Dissertations / Theses on the topic 'Turbomachinery aerodynamics'
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Gostelow, J. P. "Publications in turbomachinery aerodynamics and related fields." Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384347.
Full textHe, Li. "Unsteady flows around oscillating turbomachinery blades." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385407.
Full textNing, Wei. "Computation of unsteady flow in turbomachinery." Thesis, Durham University, 1998. http://etheses.dur.ac.uk/4819/.
Full textMelzer, Andrew Philip. "Aerodynamics of transonic turbine trailing edges." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/276280.
Full textTsay, W. C. "The analysis and design methods for turbomachinery flows." Thesis, Cranfield University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233928.
Full textBrock, Jerry S. "A modified Baldwin-Lomax turbulence model for turbomachinery wakes." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-09052009-040231/.
Full textKnapke, Clint J. "Aerodynamics of Fan Blade Blending." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1567517259599736.
Full textForhad, Md Moinul Islam. "Robustness analysis for turbomachinery stall flutter." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4894.
Full textID: 030423207; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2011.; Includes bibliographical references (p. 44-47).
M.S.
Masters
Mechanical, Materials, and Aerospace Engineering
Engineering and Computer Science
Sharpe, Jacob Andrew. "3D CFD Investigation of Low Pressure Turbine Aerodynamics." Wright State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=wright1495872867696744.
Full textChernysheva, Olga V. "Flutter in sectored turbine vanes." Doctoral thesis, KTH, Energy Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3737.
Full textIn order to eliminate or reduce vibration problems inturbomachines without a high increase in the complexity of thevibratory behavior, the adjacent airfoils around the wheel areoften mechanically connected together with lacing wires, tip orpart-span shrouds in a number of identical sectors. Although anaerodynamic stabilizing effect of tying airfoils together ingroups on the whole cascade is indicated by numerical andexperimental studies, for some operating conditions suchsectored vane cascade can still remain unstable.
The goal of the present work is to investigate thepossibilities of a sectored vane cascade to undergoself-excited vibrations or flutter. The presented method forpredicting the aerodynamic response of a sectored vane cascadeis based on the aerodynamic work influence coefficientrepresentation of freestanding blade cascade. The sectored vaneanalysis assumes that the vibration frequency is the same forall blades in the sectored vane, while the vibration amplitudesand mode shapes can be different for each individual blade inthe sector. Additionally, the vibration frequency as well asthe amplitudes and mode shapes are supposed to be known.
The aerodynamic analysis of freestanding blade cascade isperformed with twodimensional inviscid linearized flow model.As far as feasible the study is supported by non-linear flowmodel analysis as well as by performing comparisons againstavailable experimental data in order to minimize theuncertainties of the numerical modeling on the physicalconclusions of the study.
As has been shown for the freestanding low-pressure turbineblade, the blade mode shape gives an important contributioninto the aerodynamic stability of the cascade. During thepreliminary design, it has been recommended to take intoaccount the mode shape as well rather than only reducedfrequency. In the present work further investigation using foursignificantly different turbine geometries makes these findingsmore general, independent from the low-pressure turbine bladegeometry. The investigation also continues towards a sectoredvane cascade. A parametrical analysis summarizing the effect ofthe reduced frequency and real sector mode shape is carried outfor a low-pressure sectored vane cascade for differentvibration amplitude distributions between the airfoils in thesector as well as different numbers of the airfoils in thesector. Critical (towards flutter) reduced frequency maps areprovided for torsion- and bending-dominated sectored vane modeshapes. Utilizing such maps at the early design stages helps toimprove the aerodynamic stability of low-pressure sectoredvanes.
A special emphasis in the present work is put on theimportance for the chosen unsteady inviscid flow model to bewell-posed during numerical calculations. The necessity for thecorrect simulation of the far-field boundary conditions indefining the stability margin of the blade rows isdemonstrated. Existing and new-developed boundary conditionsare described. It is shown that the result of numerical flowcalculations is dependent more on the quality of boundaryconditions, and less on the physical extension of thecomputational domain. Keywords: Turbomachinery, Aerodynamics,Unsteady CFD, Design, Flutter, Low-Pressure Turbine, Blade ModeShape, Critical Reduced Frequency, Sectored Vane Mode Shape,Vibration Amplitude Distribution, Far-field 2D Non-ReflectingBoundary Conditions. omain.
Keywords:Turbomachinery, Aerodynamics, Unsteady CFD,Design, Flutter, Low-Pressure Turbine, Blade Mode Shape,Critical Reduced Frequency, Sectored Vane Mode Shape, VibrationAmplitude Distribution, Far-field 2D Non-Reflecting BoundaryConditions.
Heinlein, Gregory S. "Aerodynamic Behavior of Axial Flow Turbomachinery Operating in Transient Transonic Flow Regimes." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1573149943024303.
Full textKurtulus, Berkin. "Development of a Tool for Inverse Aerodynamic Design and Optimisation of Turbomachinery Aerofoils." Thesis, KTH, Flygdynamik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-293353.
Full textAutomatisering av processen för design av vingprofiler kräver fortlöpande insatser inom området turbomaskindesign, med stort fokus på att utveckla nya tillförlitliga och konsekventa metoder som kan tillgodose ingenjörernas behov. Ett stort antal olika tillvägagångssätt har provats för omvänd design av vingprofiler såsom teoretisk invers design, statistiska metoder, empiriska upptäckter och många andra sätt att lösa designproblemet. Detta avhandlingsarbete är också ett lyckat försök att utveckla ett verktyg i Python som ska användas i den aerodynamiska designprocessen; det är enkelt, snabbt och noggrant för den initiala designen av turbomaskinblad med fokus på turbinblad som för användning i flygmotorer. För att förmedla beslutsprocessen under utvecklingen presenteras ett förenklat fall. De underliggande övervägandena diskuteras. Andra tillgängliga metoder i litteraturen som används för liknande problem utvärderas och jämförs för att visa fördelarna och begränsningarna med de metoder som används i verktyget. Det omvända designproblemet formuleras som ett multi-objektivt optimeringsproblem för att hantera olika mål som är relevanta för aerodynamisk design av turbomaskiner. Testkörningar görs och resultaten diskuteras för att bedöma hur robust verktyget är och hur de nuvarande funktionerna kan modifieras eller utökas. Efter utvecklingsprocessen verifieras verktyget som ett lämpligt alternativ för verkliga designoptimeringsuppgifter och kan användas som en byggsten för ett mycket mer omfattande verktyg som kan utvecklas i framtiden.
Sheard, A. G. "Aerodynamic and mechanical performance of a high-pressure turbine stage in a transient wind tunnel." Thesis, University of Oxford, 1989. http://ora.ox.ac.uk/objects/uuid:73ecb15e-efde-474d-ae30-3f8f7e1d6f4e.
Full textFlegel, Ashlie Brynn. "Aerodynamic Measurements of a Variable-Speed Power-Turbine Blade Section in a Transonic Turbine Cascade." Cleveland State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=csu1387437733.
Full textDiPietro, Anthony Louis. "Design and experimental evaluation of a dynamic thermal distortion generator for turbomachinery research." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-09292009-020206/.
Full textZhang, Luying. "Rotating instability on steam turbine blades at part-load conditions." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:cf8ecad1-0fd2-49b7-8e28-6d00c62c173e.
Full textWilde, Daniel G. "Validation of a CFD Approach for Gas Turbine Internal Cooling Passage Heat Transfer Prediction." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1384.
Full textFawcett, Richard James. "Coherent unsteadiness in film cooling." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:57ec3da6-4946-4f66-8421-b01d53d7e0fc.
Full textTang, Brian M. T. "Unshrouded turbine blade tip heat transfer and film cooling." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:f8479e89-9cd1-4aa7-b5c8-8068ad80de54.
Full textSanz, Luengo Antonio. "Experimental Investigation of the Influence of Local Flow Features on the Aerodynamic Damping of an Oscillating Blade Row." Licentiate thesis, KTH, Kraft- och värmeteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145179.
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Saroch, Michael F. (Michael Frank) Carleton University Dissertation Engineering Mechanical and Aerospace. "Contributions to the study of turbomachinery aerodynamics; Part I: Design of a fish-tail diffuser test section, Part II: Computations of the effects of AVDR on transonic turbine cascades." Ottawa, 1996.
Find full textJöcker, Markus. "Numerical Investigation of the Aerodynamic Vibration Excitation of High-Pressure Turbine Rotors." Doctoral thesis, KTH, Energy Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3416.
Full textThe design parameters axial gap and stator count of highpressure turbine stages are evaluated numerically towards theirinfluence on the unsteady aerodynamic excitation of rotorblades. Of particular interest is if and how unsteadyaerodynamic considerations in the design could reduce the riskofhigh cycle fatigue (HCF) failures of the turbine rotor.
A well-documented 2D/Q3D non-linear unsteady code (UNSFLO)is chosen to perform the stage flow analyses. The evaluatedresults are interpreted as aerodynamic excitation mechanisms onstream sheets neglecting 3D effects. Mesh studies andvalidations against measurements and 3D computations provideconfidence in the unsteady results. Three test cases areanalysed. First, a typical aero-engine high pressure turbinestage is studied at subsonic and transonic flow conditions,with four axial gaps (37% - 52% of cax,rotor) and two statorconfigurations (43 and 70 NGV). Operating conditions areaccording to the resonant conditions of the blades used inaccompanied experiments. Second, a subsonic high pressureturbine intended to drive the turbopump of a rocket engine isinvestigated. Four axial gap variations (10% - 29% ofcax,rotor) and three stator geometry variations are analysed toextend and generalise the findings made on the first study.Third, a transonic low pressure turbine rotor, known as theInternational Standard Configuration 11, has been modelled tocompute the unsteady flow due to blade vibration and comparedto available experimental data.
Excitation mechanisms due to shock, potential waves andwakes are described and related to the work found in the openliterature. The strength of shock excitation leads to increasedpressure excitation levels by a factor 2 to 3 compared tosubsonic cases. Potential excitations are of a typical wavetype in all cases, differences in the propagation direction ofthe waves and the wave reflection pattern in the rotor passagelead to modifications in the time and space resolved unsteadypressures on the blade surface. The significant influence ofoperating conditions, axial gap and stator size on the wavepropagation is discussed on chosen cases. The wake influence onthe rotorblade unsteady pressure is small in the presentevaluations, which is explicitly demonstrated on the turbopumpturbine by a parametric study of wake and potentialexcitations. A reduction in stator size (towards R≈1)reduces the potential excitation part so that wake andpotential excitation approach in their magnitude.
Potentials to reduce the risk of HCF excitation in transonicflow are the decrease of stator exit Mach number and themodification of temporal relations between shock and potentialexcitation events. A similar temporal tuning of wake excitationto shock excitation appears not efficient because of the smallwake excitation contribution. The increase of axial gap doesnot necessarily decrease the shock excitation strength neitherdoes the decrease of vane size because the shock excitation mayremain strong even behind a smaller stator. The evaluation ofthe aerodynamic excitation towards a HCF risk reduction shouldonly be done with regard to the excited mode shape, asdemonstrated with parametric studies of the mode shapeinfluence on excitability.
Keywords:Aeroelasticity, Aerodynamics, Stator-RotorInteraction, Excitation Mechanism, Unsteady Flow Computation,Forced Response, High Cycle Fatigue, Turbomachinery,Gas-Turbine, High-Pressure Turbine, Turbopump, CFD, Design
Newman, Timothy James. "Towards a silent fan : an investigation of low-speed fan aeroacoustics." Thesis, University of Cambridge, 2015. https://www.repository.cam.ac.uk/handle/1810/251318.
Full textAhmadi, Majid. "Aerodynamic inverse design of transonic turbomachinery cascades." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0003/NQ40321.pdf.
Full textChoi, Myeonggeun. "Thermal control of gas turbine casings for improved tip clearance." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:14a9ce6a-2af6-4187-afe7-8c6f8e113855.
Full textSy, Birame. "Adaptabilité en espace d'un schéma volumes finis d'ordre élevé pour la CFD/CAA des turbomachines." Thesis, Paris, HESAM, 2020. http://www.theses.fr/2020HESAE045.
Full textIn the digital age, almost all of a product’s development cycle is done on a computer. There is no longer a need to physically produce drafts. Their characteristics can be tested with precision that depends on the maturity of the simulation methods. Researchers in digital simulation therefore have the challenge of transferring their recent advances to industry. In fluid mechanics, the computer codes must gain in adaptability in order to take into account the morphology of the problem and the mesh.The configuration of advanced methods should be delegated by the non-expert user to the machine.This research work focused on the adaptability in space of a high order finite volume scheme (FV-MLS). The high order is an essential element in order to capture highly unsteady phenomena. To increase the order of precision, the FV-MLS scheme involves a high order polynomial reconstruction by Least Mobile Squares. MLS has great potential in terms of flexibility for handling complex geometries. It also has a large number of parameters that can be integrated into an optimization process.This work first provided answers concerning the sensitivity of the method regarding the MLS parameters. At a second level, a series of algorithms for the relevant choice of these parameters has been developed, while clearly improving the robustness, the precision and the calculation efficiency. The user’s load has therefore been reduced significantly, allowing him to focus on his core business. This methodology has been validated up to order 6. To improve the robustness of the numerical scheme vis-à-vis the anisotropy of the mesh, a new high-order local reconstruction framework has been defined. This local reconstruction makes it possible to reduce or even annihilate the effects of anisotropy. Several validation cases and examples of applications have been carried out in order to demonstrate the value of the proposed methods
Wang, Dingxi. "Turbomachinery aerodynamic and aeromechanic design optimization using the adjoint method." Thesis, Durham University, 2008. http://etheses.dur.ac.uk/2057/.
Full textRamer, Becky E. (Becky Ellen). "Aerodynamic response of turbomachinery blade rows to convecting density distortions." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/49964.
Full textWijesinghe, Hettithanthrige Sanith 1974. "Aerodynamic response of turbomachinery blade rows to convecting density wakes." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/50476.
Full textIncludes bibliographical references (p. 129-131).
Density wakes have been recently identified as a possible new source for high cycle fatigue failure in the compressor blades of modern turbomachinery. In order to characterize the density wake induced force and moment fluctuations in compressor blades a two-dimensional computational study has been conducted in viscous compressible flows with Mach numbers ranging from M[infinity], = 0.15 to M[infinity] = 0.87 and flow Reynolds number Re(c, U[infinity]) ~~700,000. Parametric tests were conducted at each flow Mach number to establish trends for the change in the maximum fluctuation of the blade force and moment coefficients with the changes in the density wake width 0.1 < w/c < 1.0 and the density ratio 0.25 < P2/P1 < 2.0. Results indicate the magnitude of the blade force and moment fluctuations to scale with (1) the non-dimensional density wake width w/c, (2) a non-dimensional density parameter p* and (3) flow Mach number M[infinity]. The viscous flow simulations have also indicated (1) periodic vortex shedding at the blade trailing edge and (2) separation bubbles on the blade suction surface which generate additional force and moment fluctuations with amplitudes ±(10 - 100%) about the time averaged mean values. These flow features represent possible additional sources for high cycle fatigue failure. Simple functional relationships have also been derived at each flow Mach number to quantify the force and moment fluctuations described above. In addition a simple cascade flow model has been developed in conjunction with the computational study to help determine the trends in the force and moment fluctuations with varying density wake properties and compressor geometries.
by Hettithanthrige Sanith Wijesinghe.
S.M.
Coppinger, Miles. "Aerodynamic performance of an industrial centrifugal compressor variable inlet guide vane system." Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/7263.
Full textWillcox, Karen E. (Karen Elizabeth). "Reduced-order aerodynamic models for aeroelastic control of turbomachines." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9265.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 138-143).
Aeroelasticity is a critical consideration in the design of gas turbine engines, both for stability and forced response. Current aeroelastic models cannot provide high-fidelity aerodynamics in a form suitable for design or control applications. In this thesis low-order, high-fidelity aerodynamic models are developed using systematic model order reduction from computational fluid dynamic (CFD) methods. Reduction techniques are presented which use the proper orthogonal decomposition, and also a new approach for turbomachinery which is based on computing Arnoldi vectors. This method matches the input/output characteristic of the CFD model and includes the proper orthogonal decomposition as a special case. Here, reduction is applied to the linearized two-dimensional Euler equations, although the methodology applies to any linearized CFD model. Both methods make efficient use of linearity to compute the reduced-order basis on a single blade passage. The reduced-order models themselves are developed in the time domain for the full blade row and cast in state-space form. This makes the model appropriate for control applications and also facilitates coupling to other engine components. Moreover, because the full blade row is considered, the models can be applied to problems which lack cyclic symmetry. Although most aeroelastic analyses assume each blade to be identical, in practice variations in blade shape and structural properties exist due to manufacturing limitations and engine wear. These blade to blade variations, known as mistuning, have been shown to have a significant effect on compressor aeroelastic properties. A reduced-order aerodynamic model is developed for a twenty-blade transonic rotor operating in unsteady plunging motion, and coupled to a simple typical section structural model. Stability and forced response of the rotor to an inlet ow disturbance are computed and compared to results obtained using a constant coefficient model similar to those currently used in practice. Mistuning of this rotor and its effect on aeroelastic response is also considered. The simple models are found to inaccurately predict important aeroelastic results, while the relevant dynamics can be accurately captured by the reduced-order models with less than two hundred aerodynamic states. Models are also developed for a low-speed compressor stage in a stator/rotor configuration. The stator is shown to have a significant destabilizing effect on the aeroelastic system, and the results suggest that analysis of the rotor as an isolated blade row may provide inaccurate predictions.
by Karen Elizabeth Willcox.
Ph.D.
Fruth, Florian. "Reduction of Aerodynamic Forcing inTransonic Turbomachinery : Numerical Studies on Forcing Reduction Techniques." Doctoral thesis, KTH, Kraft- och värmeteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-127967.
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Watson, Brian Christopher. "An investigation into the influence of mistuning on the forced response of bladed disk assemblies." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/12463.
Full textPayer, Florent. "Prédiction et analyse du phénomène de réponse forcée : application à un cas de compresseur haute pression." Phd thesis, Ecole Centrale de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-01063776.
Full textBrouckaert, Jean-François M. "Development of fast response aerodynamic probes for time-resolved measurements in turbomachines." Doctoral thesis, Universite Libre de Bruxelles, 2002. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211406.
Full textMorris, Mary Beth. "Flow randomness and tip losses in transonic rotors." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-07212009-040241/.
Full textMonaco, Lucio. "PARAMETRIC STUDY OF THE EFFECT OF BLADE SHAPE ON THE PERFORMANCE OF TURBOMACHINERY CASCADES : PART III A: AERODYNAMIC DAMPING BEHAVIOUR – COMPRESSOR PROFILES." Thesis, KTH, Kraft- och värmeteknologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-131210.
Full textGhate, Devendra. "Inexpensive uncertainty analysis for CFD applications." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:6be44a1d-6e2f-4bf9-b1e5-1468f92e21e3.
Full textNuckolls, William E. "Fan noise reduction from a supersonic inlet." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-08222009-040447/.
Full textPowers, Laura M. "Computer-aided design of axial-flow fans." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/91059.
Full textM.S.
Lewis, Daniel Joseph. "Tip clearance and angle of attack effects upon the unsteady response of a vibrating flat plate in crossflow /." This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06112009-063924/.
Full textUgolotti, Matteo. "Implementation and Evaluation of Machine Learning Assisted Adjoint Sensitivities Applied to Turbomachinery Design Optimization." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1593267985073912.
Full textButler, Bradley D. "AXIAL COMPRESSOR FLOW BEHAVIOR NEAR THE AERODYNAMIC STABILITY LIMIT." UKnowledge, 2014. http://uknowledge.uky.edu/me_etds/34.
Full textFletcher, Nathan James. "Design and Implementation of Periodic Unsteadiness Generator for Turbine Secondary Flow Studies." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1560810428267352.
Full textKumar, Sandeep. "Non-AXisymmetric Aerodynamic Design-Optimization System with Application for Distortion Tolerant Hybrid Propulsion." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613749886763596.
Full textO'Dowd, Devin Owen. "Aero-thermal performance of transonic high-pressure turbine blade tips." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:e7b8e7d0-4973-4757-b4df-415723e7562f.
Full textCeylanoglu, Arda. "An Accelerated Aerodynamic Optimization Approach For A Small Turbojet Engine Centrifugal Compressor." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12611371/index.pdf.
Full textStein, Alexander. "Computational analysis of stall and separation control in centrifugal compressors." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/11884.
Full textGreen, Brian Richard. "Time-Averaged and Time-Accurate Aerodynamic Effects of Rotor Purge Flow for a Modern, Rotating, High-Pressure Turbine Stage and Low-Pressure Turbine Vane." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1322535026.
Full textGougeon, Pierre. "Interactions aérodynamiques entre une turbine haute pression et le premier distributeur basse pression." Thesis, Ecully, Ecole centrale de Lyon, 2014. http://www.theses.fr/2014ECDL0026/document.
Full textImproving the performance of current aeronautical turbines is an important issue in a context of severe economical and environmental constraints. In a turbofan, the inter-turbine channel which is located between the High-Pressure (HP) turbine and the first Low Pressure (LP) vane is characterized by a complex flow. Therefore aerodynamic structures coming from the HP turbine (wakes, vortices and showkwaves) strongly interact between each other and affect the LP vane flow field. This generates efficiency losses of the overall configuration. This PhD thesis aims at studying the aerodynamic phenomena between a HP turbine and the first LP vane and at analyzing the mechanisms creating aerodynamic losses. A previous experimental campaign, which was carried out on a facility including a HP turbine coupled to a LP vane, enabled to gather flow field measurements in planes located in the inter-turbine channel and downstream of the LP vane. In comparison with these experimental data, the numerical simulations done with elsA software intend to reproduce accurately the 3D, unsteady and turbulent nature of the flow within this configuration. The work can be divided into three mains steps. As a first step, steady simulations with a sliding mesh treatment enable to understand the general aspects of the flow. An assessment of the effects of RANS (Reynolds-Averaged Navier-Stokes) turbulent predictions and of spatial numerical schemes on the aerodynamic structures present in the configuration is carried out. As a second step, the advanced turbulence approach ZDES (Zonal Detached-Eddy Simulation) is considered for the LP vane flow prediction. The unsteady aerodynamic structures coming from the upstream HP rotor are set as an inlet boundary condition of the computational domain. The ZDES approach is compared to a URANS (Unsteady RANS) approach on the same computational domain. The generation and dissipation of the wakes and vortices are significantly different on the two simulations, and thus impact the creation of aerodynamic losses. Finally, URANS simulations enable to better understand the interaction effects between the different blade rows. First, the unsteady phase-lagged approaches that take into account a single rotor and stator assess the important unsteady effects in the inter-turbine channel. They finally lead to the implementation of a multipassages phase-lagged computation that takes into account the two stators and the rotor in order to model all the existing determinist interactions. In order to quantify them accurately, a modal decomposition of the unsteady flow field is set up. The interaction levels linked to the different blade rows are therefore quantified and the impact of the aerodynamic losses is evaluated