Effect of Turbine Blade Tip Cooling Configuration on Tip Leakage Flow and Heat Transfer

Date

2019-06-21

Author

Sakaoğlu, Sergen
Kahveci, Harika Senem

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

193
views

0
downloads

The pressure difference between suction and pressure sides of a turbine blade leads to the so-called phenomenon, the tip leakage flow, which most adversely affects the first-stage high-pressure (HP) turbine blade tip aerodynamics. In modern gas turbines, HP turbine blade tips are also exposed to extreme thermal conditions requiring the use of tip cooling. If the coolant jet directed into the blade tip gap cannot counter the leakage flow, it will simply add up to the pressure losses due to this leakage flow. Therefore, it is necessary to handle the design of tip cooling in such a way that the compromise between the aerodynamic loss and the gain in the tip cooling effectiveness is optimized. In this paper, the effect of tip cooling configuration on the turbine blade tip is investigated numerically both from the aerodynamics and thermal aspects in order to determine the optimum tip cooling configuration. The studies are carried out using the tip cross-section of General Electric E3 (Energy Efficient Engine) HP turbine first-stage blade for two different tip geometries, squealer tip and flat tip, where the number, location, and diameter of the cooling holes are varied. The study presents a discussion on the overall loss coefficient, the total pressure loss across the tip clearance, and the variation of heat transfer on the blade tip. The aerodynamic and heat transfer results are compared with the experimental data from literature. It is observed that increasing the coolant mass flow rate by using more holes or by increasing the hole diameter results in a decrease in the area-averaged Nusselt number on the tip floor, as expected. The findings show that both aerodynamic and thermal response of the squealer tips to the implementation of cooling holes is superior to their flat counterparts. Among the studied configurations, the squealer tip with larger number of cooling holes located towards the pressure side is highlighted as the configuration having the best cooling performance.

Subject Keywords

Squealer Tip

URI

https://hdl.handle.net/11511/39016

DOI

https://doi.org/10.1115/gt2019-90130

Collections

Department of Aerospace Engineering, Conference / Seminar

Suggestions

OpenMETU
Core

Effect of Turbine Blade Tip Cooling Configuration on Tip Leakage Flow and Heat Transfer Sakaoglu, Sergen; Kahveci, Harika Senem (ASME International, 2020-02-01) The pressure difference between suction and pressure sides of a turbine blade leads to tip leakage flow, which adversely affects the first-stage high-pressure (HP) turbine blade tip aerodynamics. In modern gas turbines, HP turbine blade tips are exposed to extreme thermal conditions requiring cooling. If the coolant jet directed into the blade tip gap cannot counter the leakage flow, it will simply add up to the pressure losses due to leakage. Therefore, the compromise between the aerodynamic loss and the g...
EFFECT OF TURBINE BLADE TIP COOLING CONFIGURATION ON TIP LEAKAGE FLOW AND HEAT TRANSFER Kahveci, Harika Senem; Sakaoğlu, Sergen (2019-06-17) The pressure difference between suction and pressure sides of a turbine blade leads to the so-called phenomenon, the tip leakage flow, which most adversely affects the first-stage high- pressure (HP) turbine blade tip aerodynamics. In modern gas turbines, HP turbine blade tips are also exposed to extreme thermal conditions requiring the use of tip cooling. If the coolant jet directed into the blade tip gap cannot counter the leakage flow, it will simply add up to the pressure losses due to this leak...
Effects of camberwise varying tip injection on loss and wake characteristics of a low pressure turbine blade Mercan, Bayram; Dogan, Eda; Ostovan, Yashar; Uzol, Oğuz (2015-08-01) This paper presents the results of an experimental study that investigates the effects of camberwise varying tip injection on the total pressure loss and wake flow characteristics downstream of a row of Low Pressure Turbine (LPT) blades. This injection technique involves spanwise jets at the tip that are issued from a series of holes distributed along the camber line. The injection from each hole is individually and separately controlled using a computer driven solenoid valve and therefore the flow injectio...
Effects of tip injection on the performance and near wake characteristics of a model wind turbine rotor Abdulrahim, Anas; Anik, Ezgi; Ostovan, Yashar; Uzol, Oğuz (2016-04-01) This paper presents an investigation of the effects of tip injection on the performance and near wake characteristics of a model wind turbine rotor. Experiments are conducted by placing a three-bladed horizontal axis wind turbine rotor at the exit of an open-jet wind tunnel. The rotor blades are non linearly twisted and tapered with NREL 5826 airfoil profile. The nacelle, hub and the blades are specifically designed to allow pressurized air to pass through and get injected from the blade tips while the roto...
Effect of cavity depth on thermal performance of a cooled blade tip under rotation Sakaoglu, Sergen; Kahveci, Harika Senem (2019-11-01) In this paper, the effect of cavity geometry of a squealer blade tip on its thermal performance is investigated. Numerical analyses were performed for three depth-to-width ratios for a cooled squealer tip. Also investigated is the effect of cooling introduction into the flow tip and the effect of rotation via the comparison of stationary and rotational domains where the latter was simulated by rotating the blade. The rotational speed and boundary conditions used in the numerical study are chosen to represen...

Citation Formats

S. Sakaoğlu and H. S. Kahveci, “Effect of Turbine Blade Tip Cooling Configuration on Tip Leakage Flow and Heat Transfer,” 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/39016.