Numerical Simulation of Partial Flame Failure in Gas Turbine Engine

2007 ◽  
Author(s):  
V. Panov ◽  
M. K. D. Smith
Keyword(s):  
Mathematical Model ◽  
Numerical Simulations ◽  
Failure Detection ◽  
Combustion Products ◽  
Detection Algorithm ◽  
Operating Conditions ◽  
Engine Test ◽  
Combustion System ◽  
Turbine Engine ◽  
Model Features

A mathematical model for the simulation of engine start-up thermodynamics has been developed and validated against engine test data. This numerical model has been validated using engine test results for both single and multiple combustor flameouts, and reasonable agreement between test and simulation data has been observed. Numerical simulations have then been generated for flameout cases that have not been available from engine tests, such as flame failure in different combinations of combustors, and at different engine operating conditions. The mathematical model features object modeling of engine components with three gas compositions, being air, fuel, and combustion products. The combustion system has been represented by six combustors, and the gas stream from each combustor has been divided according to the number of the gas path thermocouples downstream from the combustion system. The effects of heat transfer within the combustors and turbine have been modeled. Two sets of thermocouples have been considered, the first being thermocouples installed in multiple combustor burners, and the second being an array of thermocouple probes which are circumferentially positioned in the engine hot gas path. All thermocouples have been modeled as first order dynamic systems. The numerical simulations have been successfully used to support development of a new partial flame failure detection method, which is based on the combined measurements from both sets of thermocouples. A range of numerical simulations have been conducted in order to assess the ability of this new detection algorithm to detect different partial flame failure scenarios, and to examine the sensitivity of the detection algorithm with respect to thermocouples faults.

Exploration of Compact Combustors for Reheat Cycle Aero Engine Applications

2006 ◽  
Author(s):  
J. Zelina ◽  
D. T. Shouse ◽  
J. S. Stutrud ◽  
G. J. Sturgess ◽  
W. M. Roquemore
Keyword(s):  
Gas Turbine ◽  
Temperature Rise ◽  
Gas Turbines ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Combustion System ◽  
Turbine Engine ◽  
Lean Blowout ◽  
Power Extraction ◽  
Wide Range

An aero gas turbine engine has been proposed that uses a near-constant-temperature (NCT) cycle and an Inter-Turbine Burner (ITB) to provide large amounts of power extraction from the low-pressure turbine. This level of energy is achieved with a modest temperature rise across the ITB. The additional energy can be used to power a large geared fan for an ultra-high bypass ratio transport aircraft, or to drive an alternator for large amounts of electrical power extraction. Conventional gas turbines engines cannot drive ultra-large diameter fans without causing excessively high turbine temperatures, and cannot meet high power extraction demands without a loss of engine thrust. Reducing the size of the combustion system is key to make use of a NCT gas turbine cycle. Ultra-compact combustor (UCC) concepts are being explored experimentally. These systems use high swirl in a circumferential cavity about the engine centerline to enhance reaction rates via high cavity g-loading on the order of 3000 g’s. Any increase in reaction rate can be exploited to reduce combustor volume. The UCC design integrates compressor and turbine features which will enable a shorter and potentially less complex gas turbine engine. This paper will present experimental data of the Ultra-Compact Combustor (UCC) performance in vitiated flow. Vitiation levels were varied from 12–20% oxygen levels to simulate exhaust from the high pressure turbine (HPT). Experimental results from the ITB at atmospheric pressure indicate that the combustion system operates at 97–99% combustion efficiency over a wide range of operating conditions burning JP-8 +100 fuel. Flame lengths were extremely short, at about 50% of those seen in conventional systems. A wide range of operation is possible with lean blowout fuel-air ratio limits at 25–50% below the value of current systems. These results are significant because the ITB only requires a small (300°F) temperature rise for optimal power extraction, leading to operation of the ITB at near-lean-blowout limits of conventional combustor designs. This data lays the foundation for the design space required for future engine designs.

Prognostics Model for Predicting Aero-Engine Bearing Grade-Life

2009 ◽  
Author(s):  
Jie Hong ◽  
Xuewen Miao ◽  
Lei Han ◽  
Yanhong Ma
Keyword(s):  
Mathematical Model ◽  
Service Life ◽  
Critical Role ◽  
Operating Conditions ◽  
Life Assessment ◽  
Prognostic Models ◽  
Turbine Engine ◽  
Final Grade ◽  
Failure Data ◽  
Engine Bearing

Development of practical and verifiable prognostic approaches for service life of gas turbine engine bearings will play a critical role in improving the reliability and safety of aircraft engines. Upgrading current military aeroengine overhaul metrics based strictly on engine flight hours and total accumulated cycles with higher fidelity prognostic models will provide an opportunity to prevent failures caused by accelerated degradation due to operation in unusually harsh conditions, and will help avoid unnecessary maintenance caused by routine check on engines that operate under nominal operating conditions. Grade-life (GL) is used to describe the bearing’s service life, and a comprehensive engine bearing prognostic model comprised of a physics based mathematical model and a prognostic element is presented in this paper. The mathematical model utilizes information from the Sensed Data module to calculate the cumulative damage sustained by the bearing since it was first installed and the Prediction Grade-life (PGL) is captured. The prognostic estimate model is an empirical lifetime model, in which Empirical Grade-life (EGL) is assessed based on vibration signals intelligently. The final Grade-life of bearings is determined by fusion of analytic Grade-life (PGL) and Grade-life assessment value (EGL) based on Fuzzy Logic Inference, which reduces the uncertainty’s affection towards prediction results of the analytic model. Finally, bearing test stand run-to-failure data is used to verify the approach.

Feasibility of Utilizing a Bio-Mass Derived Fuel for Industrial Gas Turbine Applications

1995 ◽  
Author(s):  
R. G. Andrews ◽  
P. C. Patnaik ◽  
J. W. Michniewicz ◽  
L. J. Jankowski ◽  
V. I. Romanov ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Development Program ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Combustion System ◽  
Test Vehicle ◽  
Heating Value ◽  
Turbine Engine ◽  
Standard Operating ◽  
Industrial Gas Turbine

This paper describes a development program aimed at determining the technical feasibility of utilizing a bio-mass derived fuel in an industrial gas turbine engine. The fuel addressed is a flammable bio-fuel oil derived from wood waste through flash pyrolysis. The fuel has a heating value of approximately 18 MJ/kg, a density of 1.2 kg/l and specialized wet filtration techniques are used to minimize the particulate matter in the fuel. The turbine engine selected, as the test vehicle, is a 2.5 MW class-GT2500 engine designed and built by Mashproekt in the Ukraine. The standard operating conditions and layout of this engine provide flexibility in optimization of the combustion system to accept lower than conventional grade fuels. The characteristics of the fuel, the fuel handling system, and the considerations with respect to igniting and maintaining combustion with a fuel of this nature are discussed.

scholarly journals Fuel Property Effects on Life Characteristics of Aircraft Turbine Engine Combustors

1980 ◽  
Author(s):  
C. C. Gleason ◽  
D. W. Bahr
Keyword(s):  
Hydrogen Content ◽  
Operating Conditions ◽  
Advanced Technology ◽  
Combustion System ◽  
Fuel Property ◽  
Turbine Engine ◽  
Electric Aircraft ◽  
Cooling Design ◽  
Life Predictions ◽  
Combustor Liner

Results of a program to determine the effects of fuel properties on the life characteristics of two USAF/General Electric aircraft turbine engine combustors are presented. Thirteen test fuels were evaluated in an older technology cannular combustion system (J79) and in an advanced technology, virtually smokeless, compact, annular combustion system (F101) over wide ranges of simulated engine operating conditions. Fuel variables were hydrogen content, aromatic structure, volatility and distillation end point. Significant increases in combustor liner temperatures were observed as fuel hydrogen content was decreased. With fuel hydrogen contents of 14.5, 14.0, 13.0 and 12.0, the resulting relative combustor liner cyclic life predictions are 1.00, 0.78, 0.52, and 0.35 for the J79 combustor and 1.00, 0.72, 0.52 and 0.47 for the F101 combustor, respectively. Based on these findings, it is concluded that improved liner cooling design features will be needed in most current technology combustors to accommodate the projected lower hydrogen contents of future fuels.

Thermofluid Dynamic Analysis of a Gas Turbine Transition-Piece

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Antonio Andreini ◽  
Lorenzo Mazzei ◽  
Giovanni Riccio ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Combustion Products ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Thermal Loads ◽  
Gas Generator ◽  
Fixed Temperature ◽  
Turbine Engine ◽  
Transition Piece

The transition-piece of a gas turbine engine is subjected to high thermal loads as it collects high temperature combustion products from the gas generator to a turbine. This generally produces high thermal stress levels in the casing of the transition piece, strongly limiting its life expectations and making it one of the most critical components of the entire engine. The reliable prediction of such thermal loads is hence a crucial aspect to increase the transition-piece life span and to assure safe operations. The present study aims to investigate the aerothermal behavior of a gas turbine engine transition-piece and in particular to evaluate working temperatures of the casing in relation to the flow and heat transfer situation inside and outside the transition-piece. Typical operating conditions are considered to determine the amount of heat transfer from the gas to the casing by means of computational fluid dynamics (CFD). Both conjugate approach and wall fixed temperature have been considered to compute the heat transfer coefficient (HTC), and more in general, the transition-piece thermal loads. Finally a discussion on the most convenient HTC expression is provided.

Validation of mathematical model of electrothermal calculation of DC catenary on the basis of scale model

2018 ◽  
Vol 77 (4) ◽  
pp. 222-229 ◽  
Author(s):  
A. V. Paranin ◽  
A. B. Batrashov
Keyword(s):  
Mathematical Model ◽  
Operating Conditions ◽  
Scale Model ◽  
Contact Network ◽  
Scaled Model ◽  
Cross Sectional ◽  
Current Collection ◽  
Topological Features ◽  
Study Results ◽  
Real Physical Process

The article compares the results of calculation of the finite element simulation of current and temperature distribution in the scale model of the DC catenary with the data of laboratory tests. Researches were carried on various versions of the structural design of catenary model, reflecting the topological features of the wire connection, characteristic of the DC contact network. The proportions of the cross-sectional area of the scaled model wires are comparable to each other with the corresponding values for real DC catenary. The article deals with the operating conditions of the catenary model in the modes of transit and current collection. When studying the operation of the scale catenary model in the transit mode, the effect of the structural elements on the current distribution and heating of the wires was obtained. Within the framework of the scale model, theoretical assumptions about the current overload of the supporting cable near the middle anchoring have been confirmed. In the current collection mode, the experimental dependences of the current in the transverse wires of the scale model are obtained from the coordinate of the current collection point. Using the model it was experimentally confirmed that in the section of the contact wire with local wear, not only the temperature rise occurs but also the current redistribution due to the smaller cross section. Thus, the current share in other longitudinal wires of the scale model increases and their temperature rises. Scale and mathematical models are constructed with allowance for laboratory clamps and supporting elements that participate in the removal of heat from the investigated wires. Obtained study results of the scale model allow to draw a conclusion about the adequacy of the mathematical model and its correspondence to the real physical process. These conclusions indicate the possibility of applying mathematical model for calculating real catenary, taking into account the uneven contact wear wire and the armature of the contact network.

scholarly journals Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Luqman S. Maraaba ◽  
Zakariya M. Al-Hamouz ◽  
Abdulaziz S. Milhem ◽  
Ssennoga Twaha
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
High Efficiency ◽  
Experimental Tests ◽  
Induction Machines ◽  
Test Methods ◽  
Operating Conditions ◽  
Test Method ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.

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