An Experimental Study of Turbulent Flow and Heat Transfer in a Cooling Channel with Small V RibDimple Compound Structure

Abstract

Abstract:

Abstract： A structured surface with smallsized V ribs and dimples is a potentially highperformance cooling structure used for gas turbine blades. A comparative transient liquid crystal (TLC) transient experimental study was conducted to obtain the highresolution heat transfer characteristics and pressure loss in the cooling channels with different heights of Vshaped ribdimple in the Reynolds number range of 10 000 to 60 000. The results indicated that, under the condition of fully developed turbulent flow, the Nusselt number of the Vshaped ribdimple is 1.98 to 2.46 times of that of the smooth flat, with a friction factor of 2.24 to 4.36 times of that of the smooth flat. The Nusselt number of the Vshaped ribdimple is 1.21 to 1.76 times of that of circular dimples, with a friction factor of 1.96 to 3.89 times of that of circular dimples. Both the depth and Reynolds number of Vshaped rib can influence the flow field structure. The overall thermal performance factor of the Vshaped ribdimple with a depth of 0.6 and 1.0 mm is 4.7% to 12.8% higher than with a depth of 1.5 mm at a low Reynolds number (Re<20 000). With a continuous increase of the Reynolds number, the overall thermal performance of Vshaped ribdimple with a depth of 0.6 and 1.0 mm depth gradually decreases, but the overall thermal performance of Vshaped ribdimple with a depth of 1.5 mm gradually increases, and is 4.7% to 8.3% higher than that with the depths of 0.6 and 1.0 mm.

Key words: V rib, dimple, transient liquid crystal thermography (TLCT), convective cooling, gas turbine

CLC Number:

TK 124

XING Jianfeng1,RAO Yu1,LI Bo2,RAO Kun3. An Experimental Study of Turbulent Flow and Heat Transfer in a Cooling Channel with Small V RibDimple Compound Structure[J]. Journal of Shanghai Jiaotong University, 2017, 51(1): 40-.

References

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