The Basics of Powder Lubrication in High-Temperature Powder-Lubricated Dampers

1993 ◽  
Vol 115 (2) ◽  
pp. 372-382 ◽  
Author(s):  
H. Heshmat ◽  
J. F. Walton
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Basic Mechanism ◽  
Test Facility ◽  
Experimental Program ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Powder Lubrication ◽  
Basic Features ◽  
Selection Of

The objective of this investigation is to develop a novel powder-lubricated rotor bearing system damper concept for use in high-temperature, high-speed rotating machinery such as advanced aircraft gas turbine engines. The approach discussed herein consists of replacing a conventional oil lubrication or frictional damper system with a powder lubrication system that uses the process particulates or externally fed powder lubricant. Unlike previous work in this field, this approach is based on the postulate of the quasi-hydrodynamic nature of powder lubrication. This postulate is deduced from past observation and present verification that there are a number of basic features of powder flow in narrow interfaces that have the characteristic behavior of fluid film lubrication. In addition to corroborating the basic mechanism of powder lubrication, the conceptual and experimental work performed in this program provides guidelines for selection of the proper geometries, materials, and powders suitable for this tribological process. The present investigation describes the fundamentals of quasi-hydrodynamic powder lubrication and defines the rationale underlying the design of the test facility. The performance and the results of the experimental program present conclusions reached regarding design requirements as well as the formulation of a proper model of quasi-hydrodynamic powder lubrication.

scholarly journals The Basics of Powder Lubrication in High-Temperature Powder-Lubricated Dampers

1991 ◽  
Author(s):  
Hooshang Heshmat ◽  
James F. Walton
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Basic Mechanism ◽  
Test Facility ◽  
Experimental Program ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Powder Lubrication ◽  
Basic Features ◽  
Selection Of

The objective of this investigation is to develop a novel powder-lubricated rotor bearing system damper concept for use in high-temperature, high-speed rotating machinery such as advanced aircraft gas turbine engines. The approach discussed herein consists of replacing a conventional oil lubrication or frictional damper system with a powder lubrication system that uses the process particulates or externally-fed powder lubricant. Unlike previous work in this field, this approach is based on the postulate of the quasi-hydrodynamic nature of powder lubrication. This postulate is deduced from past observation and present verification that there are a number of basic features of powder flow in narrow interfaces that have the characteristic behavior of fluid film lubrication. In addition to corroborating the basic mechanism of powder lubrication, the conceptual and experimental work performed in this program provides guidelines for selection of the proper geometries, materials and powders suitable for this tribological process. The present investigation describes the fundamentals of quasi-hydrodynamic powder lubrication and defines the rationale underlying the design of the test facility. The performance and the results of the experimental program present conclusions reached regarding design requirements as well as the formulation of a proper model of quasi-hydrodynamic powder lubrication.

Marine Operation of Gas Turbine Engines and Waterjet Pumps for Small Passenger Vessels

1979 ◽  
Author(s):  
S. M. Kowleski ◽  
C. D. Harrington
Keyword(s):  
Gas Turbine ◽  
San Francisco ◽  
High Speed ◽  
San Francisco Bay ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Golden Gate ◽  
Operational Problem ◽  
Golden Gate Bridge ◽  
Selection Of

This paper describes the planning, developmental, equipment selection and operational problem phases of the high-speed ferry system presently being operated on San Francisco Bay by the Golden Gate Bridge, Highway and Transportation District. The reasons for the selection of the vessel propulsion package consisting of gas turbine engines and waterjet pumps are discussed in some detail. Most importantly, the paper covers the problems experienced to date with this equipment in continuous marine operation.

scholarly journals Leakage and Power Loss Test Results for Competing Turbine Engine Seals

2004 ◽  
Author(s):  
Margaret P. Proctor ◽  
Irebert R. Delgado
Keyword(s):  
High Temperature ◽  
Power Loss ◽  
High Speed ◽  
Operating Conditions ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Test Results ◽  
Test Rig ◽  
Labyrinth Seals ◽  
Turbine Engine

Advanced brush and finger seal technologies offer reduced leakage rates over conventional labyrinth seals used in gas turbine engines. To address engine manufactures’ concerns about the heat generation and power loss from these contacting seals, brush, finger, and labyrinth seals were tested in the NASA High Speed, High Temperature Turbine Seal Test Rig. Leakage and power loss test results are compared for these competing seals for operating conditions up to 922 K (1200 °F) inlet air temperature, 517 KPa (75 psid) across the seal, and surface velocities up to 366 m/s (1200 ft/s).

A Critical Review of Physical Models in High Temperature Multiphase Fluid Dynamics: Turbulent Transport and Particle-Wall Interactions

2021 ◽  
Author(s):  
Nishan Jain ◽  
Alexandra Le Moine ◽  
Geoffroy Chaussonnet ◽  
Alison Flatau ◽  
Luis Bravo ◽  
...  
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
High Speed ◽  
Multiphase Flows ◽  
Volcanic Ash ◽  
Physical Models ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Conceptual Foundation ◽  
Wall Interactions

Abstract This review article examines the last decade of studies investigating solid, molten and liquid particle interactions with one another and with walls in heterogeneous multiphase flows. Such flows are experienced in state-of-the-art and future-concept gas turbine engines, where particles from the environment, including volcanic ash, runway debris, dust clouds, and sand, are transported by a fluid carrier phase and undergo high-speed collisions with high-temperature engine components. Sand or volcanic ash ingestion in gas turbine engines is known to lead to power-loss and/or complete engine failure. The particle-wall interactions that occur in high temperature sections of an engine involve physics and intrinsic conditions that are sufficiently complex that they result in highly disparate and transient outcomes. These particles, which often times are made up of glassy constituents called CMAS (calcium-magnesium-alumino-silicate), are susceptible to phase change at combustor temperatures (1650?), and can deposit on surfaces, undergo elastic and plastic deformation, rebound, and undergo breakup. Considerable research has been put into developing empirical and physics-based models and numerical strategies to address phase interactions. This article provides a detailed account of the conceptual foundation of physics-based models employed to understand the behavior of particle-wall interaction, the evolution of numerical methods utilized for modeling these interactions, and challenges associated with improving models of particle-particle and particle-wall interactions needed to better characterize multiphase flows. It also includes description of a testbed for acquiring canonical data for model validation studies.

scholarly journals High Temperature Erosion Study of Metals Used in Turbomachinery

1984 ◽  
Author(s):  
W. Tabakoff ◽  
T. Wakeman
Keyword(s):  
High Temperature ◽  
Erosion Rate ◽  
Complex Problem ◽  
Test Facility ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Particulate Flows ◽  
Severe Erosion ◽  
Thermodynamic Conditions ◽  
High Temperature Erosion

Gas turbine engines operating in dusty environments are exposed to severe erosion, especially the compressor and the turbine components. Predicting erosion in rotating machinery is a very complex problem. In order to provide the basis for alloy selection in future turbines using pulverized coal, an investigation is undertaken to obtain a basic understanding of the mechanisms of erosion at high temperatures. For this purpose, a test facility has been designed to simulate the aerodynamic and thermodynamic conditions in the turbine. The effects of high temperature on the erosion rate for different alloys are experimentally determined and the results obtained are presented in this paper. The findings are very important in predicting erosion rate for future turbomachinery exposed to particulate flows.

HAYNES ALLOY 75

Alloy Digest ◽  
1999 ◽  
Vol 48 (7) ◽  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Heat Treating ◽  
Turbine Engines ◽  
Chromium Alloy ◽  
Gas Turbine Engines ◽  
Typical Application ◽  
Good Oxidation Resistance ◽  
Temperature Performance ◽  
Haynes Alloy

Abstract Haynes alloy 75 is an 80 nickel-20 chromium alloy with both good oxidation resistance and good mechanical properties at high temperatures. It is amenable to all forms of fabrication and welding. A typical application for sheet metal is fabrications in gas turbine engines. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming and heat treating. Filing Code: Ni-557. Producer or source: Haynes International Inc.

Renovation features of powder high-speed steels broaches with plazma hardening

2021 ◽  
pp. 82-85
Author(s):  
A.S. Politov ◽  
R.R. Latypov
Keyword(s):  
Gas Turbine ◽  
Comparative Studies ◽  
High Speed ◽  
Atmospheric Plasma ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Cold Atmospheric Plasma ◽  
Plasma Hardening

The comparative studies results of the durability of cutting properties of new and restored by regrinding and repeated plasma hardening with the application of multi-layer Si—O—C—N nanocoating system (PECVD by cold atmospheric plasma) powder high — speed steels broaches teeth for the processing of hard-to-process materials profilecomposite gas-turbine engines components are presented.

scholarly journals HEAT AND EROSION-RESISTANT NANOSTRUCTURED COATINGS FOR GAS TURBINE ENGINES

Aviation ◽  
2013 ◽  
Vol 17 (4) ◽  
pp. 137-144 ◽  
Author(s):  
Aleksandrs Urbahs ◽  
Konstantins Savkovs ◽  
Margarita Urbaha ◽  
Kristine Carjova
Keyword(s):  
Gas Turbine ◽  
Oxidation Process ◽  
Sample Surface ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Functional Coatings ◽  
Temperature Oxidation ◽  
Plasma Sputtering ◽  
Ion Plasma ◽  
Basic Features

This work analyses the characteristics of functional coatings obtained by vacuum ion-plasma sputtering. These coatings have three-layer multiphase structure created as a result of condensing aluminium and titanium according to a certain programme. The article presents the results of investigation into the heat-resistance of ion-plasma coatings based on Ti-Al-N for titanium alloy parts of gas turbine engines. Analysis of the oxidation process between a sample surface and coatings within the range of 500–825 °C was carried out. The basic features of the process of coating destruction under high-temperature oxidation conditions were determined by means of scanning electron microscopy. The results of the tests made it possible to state that the coatings developed are able to operate at temperatures of 600–750 °C.

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