Wall thickness monitoring method for wax pattern of hollow turbine blade

The paper presents an integral core/shell fabrication of ceramic casting mould for hollow turbine blades by combining SL (Stereolithography) with gelcasting. This method could guarantee the positional accuracy between ceramic cores and shell, thus achieving the rapid fabrication of complex turbine blade castings. The paper focuses on the design of resin mould for gelcasting, the preparation of ceramic slurry, the pyrolysis of resin prototype and the sintering of ceramic green body. The feasibility and effectiveness of above mentioned method were verified through successful manufacturing of hollow turbine blades with double-walled structure.

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An Investigation on Aerodynamics Loss Mechanism of Squealer Tips of a High Pressure Turbine Blade Using URANS

Volume 2D: Turbomachinery ◽

10.1115/gt2016-57313 ◽

2016 ◽

Cited By ~ 4

Author(s):

Jin-sol Jung ◽

Okey Kwon ◽

Changmin Son

Keyword(s):

High Pressure ◽

Turbine Blade ◽

Wall Thickness ◽

Suction Side ◽

Leakage Flow ◽

Pressure Side ◽

Tip Leakage Flow ◽

High Pressure Turbine ◽

Loss Mechanism ◽

Tip Leakage

The flow leaking over the tip of a high pressure turbine blade generates significant aerodynamic losses as it mixes with the mainstream flow. This study investigates the effect of blade tip geometries on turbine performance with both steady RANS and unsteady URANS analyses. Five different squealer geometries for a high pressure turbine blade have been examined: squealer on pressure side, squealer on suction side, cavity squealer, cavity squealer with pressure side cutback, and cavity squealer with suction side cutback. With the case of the cavity squealer, three different squealer wall thickness are investigated for the wall thickness (w) of 1x, 2x and 4x of the tip gap (G). The unsteady flow analyses using CFX have been conducted to investigate unsteady characteristics of the tip leakage flow and its influence on turbine performances. Through the comparison between URANS analyses, detailed vortex and wake structures are identified and studied at different fidelities. It is found that the over tip leakage flow loss is affected by the tip suction side geometry rather than that of the pressure side geometry. The unsteady results have contributed to resolve the fundamentals of vortex structures and aerodynamic loss mechanisms in a high pressure turbine stage.

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On Improving Full-Coverage Effusion Cooling Efficiency by Varying Cooling Arrangements and Wall Thickness in Double Wall Cooling Application

Volume 5A: Heat Transfer ◽

10.1115/gt2018-77230 ◽

2018 ◽

Author(s):

Weihong Li ◽

Xunfeng Lu ◽

Xueying Li ◽

Jing Ren ◽

Hongde Jiang

Keyword(s):

Gas Turbine ◽

Turbine Blade ◽

Wall Thickness ◽

Film Cooling ◽

Density Ratio ◽

Cooling Efficiency ◽

Gas Turbine Blade ◽

Cooling Effectiveness ◽

Full Coverage ◽

Double Wall

Overall cooling effectiveness was determined for a full-coverage effusion cooled surface which simulated a portion of a double wall cooling gas turbine blade. The overall cooling effectiveness was measured with high thermal-conductivity artificial marble using infra-red thermography. The Biot number of artificial marble was matched to real gas turbine blade conditions. Blowing ratio ranged from 0.5 to 2.5 with the density ratio of DR = 1.5. A variation of cooling arrangements, including impingement-only, film cooling-only, film cooling with impingement and film cooling with impingement and pins, as well as forward/backward film injection, were employed to provide a systematic understanding on their contribution to improve cooling efficiency. Also investigated was the effect of reducing wall thickness. Local, laterally-averaged, and area-averaged overall cooling effectiveness were shown to illustrate the effects of cooling arrangements and wall thickness. Results showed that adding impingement and pins to film cooling, and decreasing wall thickness increase the cooling efficiency significantly. Also observed was that adopting backward injection for thin full-coverage effusion plate improves the cooling efficiency.

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The Impact of the Thickness of the Ceramic Shell Mould on the (γ + γ′) Eutectic in the IN713C Superalloy Airfoil Blade Casting

Archives of Metallurgy and Materials ◽

10.1515/amm-2017-0087 ◽

2017 ◽

Vol 62 (2) ◽

pp. 587-593 ◽

Cited By ~ 3

Author(s):

A. Szczotok ◽

J. Nawrocki ◽

J. Pietraszek

Keyword(s):

Wall Thickness ◽

Cross Sections ◽

Volume Fraction ◽

Suction Side ◽

Chemical Compositions ◽

Ceramic Shell ◽

Wax Pattern ◽

Shell Mould ◽

Blade Casting ◽

The Impact

AbstractIn the study the wall thickness of ceramic shell mould influence on (γ+γ′) eutectic in the IN713C nickel-based superalloy airfoil blade casting was described.Two castings formed as a blade from two wax pattern assemblies were analysed. In the experiment in one pattern the thick ceramic layer was obtained on pressure side and in another one on suction side of the airfoil blade. The microstructure of the cross-sections of the castings were observed on polished and etched metallographic specimens. The microstructure and phases chemical compositions of specimens was analyzed by using the scanning electron microscope Hitachi S-4200 equipped with EDS. It was established, that wall thickness of ceramic shell mould affect size, shape and volume fraction of (γ+γ′) eutectic islands in airfoil blade made from IN713C superalloy.The analysis was provided in accordance to the typical statistical methodology [1].

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