Effects of Tip Gap Size on the Aerodynamic Performance of a Cavity-Winglet Tip in a Turbine Cascade

Zhong, Fangpan; Zhou, Chao

doi:10.1115/1.4036677

Cited by 22 publications

(8 citation statements)

References 21 publications

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“…The profile of blade was redesigned from a typical highly-load high-pressure turbine blade. Many basic studies and experiments have been conducted on this kind of blade (Zhong and Zhou [17], Zhou and Zhou [18]).…”

Section: Methodsmentioning

confidence: 99%

Aero-thermal Performance of Coolant Released from Suction Surface in a High-Pressure Turbine Cascade

Liu¹,

Zhou²,

Zhou³

2019

Proceedings of Global Power &Amp; Propulsion Society

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Controlling the tip leakage flow is crucial for improving the aerodynamic and thermal performance of unshrouded highpressure turbines. The advantages of a single cooling hole to release coolant from suction surface were sought by numerical method in the cases of flat tip blade. Compared with no coolant case, the coolant cases exhibited significant differences on the intensity and evolution of tip leakage vortex and corresponding aero-thermal performance of turbine depending on locations to release coolant and blowing ratios of coolant. The impact of five axial locations to release coolant, namely 10%, 20%, 30%, 40%, and 50% axial chord of blade respectively, was studied. And the impact of three blowing ratios of coolant, namely 0.7, 1.4, and 2.1, was investigated. Within the scope of the current study, the best aerodynamic effect was achieved when the coolant was released before 30% axial chord of blade. The aerodynamic effect became worse when the coolant was released after that place. This phenomenon implied that it was a better strategy to release coolant at the initial period of evolution of tip leakage vortex. With regard to the cases with coolant released at 20% axial chord of blade, the mixed-out loss caused by tip leakage vortex reduced with the increasing of blowing ratio from 0.7 to 2.1. Last but not least, the thermal performance of suction surface of blade was improved with the increasing of blowing ratio.

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Section: Methodsmentioning

confidence: 99%

Aero-thermal Performance of Coolant Released from Suction Surface in a High-Pressure Turbine Cascade

Liu¹,

Zhou²,

Zhou³

2019

Proceedings of Global Power &Amp; Propulsion Society

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“…Among rotor tip designs: tip winglets, tip ribs and casing configuration are considered to be the best design to reduce tip thermal load. Zhong et al 17 constructed winglet cavity tip structure using numerical method and studied tip gap size effect. Yan et al 18 added winglets on both sides of tip and compared their effects on tip heat transfer.…”

Section: Introductionmentioning

confidence: 99%

Effect of casing purge flow on heat transfer and cooling performance of blade squealer tip for a gas turbine stage

Jiang

2021

Proceedings of the Institution of Mechanical Engineers, Part A:

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The first stage of GE-E3 turbine is employed to investigate effect of casing purge flow upstream rotor blade tip. Three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations and standard k-ω model are solved to obtain tip heat transfer simulations. The results reveal that: heat transfer coefficient of blade tip surface can be significantly reduced when casing purge flow is set. Tip averaged heat transfer coefficient of cases with and without swirly velocity casing purge flow decrease 3.5% and 3.4% compared with the case without casing purge flow. Compared with case which blowing ratio equals to 0.5, it can be found that averaged tip heat transfer coefficient of cases which blowing ratio equals to 1.0 and 1.5 decrease 2.3% and 1.8%, respectively. Setting blowing ratio as 1.0 can best cool tip surface without wasting cold air resources. Increasing rotating speed can induce cold air entering tip trailing region and improve local cooling effect. Flow structure inside the tip clearance are also revealed and discussed.

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“…The experimental measurement by Yaras and Sjolander 7 pointed out that the winglet tip design would reduce 10% of the tip leakage loss. Zhong et al 8 studied the aerodynamic performance of the suction-side winglet structure with different tip clearance sizes experimentally and numerically. The results showed that the suction-side rim structure effectively reduced the leakage flow intensity when the gap size was small.…”

Section: Introductionmentioning

confidence: 99%

Effects of the novel rib layouts on the tip leakage flow pattern and heat transfer performance of turbine blade

Jiang

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part G:

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The steady simulation with flow field and heat transfer performance for different rib layouts is investigated. By referring the GE-E3 turbine blade tip (Case 1) profile as a prototype model, four kinds of rib layouts of full rib structure (Case 2), half rib structure connected with suction side (Case 3), half rib structure connected with pressure side (Case 4), and half rib structure in the rear squealer cavity (Case 5) was designed. The availability of k-ω turbulence model was validated through comparison of heat transfer coefficient distribution with the experimental data. The area-averaged heat transfer coefficients of Case 5 decreases up to 11.3%, 3.1%, 11.3%, and 2.8% in comparison to Cases 1, 2, 3, and 4. The total pressure coefficient of Case 5 reduces by 1.4%, 2.7%, and 4.0% compared to Cases 1, 2, and 3. The results reveal that, among the five novel rib layout cases, Case 5 obtains the optimal comprehensive performance under the performance of considering tip heat transfer and cascade loss. Further investigation on the influence of Cases 1 and 5 at different rotational speeds on the flow field and heat transfer characteristics of the tip clearance is also illustrated and discussed.

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Effects of Tip Gap Size on the Aerodynamic Performance of a Cavity-Winglet Tip in a Turbine Cascade

Cited by 22 publications

References 21 publications

Aero-thermal Performance of Coolant Released from Suction Surface in a High-Pressure Turbine Cascade

Aero-thermal Performance of Coolant Released from Suction Surface in a High-Pressure Turbine Cascade

Effect of casing purge flow on heat transfer and cooling performance of blade squealer tip for a gas turbine stage

Effects of the novel rib layouts on the tip leakage flow pattern and heat transfer performance of turbine blade

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