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Desenvolvimento de um compressor radial para turbina a gás de pequeno porte.; Development of a radial compressor for a small gas turbine.

Campos, André Perpignan Viviani de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/03/2013 PT
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O desenvolvimento de tecnologia na área de turbomáquinas é essencial ao desenvolvimento da indústria nacional e o Laboratório de Engenharia Ambiental e Térmica da Escola Politécnica da Universidade de São Paulo tem compreendido ações para este propósito. Este trabalho tem por objetivo desenvolver um compressor para uma turbina a gás de pequeno porte de 500 kW, primeiro passo para o projeto e construção da turbina como um todo. A partir da análise do ciclo termodinâmico e da análise de adimensionais, o tipo de compressor a ser utilizado foi determinado. Optou-se pelo projeto de um compressor centrífugo. Iniciou-se o projeto através de análise e correlações unidimensionais com previsão de desempenho, definindo algumas geometrias iniciais a serem avaliadas nas fases seguintes. Realizou-se a análise bidimensional do impelidor com a ferramenta computacional Vista TF que utiliza o método de curvatura de linhas de corrente. Por fim, a geometria tridimensional foi definida com uso de simulações de dinâmica de fluidos computacional. De acordo com as simulações, o compressor projetado tem desempenho condizente com os requisitos impostos.; Technology development in turbomachinery is essential to the national industry development and the Laboratory of Environmental and Thermal Engineering of the Polytechnic School of the University of São Paulo is engaged on this purpose. This work intends to design a compressor for a small 500 kW gas turbine...

Análise do comportamento de grandezas e parâmetros que determinam o dimensionamento de turbomáquinas a vapor

Tofoli, Fabio
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 82 f. : il.
POR
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Engenharia Mecânica - FEG; Este trabalho tem como objetivo a análise da influência de parâmetros adimensionais e grandezas dimensionais no projeto de turbomáquinas operando em diferentes situações de pressão, temperatura e vazão mássica de vapor. O trabalho é divido em duas partes principais, sendo que inicialmente são analisados os parâmetros adimensionais e as grandezas dimensionais que influenciam diretamente o valor do rendimento interno das turbomáquinas térmicas que utilizam o vapor como fluido de trabalho. Na segunda parte do trabalho são abordadas as classes de pressão e rotação específica, e sua influência no comportamento de parâmetros adimensionais. A aplicação dos resultados está diretamente ligada a especificação de turbomáquinas em sistemas de cogeração para aproveitamento de fluxos térmicos provenientes de processos, queima de combustíveis ou gases de escape de uma máquina térmica, para os quais os projetistas necessitam estimar o rendimento de tais componentes por ocasião da análise de viabilidade econômica.; This work has as objective the analysis of the influence of dimensionless parameters and dimensional greatness in the project of turbomachinery operating in different pressure situations...

Modeling, design and analysis of micro-scale Rankine-based systems

Cui, Ling, 1978-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 149 p.; 7830481 bytes; 7847204 bytes; application/pdf; application/pdf
ENG
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This thesis presents the modeling and design of two major types of micro Rankine-cycle-based machines: a single-Rankine-based power system and a waste-heat-driven cooler. As part of the Massachusetts Institute of Technology (MIT) Micro Engine Project, these projected machines can be combined with the MIT micro gas turbine engines to improve their overall performance. The models were based on the conventional heat transfer and fluid mechanics correlations. And the state-of-the-art turbomachinery technologies and fabrication capability were taken into consideration in the designing of these devices. The results show that the single-Rankine bottoming power system could provide as high as 37-watt power when it is combined with a micro gas turbine engine, given a one square inch footprint and 50% turbomachinery efficiency. The waste-heat-driven cooler, or the heat pump, could provide air-conditioning and condensed water when it is combined to a micro gas turbine engine. Within a footprint of 7 cm by 7 cm, it could generate a 25-watt total cooling power. The amount of effective cooling (air-conditioning) power and condensed water is highly dependent on the ambient temperature and humidity. Micro heat exchanger designs for the above Rankine machines were also delineated in this thesis. The traditional fin-type heat exchanger and a new low-pressure-drop hole-type heat exchanger were discussed. All of these heat exchangers are within the realm of the state-of-the-art fabrication capabilities. At the end of the thesis...

Development of a MEMS turbocharger and gas turbine engine; Development of a microelectromechanical systems turbocharger and gas turbine engine

Savoulides, Nicholas, 1978-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 308 p.; 14653135 bytes; 14675855 bytes; application/pdf; application/pdf
ENG
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As portable electronic devices proliferate (laptops, GPS, radios etc.), the demand for compact energy sources to power them increases. Primary (non-rechargeable) batteries now provide energy densities upwards of 180 W-hr/kg, secondary (rechargeable) batteries offer about 1/2 that level. Hydrocarbon fuels have a chemical energy density of 13,000-14,000 W-hr/kg. A power source using hydrocarbon fuels with an electric power conversion efficiency of order 10% would be revolutionary. This promise has driven the development of the MIT micro gas turbine generator concept. The first engine design measures 23 x 23 x 0.3 mm and is fabricated from single crystal silicon using MEMS micro-fabrication techniques so as to offer the promise of low cost in large production. This thesis describes the development and testing of a MEMS turbocharger. This is a version of a simple cycle, single spool gas turbine engine with compressor and turbine flow paths separated for diagnostic purposes, intended for turbomachinery and rotordynamic development. The turbocharger design described herein was evolved from an earlier, unsuccessful design (Protz 2000) to satisfy rotordynamic and fabrication constraints. The turbochargers consist of a back-to-back centrifugal compressor and radial inflow turbine supported on gas bearings with a design rotating speed of 1.2 Mrpm. This design speed is many times the natural frequency of the radial bearing system. Primarily due to the exacting requirements of the micron scale bearings...

Design of Si/SiC hybrid structures for elevated temperature micro-turbomachinery

Moon, Hyung-Soo, 1969-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 229 leaves; 11574627 bytes; 11574337 bytes; application/pdf; application/pdf
ENG
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thermal softening behavior at temperatures above 900 K. This thermal softening behavior limits the turbine inlet temperature, which in turn significantly degrades the overall engine efficiency. Previous studies have shown that hybrid structures of silicon and silicon carbide have good potential for improved engine performance. Detailed design of Si/SiC hybrid structures for high temperature micro-turbomachinery, however, has been hampered by the relatively poor performance of single crystal Si at elevated temperatures and high stresses and by the unavailability of accurate material properties data for both Si and SiC at the temperatures of interest. From previous work, the critical structures and materials issues to be resolved, in order to proceed with the design of high temperature Si/SiC hybrid structures, were identified as follows: 1. the safety margin of the Si/SiC hybrid structures based on the upper yield strength of Si 2. reliable estimation of the service life of the Si/SiC hybrid structures 3. structural instabilities caused by the combination of stress concentrations and strain softening. In the course of this thesis, these issues provided the key motivations of the work, and have been substantially resolved. As a first step...

Vibration detection in turbomachinery using non-contacting sensors

Cohen, Eric D., M. Eng. Massachusetts Institute of Technology
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 105 p.
ENG
Relevância na Pesquisa
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Recent developments have seen the introduction of multiple Eddy Current Sensors (ECS) into turbomachinery. These sensors employ an active magnetic field to monitor each blade as it passes the sensor. They generate an electrical signal proportional to the distance of a blade from the sensor. Existing algorithms extract two pieces of information from the ECS signature, signal magnitude and signal zero crossing time. The signal magnitude is used to find tip clearance, and the zero crossing time is used to estimate vibrational parameters over the course of multiple revolutions. These techniques fail to exploit the majority of the information contained in the ECS signal. In this research, a novel residue characterization algorithm was developed that processes the full ECS pulse to produce a residue. The residue is a speed independent representation of differences between a baseline ECS pulse and an experimental ECS pulse. A mathematical model of the relationship between blade displacement and residue was developed. Empirical data collected with the MIT spin pit were used to verify convergence of the model with the residue characterization algorithm. This strongly suggests blade vibration can be deduced using the residue characterization method with a single ECS sensor.; by Eric D. Cohen.; Thesis (M. Eng.)--Massachusetts Institute of Technology...

Novel turbomachinery concepts for highly integrated airframe/propulsion systems

Shah, Parthiv N
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 260 p.
ENG
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Two novel turbomachinery concepts are presented as enablers to advanced flight missions requiring integrated airframe/propulsion systems. The first concept is motivated by thermal management challenges in low-to-high Mach number (4+) aircraft. The idea of compressor cooling combines the compressor and heat exchanger function to stretch turbopropulsion system operational limits. Axial compressor performance with blade passage heat extraction is assessed with computational experiments and meanline modeling. A cooled multistage compressor with adiabatic design point is found to achieve higher pressure ratio, choking mass flow, and efficiency (referenced to an adiabatic, reversible process) at fixed corrected speed, with greatest benefit occurring through front-stage cooling. Heat removal equal to one percent of inlet stagnation enthalpy flux in each of the first four blade rows suggests pressure ratio, efficiency, and choked flow improvements of 23%, 12%, and 5% relative to a baseline, eight-stage compressor with pressure ratio of 5. Cooling is also found to unchoke rear stages at low corrected speed. Heat transfer estimations indicate that surface area limitations and temperature differences favor rear-stage cooling and suggest the existence of an optimal cooling distribution.; (cont.) The second concept is a quiet drag device to enable slow and steep approach profiles for functionally quiet civil aircraft. Deployment of such devices in clean airframe configuration reduces aircraft source noise and noise propagation to the ground. The generation of swirling outflow from a duct...

Characterization and design of non-adiabatic micro-compressor impeller and preliminary design of self-sustained micro engine system

Sirakov, Borislav Todorov, 1975-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 129 p.
ENG
Relevância na Pesquisa
17.54%
As part of the MIT research program on micro-engines (of size [approximately] 1 cm), this thesis defines concepts and designs to improve micro-turbomachinery and overall system performance. Three-dimensional Reynolds-averaged Navier-Stokes computations (FLUENT) have been carried out to quantify the performance limiting processes in micro-impellers. These processes include (i) heat transfer to the compressor flow responsible for up to 25 points efficiency penalty, (ii) impeller casing drag (17 points penalty) and (iii) passage boundary layer loss (10 points penalty). The magnitude of the first effect is a result of the engine small length scale selection and is characterized by the total heat to impeller flow as fraction of inlet flow enthalpy. The magnitudes of the last two effects can be attributed to low Reynolds number. Scaling laws for elucidating the parametric controlling trend in these effects have been formulated. A mean-line analysis and design tool based on the above micro-impeller characterization is developed to formulate design guidelines. The guidelines show that the optimal micro-impeller geometry changes with impeller wall temperature, an effect, not present for large turbomachinery. In particular, impeller inlet angle...

Development of a MEMS-Scale Turbomachinery Based Vacuum Pump

Shea, Michael J.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
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This study forms part of a larger study to develop a MEMS scale turbomachinery based vacuum pump. This would allow very high vacuum to be drawn for handheld mass spectroscopy. This thesis concentrates on the roughing portion of the turbo pump where flow can still be treated as a continuum but the no slip boundary condition is not accurate. The first portion of this thesis investigates flow at Knudsen numbers ranging from 0.001 to 0.1. By using a first order analysis, the wall shear stress can be specified in a commercial computational fluid dynamics code allowing slip flow to occur. This method was validated against a basic Poiseuille flow at these higher Knudsen numbers where slip flow was present. This demonstrated that it was possible to use a commercial code to model Knudsen number flows between 0.001 to 0.1. The second part of the thesis focused on the design of a roughing pump stage consisting of three blade rows a stationary inlet and outlet surrounding the rotor blade row. The no slip condition was not imposed as the simulated stage was assumed to be the outlet stage, and thus operating at a very low Knudsen number. A two dimensional analysis was developed to define the initial blade shape to achieve a maximum pressure ratio. A three dimensional simulation was developed to investigate the effects of tip leakage losses. The simulations are able to predict pressure ratio and power consumption of a particular stage of a MEMS scale turbopump. The final predicted pressure ratio of a stage with tip clearance is 1.0722 with power consumption of 0.4648 watts.

A computer program for the installation of blading in a turbomachinery rotor resulting in minimum unbalance

Yardimoglu, Ali Riza
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
Relevância na Pesquisa
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Approved for public release, distribution unlimited; The assembly of blades of different masses in a turbomachinery rotor may result in an unbalanced force acting on the rotor during rotation. There is a blade sequence for which a minimum imbalance exists. In this thesis, an algorithm was devised and a computer program was written to determine the sequence for minimum imbalance.

Design of shock-free transonic flow in turboomachinery

Sobieczky, Helmut
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Relatório Formato: v, 34 p. : ill. ; 28 cm.
EN_US
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A new design method for transonic flow in turbomachinery is described. The idea is based on the author's previous experience with hodograph methods but carried out in physical space. If combined with a flow analysis code the new method can be used as a design/analysis tool. Results illustrating this procedure are given for two dimensional flow through cascades and past airfoils. Existing configurations can be made shock-free by computational modifications which are limited to that portion of the design shape which is wetted by supersonic flow; Prepared for: Naval Air Systems Command, Code AIR-310, Washington, DC 20360.; http://archive.org/details/designofshockfre00sobi; financial support provided by the Naval Air Systems Command, Code AIR-310, under Work Order No. 57236; NA

A multidisciplinary algorithm for the 3-D design optimization of transonic axial compressor blades

Jones, James A.
Fonte: Monterey, California: Naval Postgraduate School Publicador: Monterey, California: Naval Postgraduate School
Formato: xviii, 164 p. : ill. (some col.) ; 28 cm.
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Approved for public release; distribution is unlimited; A new, multidisciplinary algorithm for the CFD design optimization of turbomachinery blades is presented. It departs from existing techniques in that it uses a simple, previously-developed Bezier geometry representation (BLADE-3D) that can be easily manipulated to achieve true 3-D changes in blade shape. The algorithm incorporates zero and first-order optimization techniques including sensitivity analyses and one-dimensional search methodology. It features an iterative finite element structural analysis as well as a cold shape correction procedure to ensure that the resulting blade meets steady-stress structural requirements. The process was applied to two different transonic fan designs - the Sanger rotor designed for the NPS Turbomachinery Laboratory and NASA Rotor 67, otherwise known as the 'NASA Fan'. The optimization objectives for the two designs were mass flow rate and polytropic efficiency respectively. Results for the Sanger rotor effort yielded an 8.1 % improvement in mass flow rate, a 5% improvement in total pressure ratio, and a 0.9 % increase in adiabatic efficiency. Application to the NASA Fan resulted in a 2.5 % increase in polytropic efficiency. The results validate the utility of the BLADE-3D Bezier geometry package for use in future development of automated optimization routines for turbomachinery blade design.; Commander...

Multiscale Finite Element Methods for turbulence modeling in turbomachinery CFD

Santoriello, Andrea
Fonte: La Sapienza Publicador: La Sapienza
Tipo: Tese de Doutorado
EN
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Giancarlo Chiatti, Vincenzo La Rocca, Giuseppe Vella

Design, analysis and optimization of the power conversion system for the Modular Pebble Bed Reactor System; Power conversion system for the MPBR

Wang, Chunyun, 1968-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 231 p.; 2757769 bytes; 4206218 bytes; application/pdf; application/pdf
ENG
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17.54%
The Modular Pebble Bed Reactor system (MPBR) requires a gas turbine cycle (Brayton cycle) as the power conversion system for it to achieve economic competitiveness as a GenIV nuclear system. The availability of controllable helium turbomachinery and compact heat exchangers are thus the critical enabling technology for the gas turbine cycle. The development of an initial reference design for an indirect helium cycle has been accomplished with the overriding constraint that this design could be built with existing technology and complies with all current codes and standards. Using the initial reference design, limiting features were identified. Finally, an optimized reference design was developed by identifying key advances in the technology that could reasonably be expected to be achieved with limited R&D. This final reference design is an indirect, intercooled and recuperated cycle consisting of a three-shaft arrangement for the turbomachinery system. A critical part of the design process involved the interaction between individual component design and overall plant performance. The helium cycle overall efficiency is significantly influenced by performance of individual components. Changes in the design of one component, a turbine for example...

MEMS turbomachinery rotordynamics : modeling, design and testing; Microelectromechanical systems turbomachinery rotordynamics : modeling, design and testing

Teo, Chiang Juay
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 350 p.
ENG
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27.54%
One of the major challenges encountered for the successful operation of high-power-density micro-devices lies in the stable operation of the bearings supporting the high-speed rotating machinery. This thesis presents the analysis, design, microfabrication, testing and operation of high speed micro-hydrostatic gas bearings for microturbomachinery in power-MEMS applications. A novel turbine driven microbearing test device for demonstrating repeatable high-speed gas bearing operation was designed, microfabricated and tested. The new microbearing test device incorporates numerous features, including a four plena journal bearing feed system enabling both isotropic and anisotropic journal bearing operation, labyrinth seals for reducing rotordynamic coupling, a redesigned turbine for satisfying power requirements, reinforced thrust bearing structural design, a novel rotor fabrication technology for achieving low radial imbalance and a symmetric feed system to avoid rotor sideloading arising from pressure or flow non-uniformities. A rigorous theory is presented to analyze the effects of compressibility in micro-flows (characterized by low Reynolds numbers and high Mach numbers) through hydrostatic thrust bearings for application to microturbomachines.; (cont.) Operating protocols for ensuring thrust bearing static stability have been established and successfully demonstrated on several micro-devices in the MIT Microengine Project. In addition...

Inflow turbulence generation for eddy-resolving simulations of turbomachinery flows

Arolla, Sunil K.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/08/2014
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A simple variant of recycling and rescaling method to generate inflow turbulence using unstructured grid CFD codes is presented. The method has been validated on large eddy simulation of spatially developing flat plate turbulent boundary layer. The proposed rescaling algorithm is based on the momentum thickness which is more robust and essentially obviates the need of finding the edge of the turbulent boundary layer in unstructured grid codes. Extension of this algorithm to hybrid RANS/LES type of approaches and for wall-bounded turbomachinery flows is also discussed. Results from annular diffuser with different inflow boundary layer characteristics is presented as an example application to show the utility of such an algorithm.; Comment: arXiv admin note: text overlap with arXiv:1408.1060

Density-Matching for Turbomachinery Optimization Under Uncertainty

Seshadri, Pranay; Parks, Geoffrey; Shahpar, Shahrokh
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 14/10/2015
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A monotonic, non-kernel density variant of the density-matching technique for optimization under uncertainty is developed. The approach is suited for turbomachinery problems which, by and large, tend to exhibit monotonic variations in the circumferentially and radially mass-averaged quantities--such as pressure ratio, efficiency and capacity--with common aleatory turbomachinery uncertainties. The method is successfully applied to de-sensitize the effect of an uncertainty in rear-seal leakage flows on the fan stage of a modern jet engine.; Comment: 9 pages

The Design of a Micro-turbogenerator

Camacho, Andrew Phillip
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Tese de Doutorado
Publicado em //2011
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17.74%

The basic scaling laws that govern both turbomachinery and permanent magnet generator power density are presented. It is shown for turbomachinery, that the power density scales indirectly proportional with the characteristic length of the system. For permanent magnet generators, power density is shown to be scale independent at a constant current density, but scale favorably in reality as a result of the scaling laws of heat dissipation.

The challenges that have affected micro-turbogenerators in the past are presented. Two of the most important challenges are the efficiency of micro-turbomachinery and the power transfer capabilities of micro-generators.

The basic operating principles of turbomachinery are developed with emphasis on the different mechanisms of energy transfer and how the ratio of these mechanisms in a turbine design relates to efficiency. Loss models are developed to quantify entropy creation from tip leakage, trailing edge mixing, and viscous boundary layers over the surface of the blades. The total entropy creation is related to lost work and turbine efficiency. An analysis is done to show turbine efficiency and power density as a function of system parameters such as stage count, RPM, reaction, and size. The practice of multi-staging is shown to not be as beneficial at small scales as it is for large scales. Single stage reaction turbines display the best efficiency and power density...

Flutter and Forced Response of Turbomachinery with Frequency Mistuning and Aerodynamic Asymmetry

Miyakozawa, Tomokazu
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação Formato: 5553163 bytes; application/pdf
Publicado em 25/04/2008 EN_US
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This dissertation provides numerical studies to improve bladed disk assembly design for preventing blade high cycle fatigue failures. The analyses are divided into two major subjects. For the first subject presented in Chapter 2, the mechanisms of transonic fan flutter for tuned systems are studied to improve the shortcoming of traditional method for modern fans using a 3D time-linearized Navier-Stokes solver. Steady and unsteady flow parameters including local work on the blade surfaces are investigated. It was found that global local work monotonically became more unstable on the pressure side due to the flow rollback effect. The local work on the suction side significantly varied due to nodal diameter and flow rollback effect. Thus, the total local work for the least stable mode is dominant by the suction side. Local work on the pressure side appears to be affected by the shock on the suction side. For the second subject presented in Chapter 3, sensitivity studies are conducted on flutter and forced response due to frequency mistuning and aerodynamic asymmetry using the single family of modes approach by assuming manufacturing tolerance. The unsteady aerodynamic forces are computed using CFD methods assuming aerodynamic symmetry. The aerodynamic asymmetry is applied by perturbing the influence coefficient matrix. These aerodynamic perturbations influence both stiffness and damping while traditional frequency mistuning analysis only perturbs the stiffness. Flutter results from random aerodynamic perturbations of all blades showed that manufacturing variations that effect blade unsteady aerodynamics may cause a stable...

Design for Coupled-Mode Flutter and Non-Synchronous Vibration in Turbomachinery

Clark, Stephen Thomas
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2013
Relevância na Pesquisa
37.96%

This research presents the detailed investigation of coupled-mode flutter and non-synchronous vibration in turbomachinery. Coupled-mode flutter and non-synchronous vibration are two aeromechanical challenges in designing turbomachinery that, when present, can cause engine blade failure. Regarding flutter, current industry design practices calculate the aerodynamic loads on a blade due to a single mode. In response to these design standards, a quasi three-dimensional, reduced-order modeling tool was developed for identifying the aeroelastic conditions that cause multi-mode flutter. This tool predicts the onset of coupled-mode flutter reasonable well for four different configurations, though certain parameters were tuned to agree with experimentation. Additionally, the results of this research indicate that mass ratio, frequency separation, and solidity have an effect on critical rotor speed for flutter. Higher mass-ratio blades require larger rotational velocities before they experience coupled-mode flutter. Similarly, increasing the frequency separation between modes and raising the solidity increases the critical rotor speed. Finally, and most importantly, design guidelines were generated for defining when a multi-mode flutter analysis is required in practical turbomachinery design.

Previous work has shown that industry computational fluid dynamics can approximately predict non-synchronous vibration (NSV)...