
Thermal conductivity of air, W/mK
- Nu:
-
Nusselt number, hb/k
- P:
-
Pressure, Pa
- q:
-
Heat transfer, W
- q″:
-
Heat flux, W/m2
- Re:
-
Reynolds number, ρUb/μ
- r:
-
Direction along convex surface
- T:
-
Temperature, K
- U:
-
Average exit velocity of jet, m/s
- V:
-
Voltage, V
- y:
-
Direction along slot height
- amb:
-
Ambient
- aw:
-
Adiabatic
- j:
-
Jet
- loss:
-
Loss
- total:
-
Total
- w:
-
Wall
- θ:
-
Inclination of impinging surface with jet center line
- η:
-
Effectiveness
- ρ:
-
Density of air
- μ:
-
Dynamic viscosity of air
References
Gau C, Chung CM (1991) Surface curvature effect on slot-air-jet impingement cooling flow and heat transfer process. J Heat Transf 113:858–864
Lee DH, Chung YS, Kim DS (1997) Turbulent flow and heat transfer measurements on a curved surface with a fully developed round impinging jet. Int J Heat Fluid Flow 18:160–169
Lim KB, Lee CH, Sung NW, Lee SH (2007) An experimental study on the characteristics of heat transfer on the turbulent round impingement jet according to the inclined angle of convex surface using the liquid crystal transient method. Exp Thermal Fluid Sci 31:711–719
Chan TL, Leung CW, Jambunathan K, Ashforth-Forst S, Zhou Y, Liu MH (2002) Heat transfer characteristics of a slot jet impinging on a semi-circular convex surface. Int J Heat Mass Transf 45:993–1006
Schuh H, Persson B (1964) Heat transfer on circular cylinders exposed to free jet flow. Int J Heat Mass Transf 7:1257–1271
Beltaos S (1976) Oblique impingement of circular turbulent jets. J Hydraul Res 14(1):17–36
Akansu YE, Sarioglu M, Kuvvet K, Yavuz T (2008) Flow field and heat transfer characteristics in an oblique slot jet impinging on a flat plate. Int Commun Heat Mass Transf 35:873–880
Goldstein RJ, Sobolik KA, Seol WS (1990) Effect of entrainment on the heat transfer to a heated circular air jet impinging on a flat surface. J Heat Transf 112:608–611
Hollworth BR, Wilson SI (1984) Entrainment effects on impingement heat transfer: part I-measurements of heated jet velocity and temperature distributions and recovery temperatures on target surface. J Heat Transf 106:797–803
Fenot M, Vullierme JJ, Dorignac E (2005) A heat transfer measurement of jet impingement with high injection temperature. C. R. Mecanique 333:778–782
Abraham S, Kakade AB, Vedula RP (2015) Convex surface heat transfer behaviour in the presence of obliquely impinging non-isothermal slot jets. In: Lecture notes in engineering and computer science: proceedings of the World Congress on Engineering 2015 (WCE 2015), London, UK, pp 1273–1278, 1 July–3 July 2015
Coleman HW, Steele WG Jr (1989) Experimentation and uncertainty analysis for engineers. Wiley, New York
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Abraham, S., Kakade, A.B., Vedula, R.P. (2016). Heat Transfer Performance for an Obliquely Impinging Slot Jet on a Convex Surface. In: Ao, Si., Yang, GC., Gelman, L. (eds) Transactions on Engineering Technologies. Springer, Singapore. https://doi.org/10.1007/978-981-10-1088-0_9
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DOI: https://doi.org/10.1007/978-981-10-1088-0_9
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