Leak detection in the lubrication system of an aircraft turbine engine

2011 ◽  
pp. 566-571
Author(s):  
L Rakoto ◽  
M Kinnaert ◽  
M Strengnart ◽  
N Raimarckers
Keyword(s):  
Leak Detection ◽  
Lubrication System ◽  
Turbine Engine

Investigation of Vapor-Phase Lubrication in a Gas Turbine Engine

1997 ◽  
Author(s):  
Kenneth W. Van Treuren ◽  
D. Neal Barlow ◽  
William H. Heiser ◽  
Matthew J. Wagner ◽  
Nelson H. Forster
Keyword(s):  
Gas Turbine ◽  
Vapor Phase ◽  
Gas Turbine Engine ◽  
Rolling Contact ◽  
Phosphate Ester ◽  
Lubrication System ◽  
Oil Lubrication ◽  
Vapor Phase Lubrication ◽  
Engine Operation ◽  
Turbine Engine

The liquid oil lubrication system of current aircraft jet engines accounts for approximately 10–15% of the total weight of the engine. It has long been a goal of the aircraft gas turbine industry to reduce this weight. Vapor-Phase Lubrication (VPL) is a promising technology to eliminate liquid oil lubrication. The current investigation resulted in the first gas turbine to operate in the absence of conventional liquid lubrication. A phosphate ester, commercially known as DURAD 620B, was chosen for the test. Extensive research at Wright Laboratory demonstrated that this lubricant could reliably lubricate railing element bearings in the gas turbine engine environment. The Allison T63 engine was selected as the test vehicle because of its small size and bearing configuration. Specifically, VPL was evaluated in the number eight bearing because it is located in a relatively hot environment, in line with the combustor discharge, and it can be isolated from the other bearings and the liquid lubrication system. The bearing was fully instrumented and its performance with standard oil lubrication was documented. Results of this baseline study were used to develop a thermodynamic model to predict the bearing temperature with VPL. The engine was then operated at a ground idle condition with VPL with the lubricant misted into the #8 bearing at 13 ml/hr. The bearing temperature stabilized at 283°C within 10 minutes. Engine operation was continued successfully for a total of one hour. No abnormal wear of the rolling contact surfaces was found when the bearing was later examined. Bearing temperatures after engine shutdown indicated the bearing had reached thermodynamic equilibrium with its surroundings during the test. After shutdown bearing temperatures steadily decreased without the soakback effect seen after shutdown in standard lubricated bearings. In contrast, the oil lubricated bearing ran at a considerably lower operating temperature (83°C) and was significantly heated by its surroundings after engine shutdown. In the baseline tests, the final bearing temperatures never reached that of the operating VPL system.

A Simple Thermal Model of Bearings With Transient Effects

2010 ◽  
Author(s):  
Karleine M. Justice ◽  
Ian Halliwell ◽  
Jeffrey S. Dalton
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Thermal Management ◽  
Heat Load ◽  
Transient Behavior ◽  
Gas Turbine Engine ◽  
System Level ◽  
Lubrication System ◽  
Transient Effects ◽  
Turbine Engine

In thermal management, system-level models provide an understanding of interactions between components and integration constraints — issues which are exacerbated by tighter coupling in both real life and simulation. A simple model of the steady-state thermal characteristics of the bearings in a two-spool turbofan engine has been described in previous work [1], where it was compared with a more comprehensive tribology-based simulation. Since failure is more likely to occur during transient rather than steady-state operating conditions, it is important that transient behavior is also studied. Therefore, development of models capable of capturing transient system-level performance in air vehicles is critical. In the current paper, the former simple model is used for the generation of a method to replicate the transient effects of heat loads within the lubrication system of a gas turbine engine. The simple engine model that defined the lubrication system is representative of a twin-spool, mid-size, high bypass ratio turbofan used in commercial transport. In order to demonstrate the range and versatility of the parametric heat load model, the model is now applied to the transient operation of a low-thrust unmanned aerial vehicle (UAV) engine, similar to that found on the Global Hawk. There are five separate bearings in the oil loop model and four separate oil sump locations. Contributions to the heat load calculations are heat transfer through the bearing housings and friction caused by station temperatures and shaft speeds, respectively. The lubrication system has been simplified by applying general assumptions for a proof-of-concept of the new transient parametric model. The fuel flow rate for the fuel-cooled oil cooler (FCOC) is set via the full authority digital electronic control (FADEC) in the transient engine model which is coupled to the parametric heat load model. Initially, it is assumed that total heat transfer from the bearings to the oil correspond to oil temperature changes of 150–250°F (83–139°C). The results show that successful modeling of the transient behavior on the thermal effects in the bearings of a gas turbine engine using the MATLAB/Simulink environment have been achieved. This is a valuable addition to the previous steady-state simulation, and the combined tools may be used as part of a more sophisticated thermal management system. Because it is so simple and scalable, the tool enables thermal management issues to be addressed in the preliminary design phase of a gas turbine engine development program.

Lube Oil and Bearing Thermal Management System

2009 ◽  
Author(s):  
Karleine M. Justice ◽  
Jeffrey S. Dalton ◽  
Ian Halliwell ◽  
Stephen Williamson
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Thermal Management ◽  
Gas Turbine Engine ◽  
System Level ◽  
Engine Oil ◽  
Management Systems ◽  
Lubrication System ◽  
Turbine Engine ◽  
Heat Loads

Recent improvements in technology have enabled the development of models capable of capturing performance interactions in the thermal management of air vehicle systems. Such system level models are required for better understanding of integration constraints and interactions, and are becoming increasingly important because of the need for tighter coupling between the components of thermal management systems. The study described here integrates current engine modeling capabilities with an improved, more comprehensive thermal management simulation. More specifically, the current effort evaluates the heat loads associated with the lubrication system of a gas turbine engine. The underlying engine model represents a mid-size, two-spool, subsonic transport engine. The architecture of the model is adaptable to other two-spool turbine engines and missions. Mobil Avrex S Turbo 256 engine oil is used as the lubrication medium. The model consists of five bearing heat loads. Within the engine flowpath, local temperatures and the appropriate rotational speeds are the only parameters pertinent to the heat load calculations. General assumptions have been made to simplify the representation of the lubrication system. Fuel properties into the heat exchanger are assumed. A gear box attached to the high-speed shaft operates both supply pump and scavenge pump and sends compressed air to the oil reservoir. Once the oil is distributed to the bearings, the scavenge pump collects and sends it through a filter and a fuel/oil heat exchanger before it is remixed with the contents of the reservoir. A MATLAB/Simulink modeling environment provides a general approach that may be applied to the thermal management of any engine. As a result of this approach, the new model serves as a starting point for a flexible architecture that can be modified as more detailed specifications or data are made available. In this paper, results from the simple model are compared to a more comprehensive tribology-based analysis. The results demonstrate its successful application to a typical mission, based on very limited data. In general, these results will allow system designers to conduct preliminary analyses and trade studies of gas turbine engine thermal management systems.

High Temperature Aircraft Turbine Engine Bearing and Lubrication System Development

2009 ◽  
pp. 409-409-26 ◽  
Author(s):  
DH Grant ◽  
HA Chin ◽  
C Klenke ◽  
AT Galbato ◽  
MA Ragen ◽  
...  
Keyword(s):  
High Temperature ◽  
System Development ◽  
Lubrication System ◽  
Turbine Engine ◽  
Engine Bearing

scholarly journals Determination of temperature mode of rotary bearings of gas turbine engine with air and fuel lubrication system

2020 ◽  
Vol 4 (2) ◽  
pp. 117-128
Author(s):  
V. N. Klimov ◽  
◽  
D. Ya. Dudev ◽  
V. Ya. Sigaylo ◽  
N. I. Klimov ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Lubrication System ◽  
Turbine Engine ◽  
Temperature Mode

Investigation of Vapor-Phase Lubrication in a Gas Turbine Engine

1998 ◽  
Vol 120 (2) ◽  
pp. 257-262 ◽  
Author(s):  
K. W. Van Treuren ◽  
D. N. Barlow ◽  
W. H. Heiser ◽  
M. J. Wagner ◽  
N. H. Forster
Keyword(s):  
Gas Turbine ◽  
Vapor Phase ◽  
Gas Turbine Engine ◽  
Rolling Contact ◽  
Phosphate Ester ◽  
Lubrication System ◽  
Oil Lubrication ◽  
Vapor Phase Lubrication ◽  
Engine Operation ◽  
Turbine Engine

The liquid oil lubrication system of current aircraft jet engines accounts for approximately 10–15 percent of the total weight of the engine. It has long been a goal of the aircraft gas turbine industry to reduce this weight. Vapor-Phase Lubrication (VPL) is a promising technology to eliminate liquid oil lubrication. The current investigation resulted in the first gas turbine to operate in the absence of conventional liquid lubrication. A phosphate ester, commercially known as DURAD 620B, was chosen for the test. Extensive research at Wright Laboratory demonstrated that this lubricant could reliably lubricate rolling element bearings in the gas turbine engine environment. The Allison T63 engine was selected as the test vehicle because of its small size and bearing configuration. Specifically, VPL was evaluated in the number eight bearing because it is located in a relatively hot environment, in line with the combustor discharge, and it can be isolated from the other bearings and the liquid lubrication system. The bearing was fully instrumented and its performance with standard oil lubrication was documented. Results of this baseline study were used to develop a thermodynamic model to predict the bearing temperature with VPL. The engine was then operated at a ground idle condition with VPL with the lubricant misted into the #8 bearing at 13 ml/h. The bearing temperature stabilized at 283°C within 10 minutes. Engine operation was continued successfully for a total of one hour. No abnormal wear of the rolling contact surfaces was found when the bearing was later examined. Bearing temperatures after engine shutdown indicated the bearing had reached thermodynamic equilibrium with its surroundings during the test. After shutdown bearing temperatures steadily decreased without the soakback effect seen after shutdown in standard lubricated bearings. In contrast, the oil-lubricated bearing ran at a considerably lower operating temperature (83°C) and was significantly heated by its surroundings after engine shutdown. In the baseline tests, the final bearing temperatures never reached that of the operating VPL system.

Turbine engine subsystems

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Keyword(s):  
Turbine Engine
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