702 Study on Flow Characteristics in Rotor Disk Rim Seal of a Gas Turbine with Uneven Velocity Profile of Hot Gas

The rotating components in the hot sections of land-based gas turbine are exposed to severe environment during several ten thousand hours at above 1100 oC operating temperature. The failure mechanism of the hot gas components would be accompanied by material degradation in the properties of high temperature and creep rupture strength. Many hot gas components in gas turbine are made of Ni-based superalloy because of their high temperature performance. In this work, we surveyed the time and temperature dependent degradation of Ni-based superalloy. We prepared the specimens from GTD111 that are exposed at 871 oC and 982 oC in 1,000 ~ 10,000 hours. We carried out the mechanical test and microstructural observation.

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Numerical Investigation of Improving Turbine Sealing Effectiveness Through Slot Width Modification of the Rim Seal

Volume 3A: Heat Transfer ◽

10.1115/gt2013-95570 ◽

2013 ◽

Cited By ~ 1

Author(s):

Jinghui Zhang ◽

Hongwei Ma

Keyword(s):

Radial Velocity ◽

Gas Turbine ◽

Flow Region ◽

Main Flow ◽

Slot Width ◽

Wake Region ◽

Reference Case ◽

Cooling Flow ◽

Hot Gas ◽

Root Region

The hot gas in the main annulus of a gas turbine can ingest into the rotor-stator cavities through the rim seal clearance as a result of the interaction of the rotor and the stator disks and the external flow in the hot gas annulus. To prevent the turbine root region from being heated up, this ingestion has to be avoided almost completely. This paper introduces a new idea to improve turbine sealing effectiveness through slot width modification of the rim seal. Unsteady numerical simulations are performed with two different rim seal geometries at the design condition with different cooling flow rates. Both of the rim seal geometries are simple axial seal configurations. One is uniform slot rim seal geometry and is taken as the reference case. The other is a new kind of rim seal geometry with slot width modification. The clearance is bigger in the main flow path and smaller in the stator wake region keeping the area of the two kinds of rim seal surfaces equivalent. The sealing air egress happens in the main path flow region and the ingestion happens in the stator wake region. Through comparing the results of the two kinds of rim seal geometries, it is found out that the contoured slot rim seal geometry can reduce the pressure in the cavity which leads to the decrease of the gas turbine loss. The inward radial velocity of the ingestion increases in the stator wake region and hence the axial seal gap has been reduced in this region. The time-averaged outward radial velocity decreases in the main flow region and becomes more uniform. Unsteady flow patterns in the rim seal region are compared for the two seal configurations. The sealing effectiveness is rapidly improved by using the contoured seal configuration. This work provides an idea to increase the sealing effectiveness and decrease the pressure in the cavity.

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Assessment of coal gasification/hot gas cleanup based advanced gas turbine systems: Greenfield assessment

10.2172/5492966 ◽

1991 ◽

Cited By ~ 1

Author(s):

Keyword(s):

Gas Turbine ◽

Coal Gasification ◽

Hot Gas

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Calculation of flow characteristics of liquid fuel supplied through pressure jet atomizers of small-sized gas turbine engines

VESTNIK of the Samara State Aerospace University ◽

10.18287/2541-7533-2021-20-2-19-35 ◽

2021 ◽

Vol 20 (2) ◽

pp. 19-35

Author(s):

N. I. Gurakov ◽

I. A. Zubrilin ◽

M. Hernandez Morales ◽

D. V. Yakushkin ◽

A. A. Didenko ◽

...

Keyword(s):

Gas Turbine ◽

Liquid Fuel ◽

Cone Angle ◽

Flow Characteristics ◽

Design Parameters ◽

Turbine Engines ◽

Gas Turbine Engines ◽

Spray Cone Angle ◽

Spray Cone ◽

Semi Empirical

The paper presents the results of studying the flow characteristics of liquid fuel in pressure jet atomizers of small-sized gas turbine engines with nozzle diameters of 0.4-0.6 mm for various operating and design parameters. The study was carried out using experimental measurements, semi-empirical correlations and CFD (computational fluid dynamics) methods. The Euler approach, the volume- of- fluid (VOF) method, was used to model multiphase flows in CFD simulations. Good agreement was obtained between experimental and predicted data on the fuel coefficient and the primary spray cone angle at the nozzle outlet. Besides, the assessment of the applicability of semi-empirical techniques for the nozzle configurations under consideration is given. In the future, the flow characteristics in question (the nozzle flow rate, the fuel film thickness, and the primary spray cone angle) can be used to determine the mean diameter of the droplets (SMD) required to fully determine the boundary conditions of fuel injection when modeling combustion processes in combustion chambers of small-sized gas turbine engines.

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