Abstract
Heat transfer from an open-wedge cavity to a symmetrically impinging slot air jet is investigated at the present study. The effect of the cavity angle was mainly examined on the Nusselt number distribution. Based on the results, heat transfer was generally poor at the vicinity of the apex, rising to form a maximum at the impingement and then followed by a moderate decline at further distances. The region of maximum heat transfer on the surfaces shifted outward the cavity as the cavity angle was decreased. Also, average Nusselt number over an effective length of the surface remained almost constant and independent of the cavity angle for a specified jet Reynolds number and nozzle-to-apex spacing.
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Abbreviations
- A :
-
Surface area of the plate (m2)
- h :
-
Distance from the nozzle exit to the apex of the cavity (m)
- h conv :
-
Convective heat transfer coefficient (W/m2 K)
- h o :
-
Natural convection coefficient (W/m2 K)
- I :
-
Electric current (A)
- k :
-
Thermal conductivity (W/m K)
- Nu :
-
Nusselt number (h conv w/k)
- q conv :
-
Heat transfer rate from the foil to the air jet (W/m2)
- q cond :
-
Heat transfer rate by conduction (W/m2)
- q gen :
-
Heat generation rate within the copper layer (W/m2)
- q rad :
-
Heat transfer rate from the plate by radiation (W/m2)
- Re :
-
Jet Reynolds number, uw/ν
- T :
-
Temperature (K)
- T ∞ :
-
Ambient air temperature (K)
- t :
-
Thickness of the plate (m)
- u :
-
Nozzle exit velocity (m/s)
- V :
-
Electric voltage (V)
- w :
-
Width of the rectangular nozzle (m)
- x :
-
Streamwise direction on the foil
- X :
-
Non-dimensional streamwise distance, x/w
- z :
-
Vertical direction (m)
- ε :
-
Emissivity of the foil
- θ :
-
Cavity angle
- σ :
-
Boltzmann constant
- pl :
-
Plastic sub-layer
- in :
-
Insulating layer
- i :
-
Plate surface element
References
Donaldson CD, Snedeker RS, Margolis DP (1971) A study of free jet impingement. Part 2. Free jet turbulent structure and impingement heat transfer. J Fluid Mech 45:477–512
Martin H (1979) Heat and mass transfer between impinging gas jets and solid surfaces. Adv Heat Transf 13:1–60
Zhou DW, Lee SJ (2007) Forced convective heat transfer with impinging rectangular slot jets. Int J Heat Mass Transf 50:1916–1926
Abdlmonem HB, Michel AS, Chandrakant DP (2000) The effect of inclination on the heat transfer between a flat surface and an impinging two-dimensional air jet. Int J Heat Fluid Flow 21:156–163
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
Song HB, Yoon SH, Lee DH (2000) Flow and heat transfer characteristics of a two-dimensional oblique wall attaching offset jet. Int J Heat Mass Transf 43:2395–2404
Eren H, Celik N (2006) Cooling of a heated flat plate by an obliquely impinging slot jet. Int Commun Heat Mass Transf 33:372–380
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
Faruque O, Brahma RK, Arora RC (1991) Impingement heat transfer from wedge surface. Wärme-und Stoffübertrag 26:175–179
Hossain A, Brahma RK (1993) Experimental investigations of fluid flow and heat transfer characteristics of a slot jet impinging on a square cylinder. Wärme-und Stoffübertrag 28:381–386
Rahimi M, Irani M (2012) Experimental study of slot jet impingement heat transfer on a wedge-shaped surface. Heat Mass Transf 48:2095–2101
Kline SJ, McClintock FA (1953) Describing uncertainties in single sample experiments. Mech Eng 75:3–8
Nirmalkumar M, Vadiraj K, Prabhu SV (2011) Local heat transfer distribution on a smooth flat plate impinged by a slot jet. Int J Heat Mass Transf 54:727–738
Gulati P, Katti V, Prabhu SV (2009) Influence of the shape of the nozzle on local heat transfer distribution between smooth flat surface and impinging air jet. Int J Therm Sci 48:602–617
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Rahimi, M., Mazraeh, A.E. Heat transfer from an open-wedge cavity to a symmetrically impinging slot air jet. Heat Mass Transfer 50, 1137–1143 (2014). https://doi.org/10.1007/s00231-014-1328-y
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DOI: https://doi.org/10.1007/s00231-014-1328-y