Experimental Studies of the Boundary Conditions Leading to Oil Fire in the Bearing Chamber and in the Secondary Air System of Aeroengines

2002 ◽  
Author(s):  
K. Willenborg ◽  
S. Busam ◽  
H. Roßkamp ◽  
S. Wittig
Keyword(s):  
High Reliability ◽  
Experimental Studies ◽  
Spontaneous Ignition ◽  
Fundamental Study ◽  
Engine Operation ◽  
Continuous Increase ◽  
Hot Surface Ignition ◽  
Air System ◽  
Secondary Air ◽  
Hot Surface

The continuous increase of the temperature and pressure levels in modern aeroengines has significantly increased the demands on the design of the lubrication system. Among other things the oil/air system of a gas turbine engine has to ensure that engine operation does not permit oil coking or oil fires in order to guarantee high reliability and safety of the engine. To improve existing and develop new design rules, a fundamental study of the conditions leading to oil firing within an oil contaminated environment has been initiated. Three ignition mechanisms relevant for the triggering of an oil fire in the bearing chamber or in the secondary air system are investigated in detail: the spontaneous ignition of the lubricant (autoignition), the ignition of the lubricant near a hot surface (hot surface ignition) and the propagation of a flame within a vent pipe into the bearing chamber (vent pipe flashback). The present paper focusses on the experimental approach and procedure. The different test rigs are presented and their functioning is demonstrated by means of initial results.

Development of a Novel Flow Control Device for Limiting the Efflux of Air Through a Failed Pipe

2009 ◽  
Author(s):  
T. Scanlon ◽  
P. Wilson ◽  
G. Priestman ◽  
J. Tippetts
Keyword(s):  
Gas Turbine ◽  
High Reliability ◽  
Pressure Ratio ◽  
Control Flow ◽  
Pipe Failure ◽  
Low Resistance ◽  
Air System ◽  
Resistance State ◽  
Secondary Air ◽  
Moving Parts

The secondary air-systems of a gas turbine engine frequently incorporate pipes and ducts to transport air for duties such as cooling and sealing of the turbine components, pressurisation of the aircraft cabin and component de-icing. The engine must be capable of operating safely in the event of failure of a pipe or duct. The ducts typically pass through the low pressure ventilation zones outboard of the core engine and failure will result in a large mass flow of relatively high temperature air escaping from the secondary air system; the design of the engine must accommodate this potential escape so that no component is over-pressurised or over-heated as a result. A novel device is presented that will limit the flow that escapes in the event of a pipe failure. This device has been developed from a number of flow elements from Fluidic technology applications. It has no moving parts and is thus suitable for use as a high-reliability failure protection device. The device consists of a Coanda diverter that can switch the flow through a vortex throttle so that the device has high and low resistance states. The diverter is conditioned to default to the low resistance state unless a control flow extracted from the device exceeds a critical value whereupon it will switch the device to a high resistance state. The level of the control flow is determined by the pressure ratio acting across the device. This is achieved by contrasting the flow characteristics of a metering orifice that determines the control flow with that of a diffuser fitted to the device outlet. The device has been shown to half the flow that escapes from a failed duct compared with an unrestricted duct of the same flow capacity. Experimental and numerical results are presented that show that the device is effective at the high pressure ratios pertaining to gas turbine operation. With suitable modification the device could be adapted to fulfill a number of other functions within a secondary air-system that require variation of flow resistance in response to a change in pressure ratio combined with the high reliability and robustness of a no-moving-parts device.

DIESEL ENGINE OPERATION IN USE OF FUEL WITH ADDITIVES

2018 ◽  
pp. 18-24
Author(s):  
Petar Kazakov ◽  
Atanas Iliev ◽  
Emil Marinov
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Diesel Fuel ◽  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Combustion Engines ◽  
Engine Operation ◽  
Factors Affecting ◽  
Operating Modes ◽  
Positive Effects

Over the decades, more attention has been paid to emissions from the means of transport and the use of different fuels and combustion fuels for the operation of internal combustion engines than on fuel consumption. This, in turn, enables research into products that are said to reduce fuel consumption. The report summarizes four studies of fuel-related innovation products. The studies covered by this report are conducted with diesel fuel and usually contain diesel fuel and three additives for it. Manufacturers of additives are based on already existing studies showing a 10-30% reduction in fuel consumption. Comparative experimental studies related to the use of commercially available diesel fuel with and without the use of additives have been performed in laboratory conditions. The studies were carried out on a stationary diesel engine СМД-17КН equipped with brake КИ1368В. Repeated results were recorded, but they did not confirm the significant positive effect of additives on specific fuel consumption. In some cases, the factors affecting errors in this type of research on the effectiveness of fuel additives for commercial purposes are considered. The reasons for the positive effects of such use of additives in certain engine operating modes are also clarified.

scholarly journals Hot Surface Ignition of A Composite Fuel Droplet

2015 ◽  
Vol 23 ◽  
pp. 01063 ◽  
Author(s):  
Dmitrii O. Glushkov ◽  
Pavel A. Strizhak ◽  
Ksenia Yu. Vershinina
Keyword(s):  
Fuel Droplet ◽  
Hot Surface Ignition ◽  
Surface Ignition ◽  
Composite Fuel ◽  
Hot Surface

ANALYSIS OF THE ERROR IN DETERMINING THE EQUIVALENT SIZE OF A DEFECT BY THE STANDARDLESS METHOD DURING ULTRASONIC TESTING

2021 ◽  
pp. 50-57
Author(s):  
A. N. Kireev ◽  
M. A. Kireeva
Keyword(s):  
Relative Error ◽  
High Reliability ◽  
Ultrasonic Method ◽  
Experimental Studies ◽  
Standard Samples ◽  
Defect Identification ◽  
Identification Method ◽  
Maximum Value ◽  
Software Product ◽  
The Relationship

The article provides a review and analysis of the defect identification method for determining the size of discontinuities when diagnosing various machine parts and units by the manual ultrasonic method. This method makes it possible to determine the equivalent size of discontinuities of various types without using standard samples of an enterprise: point planar and volumetric; extended planar and volumetric. The method is based on the use of the relationship between the amplitude and time characteristics of the echo signal from the discontinuity and the backside signal in the object being diagnosed and the equivalent size of the discontinuity. The article presents the mathematical apparatus for the implementation of this method. Also presented is a software product that allows you to automate calculations when using this defect identification method. The article contains experimental studies of the method for determining the equivalent dimensions of discontinuities of various types, which have shown its high reliability. The maximum value of the relative error in determining the equivalent size of a point planar discontinuity was 2.867 %. The maximum value of the relative error in determining the equivalent size of a point volumetric discontinuity was 1.986 %. The maximum value of the relative error in determining the transverse equivalent size of an extended planar discontinuity was 0.667 %. The maximum value of the relative error in determining the transverse equivalent size of an extended volumetric discontinuity was 1.95 %.

Virtual Gas Turbines Part II: an Automated Whole-Engine Secondary Air System Model Generation

2021 ◽  
Author(s):  
Davendu Y. Kulkarni ◽  
Luca di Mare
Keyword(s):  
Gas Turbine ◽  
Network Model ◽  
Design Analysis ◽  
Model Generation ◽  
Time Cost ◽  
Flow Network ◽  
Turbine Engine ◽  
Geometry Model ◽  
Air System ◽  
Secondary Air

Abstract The design and analysis of the secondary air system (SAS) of gas turbine engine is a complex and time-consuming process because of its complicated geometry topology. The conventional SAS design-analysis model generation process is quite tedious, time consuming. It is still heavily dependent on human expertise and thus incurs high time-cost. This paper presents an automated, whole-engine SAS flow network model generation methodology. During the SAS preprocessing step, the method accesses a pre-built whole-engine geometry model created using a novel, in-house, feature-based geometry modelling environment. It then transforms the engine geometry features into the features suitable for SAS flow network analysis. The proposed method not only extracts the geometric information from the computational geometry but also retrieves additional non-geometric attributes such as, rotational frames, boundary types, materials and boundary conditions etc. Apart from ensuring geometric consistency, this methodology also establishes a bi-directional information exchange protocol between engine geometry model and SAS flow network model, which enables making engine geometry modifications based on SAS analysis results. The application of this feature mapping methodology is demonstrated by generating the secondary air system (SAS) flow network model of a modern three-shaft gas turbine engine. This capability is particularly useful for the integration of geometry modeler with the simulation framework. The present SAS model is generated within a few minutes, without any human intervention, which significantly reduces the SAS design-analysis time-cost. The proposed method allows performing a large number of whole-engine SAS simulations, design optimisations and fast re-design activities.

scholarly journals The Effect of Catalytic Reaction on Hot Surface Ignition

1997 ◽  
Vol 63 (611) ◽  
pp. 2539-2544 ◽  
Author(s):  
Hyungman KIM ◽  
Hiroshi ENOMOTO ◽  
Hideki KATO ◽  
Mitsuhiro TSUE ◽  
Michikata KONO
Keyword(s):  
Catalytic Reaction ◽  
Hot Surface Ignition ◽  
Surface Ignition ◽  
Hot Surface

Hot Surface Ignition of Performance Fuels

2009 ◽  
Vol 46 (2) ◽  
pp. 363-374 ◽  
Author(s):  
Scott Davis ◽  
Sean Kelly ◽  
Vijay Somandepalli
Keyword(s):  
Hot Surface Ignition ◽  
Surface Ignition ◽  
Hot Surface

Secondary Air Systems in Aeroengines Employing Vortex Reducers

2001 ◽  
Author(s):  
Dimitrie Negulescu ◽  
Michael Pfitzner
Keyword(s):  
Flow Path ◽  
Supporting Evidence ◽  
Excessive Pressure ◽  
Pressure Losses ◽  
Low Pressure Turbine ◽  
Hot Gas ◽  
Air System ◽  
High Integrity ◽  
Secondary Air ◽  
Aero Engines

A secondary air system in modern aero engines is required to cool the compressor and turbine discs and make sure that no hot gas ingestion occurs into the cavities between the turbine discs, which could cause an inadvertent reduction of disc life. A high integrity solution for guiding the air from the compressor to the turbine is through an inner bleed from the compressor platform and through the space between the disc bores and the shaft connecting the fan with the low pressure turbine. Since strongly swirling air is taken from the compressor platforms to a much lower radius, a means of deswirling the air has to be used to avoid excessive pressure losses along the flow path. The paper describes a system utilizing tubeless vortex reducers to accomplish this deswirl, which are compared to a more conventional air system utilizing tubes. The working principles of both types of vortex reducer and guidelines for the design of a secondary air system using vortex reducers are explained with supporting evidence from rig tests and CFD calculations. Opportunities for the aerodynamic optimisation of the tubeless vortex reducer are elaborated and the experience gained using the system during the development of the BR700 engine is described.

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