Flow and Heat Transfer Predictions for a Flat-Tip Turbine Blade

Yang, Haiyuan; Acharya, Sumanta; Ekkad, Srinath V.; Prakash, Chander; Bunker, Ronald S.

doi:10.1115/gt2002-30190

Cited by 41 publications

(23 citation statements)

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“…This feature was previously noted experimentally by Sjolander and Amrud 18) and numerically by Yang et al 14) On the tip surface, there is a high pressure ratio (low static pressure) region, indicating a high velocity flow. This region covers about one third of the tip area.…”

Section: Flat-tip Casesupporting

confidence: 58%

“…Figure 3 shows the pressure distribution along the blade surface in the case of the flat tip with TCS ratio of 1.5%, along with the numerical results of Yang et al 14) for validation. The vertical axis is the pressure ratio, p to =p s , where p s is the static pressure on the wall.…”

Section: Methodsmentioning

confidence: 99%

“…Calculation was performed for a three times scaled-up model in the same way as Yang et al 14) This scaled-up model has an axial chord of 86.1 mm (Cx ¼ 86:1), a span of 122 mm (h ¼ 122), and an aspect ratio of 1.4 (AR ¼ 1:4). The blade model is 2D with the same profile in the span direction.…”

Section: Model Inmentioning

confidence: 99%

“…Ameri and Steinthorsson to predict the heat transfer rate on the tip of shrouded/ unshrouded turbine rotors of the SSME (Space Shuttle Main Engine). Yang et al 14) applied three different turbulence models (standard high Re k-", RNG k-", and Reynolds stress model) to heat transfer prediction, and analyzed the heat transfer of the first-stage high-pressure turbine rotor blade of the General Electric-Energy Efficient Engine (GE-E 3 ). 15) This paper proposes a new blade tip shape called triple squealer.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Control of Leakage Flow by Triple Squealer Configuration in Axial Flow Turbine

El-Ghandour

Ibrahim

Mori

et al. 2010

Trans. Japan Soc. Aero. S Sci.

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A new turbine blade tip shape called triple squealer is proposed. This shape is based on the conventional double squealer, and the cavity on the tip surface is divided into two parts by using a third squealer along the blade camber line. The effect of the ratio of groove depth to span (GDS ratio) was investigated. The flat-tip case (baseline case) and doublesquealer case were calculated for comparison. In-house, unstructured, 3D, Navier-Stokes, finite volume, multiblock code with DES (Detached Eddy Simulation) as turbulence model was used to calculate the flow field around the tip. The computational results show that the reduction in the mass flow rate of the leakage flow for the triple squealer is 15.69% compared to the flat-tip case.

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Section: Flat-tip Casesupporting

confidence: 58%

Section: Methodsmentioning

confidence: 99%

Section: Model Inmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Control of Leakage Flow by Triple Squealer Configuration in Axial Flow Turbine

El-Ghandour

Ibrahim

Mori

et al. 2010

Trans. Japan Soc. Aero. S Sci.

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show abstract

“…Leschziner et al [28] gave a detailed review of turbulence models in aeronautics. There are various turbulence models employed in the existing literatures, such as the standard k-ω model by Yang et al [18], the SST k-ω model by Krishnababu et al [20] and the RNG k-ε model by Yang et al [29]. To validate the numerical strategy including the turbulence model, an To reduce the heat impinging of the leakage flow on the tip, the new rotor of the squealer tip with a grooved structure has been widely employed in the blades instead of the traditional flat tip.…”

Section: Introductionmentioning

confidence: 99%

Effect of Relative Movement between the Shroud and Blade on Tip Leakage Flow Characteristics

Wang

et al. 2017

Energies

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An experimental and numerical investigation into the tip leakage flow of a turbine rotor is carried out using a particle image velocimetry (PIV) system and the commercial software ANSYS CFX 14.0. The specimen used in this work is a typical GE-E 3 model with a new squealer tip design. The experimental data are used to create a turbulence model and numerical strategy. Through the validated turbulence model and numerical strategy, simulations are carried out to compare the characteristics of the tip leakage flow in three cases: (1) the blade is rotating, but the shroud is stationary, which is the real status of turbine rotor operation; (2) the blade is stationary, but the shroud moves, to simulate their relative movement; (3) the blade is stationary, and the shroud is also stationary, this is a simplified case, but has been widely used in the experiments on rotor tip leakage flow. Detailed analysis of the flow phenomena shows that the second case is a reasonable alternative approach to simulate the real state. However, the flow patterns in the third case exhibit some evident differences from the real status. These differences are caused by the inaccurate viscous force arising from the stationary blade and shroud. In this work, a modification method for the experiments conducted in the third case is firstly proposed, which is realized through adding an imaginary roughness at the shroud wall to be close to the real viscous effect, and to thereby reduce the deviation of the experiment from the real case. According to the results calculated by ANSYS CFX, the flow structure in the modification case is very close to the real status. Besides, this modification case is an easy and cheap way to simulate the real tip leakage flow.

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Aerothermal characteristics of transonic over-tip leakage flow for different tip geometries with cooling injection

Tang

Liu

et al. 2019

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In turbomachinery, the effect of cooling injection on the over-tip leakage (OTL) flow has been the focus. In the present work, the flow and heat transfer on the blade tip surfaces of two typical different tip structures including a flat tip and a squealer tip are investigated. The grid independence verification and turbulence model validation (including Shear Stress Transport k-ω model and Spalart-Allmaras model) are conducted. Numerical results are compared with the existing experimental results. It is found that there exists the shock wave near the corner of the pressure side, and a striped high-pressure coefficient region appears on the tip surface near the pressure side. The cooling injection could alter the range of high striped pressure coefficient region. The tip leakage vortex (TLV) was formed by the blending between the OTL flow and mainstream, causing a large aerodynamic penalty. In comparison, the flat tip shows a greater loss near the casing and the tip surface than the squealer tip. An interesting observation is that the coolant ejecting from the cooling jet hole bifurcates and then forms a counter-rotating vortex pair (CRVP) for both the flat tip and the squealer tip, which greatly changes the flow structures and heat transfer characteristics within the tip region. The branches of the CRVP cause the thermal stripes on the surfaces of blade tip and the suction side rim. The present results reveal the cooling injection has a strong effect on OTL flow and enlighten the design and optimization of blade tips.

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Flow and Heat Transfer Predictions for a Flat-Tip Turbine Blade

Cited by 41 publications

References 0 publications

Control of Leakage Flow by Triple Squealer Configuration in Axial Flow Turbine

Control of Leakage Flow by Triple Squealer Configuration in Axial Flow Turbine

Effect of Relative Movement between the Shroud and Blade on Tip Leakage Flow Characteristics

Aerothermal characteristics of transonic over-tip leakage flow for different tip geometries with cooling injection

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