Analysis of numerical results for two-pass trapezoidal channel with different cooling configurations of trailing edge: The effect of dimples

Siddique, Waseem; Khan, Naveed Ahmed; Haq, Inamul

doi:10.1016/j.applthermaleng.2015.06.067

Cited by 15 publications

(2 citation statements)

References 19 publications

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“…Therefore, it is essential to have effective cooling technology to reduce the damage of the blades. Several cooling technologies in the past have been adopted in a turbine blade to increase heat transfer for both the internal and external blades, such as pin-fin cooling, rib-serpentine cooling, dimple cooling, film cooling, etc., as shown in Figure 1 [1][2][3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 96%

Effect of Rotation Number on Heat Transfer Characteristics of a Row of Impinging Jets in Confined Channel

Nontula

Kaewchoothong

Kaewapichai

et al. 2020

ARFMTS

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Jet impingement has been applied for internal cooling in gas turbine blades. In this study, heat transfer characteristics of impinging jets from a row of circular orifices were investigated inside a flow channel with rotations. The Reynolds number (Re) based on the jet mean velocity was fixed at 6,700. Whereas, the rotation number (Ro) of a channel was varied from 0 to 0.0099. The jet-to-impingement distance ratio (L/Dj) and jet pitch ratio (P/Dj) were respective 2 and 4, Dj is a jet diameter of 5 mm. The thermochromic liquid crystals (TLCs) technique was used to measure the heat transfer coefficient distributions on an impingement surface. The results show that heat transfer enhancement on a jet impingement surface depended on the effects of crossflow and Coriolis force. The local Nusselt number at X/Dj?20 on the leading side (LS) was higher than on the trailing side (TS) while heat transfer on the LS at 20?X/Dj?40 gained the lowest, compared to on the TS. The average Nusselt number ratios ( ) on the TS at Ro = 0.0049 gave higher than on the LS of around 2.17%. On the other hand, the on the TS at Ro = 0.0099 was less than the LS of about 0.08%.

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Section: Introductionmentioning

confidence: 96%

Effect of Rotation Number on Heat Transfer Characteristics of a Row of Impinging Jets in Confined Channel

Nontula

Kaewchoothong

Kaewapichai

et al. 2020

ARFMTS

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show abstract

“…It was concluded that the heat transfer improvement benefited from the secondary flow generated by the rib intersection. Siddique et al [23] arranged dimple structures on the endwalls of two-pass trailing edge channels, and discussed the effects of dimple arrangement on the heat transfer. In order to further improve the cooling performance in the trailing edge, composite cooling technologies based on various cooling methods have become a research hotspot.…”

Section: Introductionmentioning

confidence: 99%

Effects of Channel Outlet Configuration and Dimple/Protrusion Arrangement on the Blade Trailing Edge Cooling Performance

2019

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The trailing edge regions of high-temperature gas turbine blades are subjected to extremely high thermal loads and are affected by the external wake flow during operation, thus creating great challenges in internal cooling design. With the development of cooling technology, the dimple and protrusion have attracted wide attention for its excellent performance in heat transfer enhancement and flow resistance reduction. Based on the typical internal cooling structure of the turbine blade trailing edge, trapezoidal cooling channels with lateral extraction slots are modeled in this paper. Five channel outlet configurations, i.e., no second passage (OC1), radially inward flow second passage (OC2), radially outward flow second passage (OC3), top region outflow (OC4), both sides extractions (OC5), and three dimple/protrusion arrangements (all dimple, all protrusion, dimple–protrusion staggered arrangement) are considered. Numerical investigations are carried out, within the Re range of 10,000–100,000, to analyze the flow structures, heat transfer distributions, average heat transfer and friction characteristics and overall thermal performances in detail. The results show that the OC4 and OC5 cases have high heat transfer levels in general, while the heat transfer deterioration occurs in the OC1, OC2, and OC3 cases. For different dimple/protrusion arrangements, the protrusion case produces the best overall thermal performance. In conclusion, for the design of trailing edge cooling structures with lateral slots, the outlet configurations of top region outflow and both sides extractions, and the all protrusion arrangement, are recommended.

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Thermo-hydraulic performance of rectangular channel roughened with combined semi-circular and triangular ribs

2019

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Analysis of numerical results for two-pass trapezoidal channel with different cooling configurations of trailing edge: The effect of dimples

Cited by 15 publications

References 19 publications

Effect of Rotation Number on Heat Transfer Characteristics of a Row of Impinging Jets in Confined Channel

Effect of Rotation Number on Heat Transfer Characteristics of a Row of Impinging Jets in Confined Channel

Effects of Channel Outlet Configuration and Dimple/Protrusion Arrangement on the Blade Trailing Edge Cooling Performance

Thermo-hydraulic performance of rectangular channel roughened with combined semi-circular and triangular ribs

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