Effect of bleed hole on internal flow and heat transfer in matrix cooling channel

Sun, Haiou; Sun, Tiezhi; Yang, Lianfeng; Bu, Shi; Luan, Yigang

doi:10.1016/j.applthermaleng.2018.03.031

Cited by 18 publications

(6 citation statements)

References 28 publications

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“…C f is calculated using the expression (21). It is directly proportional to the drag friction force, F f .…”

Section: The Spatial Effect Of Rib In Channelmentioning

confidence: 99%

“…The matrix cooling channel is relatively better in augmenting heat transfer compared to ribbed and dimpled channels but at the cost of a large pressure drop. 21…”

Section: Introductionmentioning

confidence: 99%

“…The matrix cooling channel is relatively better in augmenting heat transfer compared to ribbed and dimpled channels but at the cost of a large pressure drop. 21 Meanwhile, according to Liang et al, flow through FCC (face-centered cubic) lattices structure with circular shape is higher than elliptical and rectangular-shaped latticed based on the Nusselt number 27%-31% and 25%226% higher, respectively. Even though the circular lattice reportedly has the lowest heat transfer performance, the overall heat transfer efficiency is the highest due to the lowest pressure drop.…”

Section: Introductionmentioning

confidence: 99%

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Spatial effect of a vertical multi-faceted rib on thermal performance and flow characteristics in a square channel

Amir

Ir.

2022

Proceedings of the Institution of Mechanical Engineers, Part C:

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A multi-faceted vertical rib has been numerically investigated using the internal flow of rib in a rectangular channel method under turbulent flow for 17,000 < Re < 27,000. The vertical rib that can be encountered inside porous media design often creates a persisting issue of high-pressure drop. The challenge frequently intensifies, mainly when a two-phase state heat transfer is introduced inside the porous media. The vertical multi-faceted rib models the various surfaces often encountered inside the porous media. The effect of blockage ratio on the flow characteristics and thermal performance is observed. The results are compared to the more conventional circular rib, equal in surface area to the multi-faceted rib. The multi-faceted rib yields a higher average Nusselt number of approximately 33% and contributes to the higher average Nusselt number of the channel. The multi-faceted rib channel has a better thermal performance factor, in average of approximately 13% higher and lower pressure drop than the circular rib channel. The advantage of the multi-faceted rib is attributed to, surprisingly, the poor flow attachment on the rib surface, which results in a low Cf/ f ratio. Consequently, the multi-faceted rib suffers from very low velocity on the downstream rib surface. Ultimately, the spatial effect of the rib inside the square channel can be evaluated using the Cf/ f ratio, which takes into account the rib surface and channel walls. In the quasi two-phase state, the circular rib is observed to provide a more favorable condition for latent heat transfer under extreme condition investigated.

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“…C f is calculated using the expression (21). It is directly proportional to the drag friction force, F f .…”

Section: The Spatial Effect Of Rib In Channelmentioning

confidence: 99%

“…The matrix cooling channel is relatively better in augmenting heat transfer compared to ribbed and dimpled channels but at the cost of a large pressure drop. 21…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Spatial effect of a vertical multi-faceted rib on thermal performance and flow characteristics in a square channel

Amir

Ir.

2022

Proceedings of the Institution of Mechanical Engineers, Part C:

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“…Although some potential internal cooling designs have been presented with the rise of casting technology, such as matrix cooling [3,4] and double-wall cooling [5], the conventional method, jet impingent cooling, is still the most widely used for the protection of blade leading edge because of its intense unsteady disturbance and high local heat transfer coefficient [6]. A vast number of reviews of impingement cooling exist, such as Refs.…”

Section: Introductionmentioning

confidence: 99%

Cooling Characteristic of a Wall Jet for Suppressing Crossflow Effect under Conjugate Heat Transfer Condition

Deng

Feng

2022

Aerospace

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The leading edge is the critical portion for a gas turbine blade and is often insufficiently cooled due to the adverse effect of Crossflow in the cooling chamber. A novel internal cooling structure, wall jet cooling, can suppress Crossflow effect by changing the coolant flow direction. In this paper, the conjugate heat transfer and aerodynamic characteristics of blades with three different internal cooling structures, including impingement with a single row of jets, swirl cooling, and wall jet cooling, are investigated through RANS simulations. The results show that wall jet cooling combines the advantages of impingement cooling and swirl cooling, and has a 19–54% higher laterally-averaged overall cooling effectiveness than the conventional methods at different positions on the suction side. In the blade with wall jet cooling, the spent coolant at the leading edge is extracted away through the downstream channels so that the jet could accurately impinge the target surface without unnecessary mixing, and the high turbulence generated by the separation vortex enhances the heat transfer intensity. The Coriolis force induces the coolant air to adhere to the pressure side’s inner wall surface, preventing the jet from leaving the target surface. The parallel cooling channels eliminate the common Crossflow effect and make the flow distribution of the orifices more uniform. The trailing edge outlet reduces the entire cooling structure’s pressure to a low level, which means less penalty on power output and engine efficiency.

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“…The results show that the heat transfer uniformity can be improved by adding sidewall slots; the heat transfer performance of channels with arc slots is better than that with rectangular slots; both the heat transfer enhancement and pressure loss increase with the pin fin diameter but simply increasing the pin fin number has no benefit on the heat transfer enhancement; and the sidewall turning regions are better places than the subchannel mid-parts to place the pin fins. Sun et al 9 numerically studied the performance of matrix cooling channels with and without bleeding holes. The authors found that the bleeding holes can improve local heat transfer by extracting the corner vortexes near the rib sidewalls.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation on heat transfer performance of matrix cooling channels for turbine trailing edges

Qiao

Wang

Yan

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part A:

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The paper investigated numerically the heat transfer and pressure loss characteristics of the converging matrix cooling channels for turbine trailing edges with response surface method. The three selected design factors are scale factor ( SF), rib inclination angle ( α) and channel wedge angle ( β). The discussed range for the design factors, SF, α and β, are 2.5–10; 30°–60° and 1.5°–2.5°. And the investigated Reynolds number range is from 15,000 to 40,000. The turbulence model selected was SST k- ω model. It is newly found that the heat transfer and pressure loss characteristics of the converging matrix cooling channels depend heavily on the scaling effect. The matrix cooling channels with larger scale factor generally present higher heat transfer enhancement, higher pressure loss and lower overall thermal performance. In addition, the converging matrix cooling channels with smaller rib inclination angle and larger channel wedge angle present higher heat transfer enhancement and larger pressure loss. Among all the 13 cases, Case 9 with SF = 2.5, α = 45° and β = 1.5° has the highest averaged thermal performance factor under 6 Reynolds numbers.

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Effect of bleed hole on internal flow and heat transfer in matrix cooling channel

Cited by 18 publications

References 28 publications

Spatial effect of a vertical multi-faceted rib on thermal performance and flow characteristics in a square channel

Spatial effect of a vertical multi-faceted rib on thermal performance and flow characteristics in a square channel

Cooling Characteristic of a Wall Jet for Suppressing Crossflow Effect under Conjugate Heat Transfer Condition

Numerical investigation on heat transfer performance of matrix cooling channels for turbine trailing edges

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