scholarly journals Analysis of the operating load of foil-air bearings in the gas generator of the turbine engine during the acceleration and deceleration maneuver

2016 ◽  
Vol 18 (4) ◽  
pp. 507-513 ◽  
Author(s):  
Zbigniew Czyż ◽  
Paweł Magryta
Keyword(s):  
Air Bearings ◽  
Gas Generator ◽  
Turbine Engine ◽  
Operating Load ◽  
Acceleration And Deceleration

scholarly journals ANALYSIS OF THE OPERATING LOAD OF THE TURBINE ENGINE DURING DECELERATION TO DASH MANEUVER

2016 ◽  
Vol 2 (1) ◽  
pp. 66-72
Author(s):  
Zbigniew Czyż
Keyword(s):  
Least Squares ◽  
Least Squares Method ◽  
Unmanned Helicopter ◽  
Gas Generator ◽  
Turbine Engine ◽  
Operating Load ◽  
Acceleration And Deceleration ◽  
Bearing Assembly ◽  
Velocity Changes ◽  
Engine Power

The article presents the analysis of the loads on the gas generator of turbine engine power of unmanned helicopter. The analysis was performed for deceleration to dash maneuver. Particular attention was paid to loads of bearing assembly in gas generator of turbine engine. The analysis was based on the timelines of changes in velocity of manned helicopter PZL W3-Falcon. The dependence of velocity changes during the flight was made as approximation by the least squares method and then determined for its change in acceleration. On this basis, the forces acting on the bearing gas generator assembly in static and dynamic conditions were determined. These values were compared with values obtained during maneuvers such as "jump up and jump down" and "acceleration and deceleration maneuver".

Advanced Technology Programs for Small Turboshaft Engines: Past, Present, Future

1991 ◽  
Vol 113 (1) ◽  
pp. 33-39 ◽  
Author(s):  
E. T. Johnson ◽  
H. Lindsay
Keyword(s):  
United States Army ◽  
High Performance ◽  
The United States ◽  
Modern Technology ◽  
Advanced Technology ◽  
Gas Generator ◽  
Turbine Engine ◽  
Technology Programs ◽  
Aircraft Propulsion System ◽  
Year 2000

This paper addresses approximately 15 years of advanced technology programs sponsored by the United States Army Aviation Applied Technology Directorate and its predecessor organizations and conducted by GE Aircraft Engines (GEAE). Included in these programs is the accomplishment of (1) the 1500 shp demonstrator (GE12), which led to the 1700, and (2) the 5000 shp Modern Technology Demonstrator Engine (MTDE/GE27). Also included are several advanced technology component programs that have been completed or are ongoing through the early 1990s. The goals for the next generation of tri-service small advanced gas generator demonstration programs are shown. A prediction is thus made of the advancements required to fulfill the aircraft propulsion system established by the DoD/NASA Integrated High-Performance Turbine Engine Technology (IHPTET) initiative through the year 2000.

Development of Dry Low-NOx Combustor for 300 kW Class Gas Turbine Applied to Co-Generation Systems

2001 ◽  
Author(s):  
Yoichiro Ohkubo ◽  
Osamu Azegami ◽  
Hiroshi Sato ◽  
Yoshinori Idota ◽  
Shinichiro Higuchi
Keyword(s):  
Gas Turbine ◽  
Output Power ◽  
Combustion Efficiency ◽  
Gas Generator ◽  
Turbine Engine ◽  
Partial Load ◽  
Wide Range ◽  
Compressor Inlet ◽  
Endurance Testing ◽  
Turbine Speed

A 300 kWe class gas turbine which has a two-shaft and simple-cycle has been developed to apply to co-generation systems. The gas turbine engine is operated in the range of about 30% partial load to 100% load. The gas turbine combustor requires a wide range of stable operations and low NOx characteristics. A double staged lean premixed combustor, which has a primary combustion duct made of Si3N4 ceramics, was developed to meet NOx regulations of less than 80 ppm (corrected at 0% oxygen). The gas turbine with the combustor has demonstrated superior low-emission performance of around 40 ppm (corrected at 0% oxygen) of NOx, and more than 99.5% of combustion efficiency between 30% and 100% of engine load. Endurance testing has demonstrated stable high combustion performance over 3,000 hours in spite of a wide compressor inlet air temperature (CIT) range of 5 to 35 degree C.. While increasing the gas generator turbine speed, the flow rate of primary fuel was controlled to hold a constant equivalence ratio of around 0.5 in the CIT range of more than 15 C. The output power was also decreased while increasing the CIT, in order to keep a constant temperature at the turbine inlet. The NOx decreases in the CIT range of more than 15 C. On the other hand, the NOx increases in the CIT range of less than 15 C when the output power was kept a constant maximum power. As a result, NOx emission has a peak value of about 40 ppm at 15 C.

scholarly journals A Parametric Starting Study of an Axial-Centrifugal Gas Turbine Engine Using a One-Dimensional Dynamic Engine Model and Comparisons to Experimental Results: Part 1 — Model Development and Facility Description

1998 ◽  
Author(s):  
A. Karl Owen ◽  
Anne Daugherty ◽  
Doug Garrard ◽  
Howard C. Reynolds ◽  
Richard D. Wright
Keyword(s):  
Gas Turbine ◽  
Initial Conditions ◽  
Model Development ◽  
Ground Level ◽  
Gas Turbine Engine ◽  
Calibration Data ◽  
Gas Generator ◽  
Turbine Engine ◽  
One Dimensional ◽  
Engine Model

A generic one-dimensional gas turbine engine model, developed at the Arnold Engineering Development Center, has been configured to represent the gas generator of a General Electric axial-centrifugal gas turbine engine in the six kg/sec airflow class. The model was calibrated against experimental test results for a variety of initial conditions to insure that the model accurately represented the engine over the range of test conditions of interest. These conditions included both assisted (with a starter motor) and unassisted (altitude windmill) starts. The model was then exercised to study a variety of engine configuration modifications designed to improve its starting characteristics and thus quantify potential starting improvements for the next generation of gas turbine engines. This paper discusses the model development and describes the test facilities used to obtain the calibration data. The test matrix for the ground level testing is also presented. A companion paper presents the model calibration results and the results of the trade-off study.

Test Experience With Turbine-End Foil Bearing Equipped Gas Turbine Engines

1983 ◽  
Author(s):  
F. J. Suriano ◽  
R. D. Dayton ◽  
Fred G. Woessner
Keyword(s):  
Gas Turbine ◽  
Thermal Environment ◽  
Full Range ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Engine Test ◽  
Gas Generator ◽  
Turbine Engine ◽  
Foil Bearings ◽  
Foil Bearing

The Garrett Turbine Engine Company, a Division of the Garrett Corporation, authorized under Air Force Contract F33615-78-C-2044 and Navy Contract N00140-79-C-1294, has been conducting development work on the application of gas-lubricated hydrodynamic journal foil bearings to the turbine end of gas turbine engines. Program efforts are directed at providing the technology base necessary to utilize high-temperature foil bearings in future gas turbine engines. The main thrust of these programs was to incorporate the designed bearings, developed in test rigs, into test engines for evaluation of bearing and rotor system performance. The engine test programs included a full range of operational tests; engine thermal environment, endurance, start/stops, attitude, environmental temperatures and pressures, and simulated maneuver bearing loadings. An 88.9 mm (3.5-inch) diameter journal foil bearing, operating at 4063 RAD/SEC (38,800 rpm), has undergone test in a Garrett GTCP165 auxiliary power unit. A 44.4 mm (1.75-inch) diameter journal foil bearing, operating at 6545 RAD/SEC (62,500 rpm) has undergone test in the gas generator of the Garrett Model JFS190. This paper describes the engine test experience with these bearings.

Unbalance Response of a Two Spool Gas Turbine Engine With Squeeze Film Bearings

1981 ◽  
Author(s):  
E. J. Gunter ◽  
D. F. Li ◽  
L. E. Barrett
Keyword(s):  
Gas Turbine ◽  
Nonlinear Effects ◽  
Forced Response ◽  
Squeeze Film ◽  
Gas Generator ◽  
Main Bearing ◽  
Resonant Condition ◽  
Turbine Engine ◽  
Generator Rotor ◽  
Power Turbine

This paper presents a dynamic analysis of a two-spool gas turbine helicopter engine incorporating intershaft rolling element bearings between the gas generator and power turbine rotors. The analysis includes the nonlinear effects of a squeeze film bearing incorporated on the gas generator rotor. The analysis includes critical speeds and forced response of the system and indicates that substantial dynamic loads may be imposed on the intershaft bearings and main bearing supports with an improperly designed squeeze film bearing. A comparison of theoretical and experimental gas generator rotor response is presented illustrating the nonlinear characteristics of the squeeze film bearing. It was found that large intershaft bearing forces may occur even though the engine is not operating at a resonant condition.

Experimental and Theoretical Studies of a Novel Venturi LPP Combustor

2000 ◽  
Author(s):  
Nils A. Røkke ◽  
Andrew J. W. Wilson
Keyword(s):  
Pressure Drop ◽  
Gas Turbine ◽  
Liquid Fuel ◽  
Gas Generator ◽  
Turbine Engine ◽  
Throat Region ◽  
Low Emission ◽  
Lean Premixed ◽  
Fuel Staging ◽  
Performance And Emissions

A new gas turbine engine using a unique layout patented in Norway has a low emission combustion system under development. The gas generator uses entirely radial rotating components and employs a dual entry LP radial compressor, a radial HP compressor and a radial HP turbine. The power turbine is of a two stage axial design, coupled to an epicyclical gear embedded in the exhaust duct. Several combustor concepts have been tested and evaluated during the development of the engine. The engine is targeted for marine, power generation and train propulsion. For the marine and train application liquid fuel operation is needed, thus the primary focus in the development has been for a lean premixed prevapourised system. An interesting concept utilising two venturi premixers has been studied intensively. By utilising venturi premixers the following advantages can be achieved: • Low overall pressure drop but high injector pressure drop and velocities in the mixing region (throat region) • High shear forces and drag imposed on the droplets enhancing droplet shedding and evaporation • Excellent emission behaviour at designated load conditions Although these advantages can benefit gas turbine low emission combustion the challenges in using venturi premixers are: • Venturis are susceptible to separation and thus flame stabilisation within the venturi which is detrimental • Inlet flow disturbances enhance the tendency for separation in the venturis and must be minimised Studies were launched to investigate a proposed combustor configuration. These studies included analytical studies, Computational Fluid Dynamics (CFD) calculations of isothermal and combusting flow inside the combustor together with rig tests at atmospheric, medium and full pressure. Finally engine tests within the full operating range were conducted with very favourable emission figures for Lean Premixed Prevapourised (LPP) operation. The system was capable of running at below 20 ppm Nox and CO, at elevated power for liquid fuel. Control of part load performance and emissions is by variable fuel staging of the two venturi stages. The paper highlights the features of the venturi combustor development and discusses the characteristics in terms of flow conditions and droplet motion, heat transfer, ignition delay time and emissions.

The Co-Turboshaft: A Novel Gas Turbine Powerplant for Heavy Equipment

1979 ◽  
Author(s):  
D. A. J. Millar ◽  
M. S. Chappell ◽  
R. Okelah
Keyword(s):  
Gas Turbine ◽  
Control Strategies ◽  
Output Shaft ◽  
Speed Ratio ◽  
Inlet Temperature ◽  
Gas Generator ◽  
Turbine Engine ◽  
Engine Torque ◽  
Performance Effects ◽  
Turboshaft Engine

A major advantage of the two-shaft gas turbine as a prime mover is the steep torque-speed characteristic, so that the stall torque is typically twice the design torque. The co-turboshaft engine has a torque-speed curve which can be more than twice as steep as the conventional engine, so that only a rudimentary transmission would be required for normal operations. The co-turboshaft gas turbine engine has a co-rotating compressor case which is geared, together with the free power turbine, to the output shaft. As load increases and output shaft speed decreases, the effective gas generator speed increases, with no increase in rotor speed, and the power output rises. The engine has a torque-speed curve with up to four times the slope of a conventional free shaft turbine engine torque curve. This paper reviews results of testing a compressor with a co-rotating casing, and presents the results of simulating a typical engine using a hybrid computer to predict engine steady state performance. Effects of different design choices of compressor casing speed ratio are shown on engine torque, power and turbine inlet temperature characteristics. Control strategies for some possible applications, such as off-road vehicles and construction equipment, are discussed in relation to their likely duty cycles.

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