Augmented heat transfer in a pin fin channel with short or long ejection holes

Kumaran, T.; Han, Je-Chin; Lau, S. C.

doi:10.1016/0017-9310(91)90101-j

Cited by 42 publications

(9 citation statements)

References 7 publications

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“…Lau et al [3] reported that side-wall ejection reduced the overall heat transfer when they evaluated heat-transfer coefficient (HTC) in pin-fin arrayed cooling channels with and without lateral ejections. Kumaran et al [4] compared HTC in three channel configurations: without, with short, and with long lateral ejection holes. In accordance with the observation of Lau et al [3], they found that the ejection holes reduced the downstream HTC considerably.…”

Section: Lateral Ejection Effect In Non-rotating Channelsmentioning

confidence: 99%

Heat transfer in a rotating smooth wedge-shaped channel with lateral fluid extraction

Tao

Qiu

Deng

2015

Applied Thermal Engineering

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Section: Lateral Ejection Effect In Non-rotating Channelsmentioning

confidence: 99%

Heat transfer in a rotating smooth wedge-shaped channel with lateral fluid extraction

Tao

Qiu

Deng

2015

Applied Thermal Engineering

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“…They concluded that the heat transfer effects of jet impingement on rib-roughened surfaces can be considerably improved by proper positioning on the jets with respect to the ribs. Kumaran et al [16] reported on augmented heat transfer in a pin fin channel with short or long ejection holes. Taslim et al [6][7][8][9][10][11] reported the results of a series of inves tigations on internal impingement on the leading-edge cavity walls.…”

Section: Introductionmentioning

confidence: 99%

Experimental/Numerical Investigation on the Effects of Trailing-Edge Cooling Hole Blockage on Heat Transfer in a Trailing-Edge Cooling Channel

Taslim

Huang

2014

Journal of Engineering for Gas Turbines and Power

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E x p e rim e n ta l/N u m e ric a l In v e s tig a tio n on th e Effects of T ra ilin g -E d g e C o o lin g H o le B lo ckag e on H e a t T ra n s fe r in a T ra ilin g -E d g e C o o lin g C h an n elHot and harsh environments, sometimes experienced by gas turbine airfoils, can create undesirable effects such as clogging of the cooling holes. Clogging of the cooling holes along the trailing edge of an airfoil on the tip side and its effects on the heat transfer coefficients in the cooling cavity around the clogged holes is the main focus of this inves tigation. Local and average heat transfer coefficients were measured in a test section sim ulating a rib-roughened trailing edge cooling cavity of a turbine airfoil. The rig was made up of two adjacent channels, each with a trapezoidal cross sectional area. The first channel supplied the cooling air to the trailing-edge channel through a row of racetrack shaped slots on the partition wall between the two channels. Eleven crossover jets, issued from these slots entered the trailing-edge channel, impinged on eleven radial ribs and exited from a second row of race-track shaped slots on the opposite wall that simulated the cooling holes along the trailing edge of the airfoil. Tests were run for the baseline case with all exit holes open and for cases in which 2, 3, and 4 exit holes on the airfoil tip side were clogged. All tests were run for two crossover jet angles. The first set of tests were run for zero angle between the jet axis and the trailing-edge channel centerline. The jets were then tilted towards the ribs by five degrees. Results of the two set of tests for a range of jet Reynolds number from 10,000 to 35,000 were compared. The numerical mod els contained the entire trailing-edge and supply channels with all slots and ribs to simu late exactly the tested geometries. They were meshed with all-hexa structured mesh of high near-wall concentration. A pressure-correction based, multiblock, multigrid, unstructured!adaptive commercial software was used in this investigation. The realizable k-e turbulence model in combination with enhanced wall treatment approach for the near wall regions were used for turbulence closure. Boundary conditions identical to those of the experiments were applied and several turbulence model results were compared. The numerical analyses also provided the share of each crossover and each exit hole from the total flow for different geometries. The major conclusions of this study were: (a) clogging o f the exit holes near the airfoil tip alters the distribution of the coolant mass flow rate through the crossover holes and changes the flow structure. Depending on the number of clogged exit holes (from 3 to 6, out of 12), the tip-end crossover hole experienced from 35% to 49% reductions in its mass flow rate while the root-end crossover hole, under the same conditions, experienced an increase o f the same magnitude in its mass flow rate, (b) Up to 64% reduction in heat transfer coefficients on the tip-end surface areas around the clogged h...

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“…However, results show that short pin fin arrays produce higher heat transfer than plain channels without pin fins as well as an increased pressure loss [1][2][3][4]. The increase in energy cost per unit with energy consumption has required more effective use of energy.…”

Section: Introductionmentioning

confidence: 99%

Entropy generation of staggered short pin fin arrays

Liu

Jiang

2011

2011 International Conference on Remote Sensing, Environment and Transportation Engineering

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Staggered short pin fins are usually used to increase the heat transfer in modern gas turbine blade mainly due to its function of increasing the level of turbulence in the cooling flow, which leads to both higher heat transfer and pressure drop. In order to decrease the energy loss of the cooling flow, an entropy generation analysis was carried out for a pin fin array. The entropy generation model was established based on the second-law analysis. Three types of pins with stepped diameter were studied. The distribution of the entropy generation due to heat transfer and fluid friction irreversibility respectively was analyzed. The entropy generation number component due to heat transfer decreased as Re d increased, while the component due to fluid friction increased with the increase of Re d . The entropy generation number took its minimum value when the two components met and the corresponding Reynolds number was optimal. Thermal diffusion of the fluid strongly influenced the entropy generation at small Reynolds number, while the effect of fluid friction on entropy generation became dominant at large Reynolds number. Keywords-heat transfer; pin fin array; entropy generation I.978-1-4244-9171-1/11/$26.00 ©2011 IEEE

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Augmented heat transfer in a pin fin channel with short or long ejection holes

Cited by 42 publications

References 7 publications

Heat transfer in a rotating smooth wedge-shaped channel with lateral fluid extraction

Heat transfer in a rotating smooth wedge-shaped channel with lateral fluid extraction

Experimental/Numerical Investigation on the Effects of Trailing-Edge Cooling Hole Blockage on Heat Transfer in a Trailing-Edge Cooling Channel

Entropy generation of staggered short pin fin arrays

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