scholarly journals The INVESTIGATION OF THE DYNAMIC CHARACTERISTICS OF TURBINE IMPELLER DISC OF GAS TURBINE ENGINE USING ANSYS SOFTWARE

Author(s):  
THANH NGOC HUYNH ◽  
TOẢN QUỐC TRẦN ◽  
QUYẾT THÀNH PHẠM

The rotating blades of a compressor or turbine in a gas turbine engine are made up of blades installed on the impeller disc. In particular, the impeller disc needs to be designed, manufactured, and installed to ensure its reliability and safety regarding the strict standards. If damage occurs during the operating process of the impeller disc, it will not only damage the motor but also endanger operators and other equipment. To increase the service time of the engine as well as shorten the production cost, gas turbine manufacturers around the globe are constantly improving technology. In which the monolithic casting impeller is an advanced technology that helps bring down the impeller mass, increasing its life by reducing the shock force on the connection the blades to the rotating disc. Nevertheless, this type of monolithic casting impeller disc reduces its damping effectiveness, which causes the oscillation force to increase significantly. In order to resolve this problem, it is necessary to look into these factors affecting the oscillation of the impeller disc. This paper presents the factors that affect the oscillation of the impeller disc through the study of the dynamic properties of its constituent components. The specific oscillation of the impeller disc, its own oscillation, as well as the impact of factors occurring during the operating of the disc was calculated by using ANSYS simulation software. By creating a three-dimensional model of the turbine blades in gas turbine engine ДP76, the individual oscillation values in a variety of engine operation modes were calculated to compare with the actual value while the engine is operating. The results have good agreement with the measured values. This affirms the advantages and prospects in applying ANSYS software to the design and manufacture of the turbine impeller disc.

Author(s):  
Asfaw Beyene ◽  
Terry Fredlund

Electric, pneumatic, combustion, and hydraulic systems are commonly used as gas turbine engine starters. All such starters must allow full-load engine operation to be reached within few or several minutes, depending on the size and type of the engine. This contrast in the power source of these starters imposes a variation in their operations including control procedures and safety measures such as blow-downs and on/off sequences. Driving characteristics such as dynamic and static behaviors of these starters also vary significantly, depending on the type of starter and the size or configuration (single or multiple shafts) of the engine to be started. This paper provides an overall comparative background of the commonly available gas turbine engine starters. It also presents numerical results comparing hot start characteristics of single, two, and three shaft engines with cold and hot ends. The possibility of a safe engine hot starting is a valid asset in some service areas, mainly military applications. The comparisons include starter power and gas producer speed (NGP) as the function of engine acceleration, and also starter torque as a function of the % NGP. Fuel consumption of the engine during the hot start is simulated and presented as a function of the load. The impact of an engine configuration on engine starting characteristics is implicated.


Author(s):  
Alexandr N. Arkhipov ◽  
Yury A. Ravikovich ◽  
Anton A. Matushkin ◽  
Dmitry P. Kholobtsev

Abstract The regional aircraft with a turbofan gas turbine engine, created in Russia, is successfully operated in the world market. Further increase of the life and reduction of the cost of the life cycle are necessary to ensure the competitive advantages of the engine. One of the units limiting the engine life is the compressor rotor. The cyclic life of the rotor depends on many factors: the stress-strain state in critical zones, the life of the material under low-cycle loading, the regime of engine operation, production deviations (within tolerances), etc. In order to verify the influence of geometry deviations, the calculations of the model with nominal dimensions and the model with the most unfavorable geometric dimensions (worst cases) have been carried out. The obtained influence coefficients for geometric and weight tolerances are then used for probabilistic modeling of stresses in the critical zone. Rotor speed and gas loads on the blades for different flight missions and engine wear are determined from the corresponding aerodynamic calculations taking into account the actual flight cycles (takeoff, reduction, reverse) and are also used for stress recalculations. The subsequent calculation of the rotor cyclic life and the resource assessment is carried out taking into account the spread of the material low-cycle fatigue by probabilistic modeling of the rotor geometry and weight loads. A preliminary assessment of the coefficients of tolerances influence on stress in the critical zone can be used to select the optimal (in terms of life) tolerances at the design stage. Taking into account the actual geometric and weight parameters can allow estimating the stress and expected life of each manufactured rotor.


Author(s):  
G. Paniagua ◽  
C. H. Sieverding ◽  
T. Arts

Advances in turbine-based engine efficiency and reliability are achieved through better knowledge of the mechanical interaction with the flow. The life-limiting component of a modern gas turbine engine is the high-pressure (HP) turbine stage due to the arduous environment. For the same reason, real gas turbine engine operation prevents fundamental research. Various types of experimental approaches have been developed to study the flow and in particular the heat transfer, cooling, materials, aero-elastic issues and forced response in turbines. Over the last 30 years short duration facilities have dominated the research in the study of turbine heat transfer and cooling. Two decades after the development of the von Karman Institute compression tube facility (built in the 90s), one could reconsider the design choices in view of the modern technology in compression, heating, control and electronics. The present paper provides first the history of the development and then how the wind tunnel is operated. Additionally the paper disseminates the experience and best practices in specifically designed measurement techniques to both experimentalists and experts in data processing. The final section overviews the turbine research capabilities, providing details on the required upgrades to the test section.


Author(s):  
J. A. Saintsbury ◽  
P. Sampath

The impact of potential aviation gas turbine fuels available in the near to midterm, is reviewed with particular reference to the small aviation gas turbine engine. The future course of gas turbine combustion R&D, and the probable need for compromise in fuels and engine technology, is also discussed. Operating experience to date on Pratt & Whitney Aircraft of Canada PT6 engines, with fuels not currently considered of aviation quality, is reported.


Author(s):  
Kenneth W. Van Treuren ◽  
D. Neal Barlow ◽  
William H. Heiser ◽  
Matthew J. Wagner ◽  
Nelson H. Forster

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.


2019 ◽  
Vol 55 (1-2) ◽  
pp. 3-9
Author(s):  
A. S. Pugachuk ◽  
V. G. Pribylov ◽  
V. V. Volkov-Muzylev ◽  
V. N. Konoplev

2016 ◽  
Vol 66 (2) ◽  
pp. 193 ◽  
Author(s):  
Anuradha Nayak Majila ◽  
Rajeev Jain ◽  
Chandru Fernando D. ◽  
S. Ramachandra

<p>Studies the impact response of flat Titanium alloy plate against spherical projectile for damage analysis of aero engine components using experimental and finite element techniques. Compressed gas gun has been used to impart speed to spherical projectile at various impact velocities for damage studies. Crater dimensions (diameter and depth) obtained due to impact have been compared with finite element results using commercially available explicit finite element method code LS-DYNA. Strain hardening, high strain rate and thermal softening effect along with damage parameters have been considered using modified Johnson-Cook material model of LS-DYNA. Metallographic analysis has been performed on the indented specimen. This analysis is useful to study failure analysis of gas turbine engine components subjected to domestic object damage of gas turbine engine. </p><p> </p>


Aero Gas Turbine engines power aircrafts for civil transport application as well as for military fighter jets. Jet pipe casing assembly is one of the critical components of such an Aero Gas Turbine engine. The objective of the casing is to carry out the required aerodynamic performance with a simultaneous structural performance. The Jet pipe casing assembly located in the rear end of the engine would, in case of fighter jet, consist of an After Burner also called as reheater which is used for thrust augmentation to meet the critical additional thrust requirement as demanded by the combat environment in the war field. The combustion volume for the After burner operation together with the aerodynamic conditions in terms of pressure, temperature and optimum air velocity is provided by the Jet pipe casing. While meeting the aerodynamic requirements, the casing is also expected to meet the structural requirements. The casing carries a Convergent-Divergent Nozzle in the downstream side (at the rear end) and in the upstream side the casing is attached with a rear mount ring which is an interface between engine and the airframe. The mechanical design parameters involving Strength reserve factors, Fatigue Life, Natural Frequencies along with buckling strength margins are assessed while the Jet pipe casing delivers the aerodynamic outputs during the engine operation. A three dimensional non linear Finite Element analysis of the Jet pipe casing assembly is carried out, considering the up & down stream aerodynamics together with the mechanical boundary conditions in order to assess the Mechanical design parameters.


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