Unsteady Tip Leakage Flow Characteristics and Heat Transfer on Turbine Blade Tip and Casing

Rahman, M. Hamidur; Kim, Sung In; Hassan, Ibrahim; Ayoubi, Carole El

doi:10.1115/gt2010-22104

Cited by 6 publications

(4 citation statements)

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“…There were 40 time-step in a guide vane passing period and each step has 20 subiterations. As for the such selection, we have referenced the research work of Rahman et al (2010) 23 who illustrated several combinations of different time-step and sub-iteration for similar unsteady simulation. It was concluded that using 20 sub-iteration and 40 time-step in a guide vane passing period to conduct the unsteady simulation could provide gridindependent converged solutions.…”

Section: Methodsmentioning

confidence: 99%

“…Ameri et al 21,22 used three different defined sinusoidal functions to approximate the non-uniform inlet conditions of rotor passage to investigate blade unsteady heat transfer characteristics. Rahman et al 23 performed simulations on a single-stage turbine and compared transient, averaged, and steady results, showing HTC and leakage flow are highly time-independent. Phutthavong et al 24 carried out 3 D unsteady simulations on a certain turbine stage and explored the effect of rotational speed, tip clearance, etc.…”

Section: Introductionmentioning

confidence: 99%

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Aerothermal and aerodynamic performance of turbine blade squealer tip under the influence of guide vane passing wake

Zhang

Qiang

2020

Proceedings of the Institution of Mechanical Engineers, Part A:

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In this paper, the performance of the turbine blade squealer tip has been studied detailed aimed to highlight the impact of the upstream guide vane passing wake. The first stage of GE-E3 high-pressure turbine has been employed to perform the three-dimensional simulation and the computational domain has been scaled based on the domain scaling method. Boundary conditions are consistent with operating conditions of the annular cascade testing. Circumferential averaged and realistic non-uniform interface conditions have been used to obtain steady and unsteady characteristics respectively. The validation of the turbulent model and mesh independent test has been conducted detailed in previous work. Three squealer tips, including two widths and heights, have been designed and investigated to understand its influence. Results show that the aerothermal performance of the squealer tip is remarkably influenced by the upstream passing wake. Although steady and time-averaged results have a good agreement, the variation of instantaneous heat transfer coefficient (HTC) would be over 30%, especially on the Cavity Floor region. Changing the geometry of the squealer also has different impacts on both steady and unsteady performance. The unsteady aerodynamic has relatively small fluctuation within 10%, and the distribution of steady and time-averaged leakage flow as well as total pressure loss coefficient still have a satisfactory agreement.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Aerothermal and aerodynamic performance of turbine blade squealer tip under the influence of guide vane passing wake

Zhang

Qiang

2020

Proceedings of the Institution of Mechanical Engineers, Part A:

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“…10 and RB at t*=1/8, FB and RB at t*=3/8 in Fig. 11; low heat transfer rate near pressure side by SB, high heat transfer rate by LR, and heat transfer rate decreasing again by the secondary reversed leakage vortex (SRLV), a vortical mixing between the tip leakage flow and RR (Rahman et al 2010). The inlet flow angle (indicated by an arrow in Fig.…”

Section: Heat Transfer Rate Distribution Variationmentioning

confidence: 99%

“…In the earlier studies (Rahman et al, 2010(Rahman et al, , 2013Kim et al 2012), grid sensitivity and validations and steady analysis of tip leakage flow structures and heat transfer distributions have been investigated. Also, the effect of tip clearance heights and rotor speeds on tip leakage flow and heat transfer rate was systematically analyzed.…”

Section: Umentioning

confidence: 99%

Tip Leakage Flow and Heat Transfer on Turbine Stage Tip and Casing: Effect of Unsteady Stator–rotor Interactions

Rahman

Kim

Hassan

2014

Int. J. Comput. Methods

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Effect of turbine inlet temperature on rotor blade tip leakage flow and heat transfer

Kim

Rahman

Hassan

2012

International Journal of Numerical Methods for Heat &Amp; Fluid Flow

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PurposeOne of the most critical gas turbine engine components, the rotor blade tip and casing, is exposed to high thermal load. It becomes a significant design challenge to protect the turbine materials from this severe situation. The purpose of this paper is to study numerically the effect of turbine inlet temperature on the tip leakage flow structure and heat transfer.Design/methodology/approachIn this paper, the effect of turbine inlet temperature on the tip leakage flow structure and heat transfer has been studied numerically. Uniform low (LTIT: 444 K) and high (HTIT: 800 K) turbine inlet temperature, as well as non‐uniform inlet temperature have been considered.FindingsThe results showed the higher turbine inlet temperature yields the higher velocity and temperature variations in the leakage flow aerodynamics and heat transfer. For a given turbine geometry and on‐design operating conditions, the turbine power output can be increased by 1.33 times, when the turbine inlet temperature increases 1.80 times. Whereas the averaged heat fluxes on the casing and the blade tip become 2.71 and 2.82 times larger, respectively. Therefore, about 2.8 times larger cooling capacity is required to keep the same turbine material temperature. Furthermore, the maximum heat flux on the blade tip of high turbine inlet temperature case reaches up to 3.348 times larger than that of LTIT case. The effect of the interaction of stator and rotor on heat transfer features is also explored using unsteady simulations. The non‐uniform turbine inlet temperature enhances the heat flux fluctuation on the blade tip and casing.Originality/valueThe increase of turbine inlet temperature is usually proposed to achieve the higher turbine efficiency and the higher turbine power output. However, it has not been reported how much the heat transfer into the blade tip and casing increases with the increased turbine inlet temperature. This paper investigates the heat transfer distributions on the rotor blade tip and casing, associated with the tip leakage flow under high and low turbine inlet temperatures, as well as non‐uniform temperature distribution.

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Unsteady Tip Leakage Flow Characteristics and Heat Transfer on Turbine Blade Tip and Casing

Cited by 6 publications

References 0 publications

Aerothermal and aerodynamic performance of turbine blade squealer tip under the influence of guide vane passing wake

Aerothermal and aerodynamic performance of turbine blade squealer tip under the influence of guide vane passing wake

Tip Leakage Flow and Heat Transfer on Turbine Stage Tip and Casing: Effect of Unsteady Stator–rotor Interactions

Effect of turbine inlet temperature on rotor blade tip leakage flow and heat transfer

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