| Performance Limiting Flow Processes in High-State Loading High-Mach Number Compressors |
13 MAR 2008 |
67 pages |
| Authors:
Choon S. Tan; MASSACHUSETTS INST OF TECH CAMBRIDGE GAS TURBINE LAB
|
 | In high-stage loading high-Mach number (HLM) compressors, counter-rotating pairs of discrete vortices are shed at the trailing edge of the upstream blade row at a frequency corresponding to the downstream rotor blade passing frequency. This is a consequence of an alternating change in blade loading caused by the passage of shocks or compression waves emanating from the downstream rotor. While this effect is present at any Mach number the combination ... |
|
| Nondestructive Evaluation Technology Initiatives II. Delivery Order 0002: Whole Field Turbine Disk Inspection |
APR 2007 |
314 pages |
| Authors:
Donna J. Mayton; SCIENCE APPLICATIONS INTERNATIONAL CORP SAN DIEGO CA
|
| This program sought to characterize and optimize the Sonic IR inspection technique for the inspection of Air Force aircraft components through empirical methods. As part of that effort, TF33 second stage turbine blades, F100 first stage high pressure turbine disks, various compressor blades, landing gear components, and a vane ring were inspected. Elongated scallop samples and fluorescent penetrant inspection (FPI) probability of detection (PoD) samples with known flaws were also ... |
|
| Increased Range/Mini-Cruise Missile |
21 MAR 2006 |
2 pages |
| Authors:
NATIONAL CENTER FOR DEFENSE MANUFACTURING AND MACHINING LATROBE PA
|
| Technical Directions Inc. (TDI), Ortonville, Michigan, was asked by the U.S. Army and the U.S. Air Force to improve the efficiency of their J-45 missile engine for the NLOS-LS LAM Loitering Attack Missile. The ultimate goal is to improve the overall engine efficiency by 8 percent, thereby reducing fuel consumption for the propulsion system, allowing for both increased vehicle payload and/or increased vehicle range. The newly designed compressor wheel requires ... |
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| Impact of Leading-Edge Orientation and Shape on Performance of Compressor Blades |
JUN 2005 |
95 pages |
| Authors:
Jonathan D. Powell; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis presents a Computation Fluid Dynamics (CFD) analysis of the aerodynamic performance of circular and elliptical leading edges of compressor blades, with a range of leading edge droop angles. Specifically, simulations were conducted, with a free stream Mach number of 0.65 to quantify the change in pressure distributions and boundary layer momentum thickness in the leading-edge region for a range of incidences on a flat plate with various leading-edge ... |
|
| HCF Performance and FOD Tolerance Improvement in Ti-6AI-4V Vanes With LPB Treatment |
JAN 2004 |
10 pages |
| Authors:
Paul S. Prevey; N. Jayaraman; Ravi A. Ravindranath; LAMBDA RESEARCH CINCINNATI OH
|
| Mechanical surface treatments that introduce a layer of residual surface compression improve high cycle fatigue (HCF) performance. If the depth of compression extends through the thickness of blade or vane edges, foreign object damage (FOD) tolerance can be dramatically improved. The effect of low plasticity burnishing (LPB) on the HCF performance and FOD tolerance of a first stage Ti-6Al-4V turbine engine vane have been investigated in both tension-tension (R=0.1) and ... |
|
| iMAST Quarterly, Number 1, 2004 |
Jan-2004 |
9 pages |
| Authors:
APPLIED RESEARCH LABORATORY STATE COLLEGE PA
|
| This quarterly briefly addresses engine fretting evaluation. The feature article is titled Light Armored Vehicle Noise Control. Exploiting the acoustics expertise resident at ARL Penn State, engineers were asked by the Marine Corps to address noise issues related to the Light Armored Vehicle. The integration of advanced materials, manufacturing processes, health monitoring, and acoustic tailoring promotes reductions in gross weight, vibration, interior noise, and life-cycle cost, as well as increases ... |
|
| An Assessment of Laboratory Techniques for Simulating Foreign Object Damage on a Leading Edge Geometry |
MAY 2003 |
6 pages |
| Authors:
Steven R. Thompson; John J. Ruschau; Theodore Nicholas; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| Foreign object damage (FOD) from particles ingested into jet engines can have a detrimental effect on the fatigue strength of fan and compressor airfoils. The damage caused by these particles often is in the form of a geometric discontinuity like a notch. However the presence of residual stresses and substructural damage in regions adjacent to the notch prohibit the use of simple notch analyses. In this investigation, three different (quasi-static, ... |
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| Design of Aspirated Compressor Blades Using Three-Dimensional Inverse Method |
APR 2003 |
18 pages |
| Authors:
T. Q. Dang; M. Van Rooij; L. M. Larosiliere; ARMY RESEARCH LAB CLEVELAND OH*
|
| A three-dimensional viscous inverse method is extended to allow blading design with full interaction between the prescribed pressure-loading distribution and a specified transpiration scheme. Transpiration on blade surfaces and endwalls is implemented as inflow/outflow boundary conditions, and the basic modifications to the method are outlined. This paper focuses on a discussion concerning an application of the method to the design and analysis of a supersonic rotor with aspiration. Results show ... |
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| Experimental Investigation of Vortex Shedding in High Reynolds Number Flow Over Compressor Blades in Cascade |
MAR 2003 |
|
| Authors:
Choon P. Lim; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
 | An investigation of vortex shedding downstream of a cascade of compressor stator blades, at off-design inlet-flow angles of 35, 33 and 31 degrees and Reynolds numbers, based on chord length, of 625,000, 750,000 and 800,000 is reported. The objective of the study was to characterize the flow and vortex shedding through blade surface pressure measurements and hot-wire anemometry. Vortex shedding was determined to be a leading edge phenomenon as periodic ... |
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| Preliminary Design Code for an Axial Stage Compressor |
SEP 2001 |
136 pages |
| Authors:
Rizwan R. Ramakdawala; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Current two dimensional preliminary design codes use structured programming, which is rigid and does not allow the user to vary parameters easily. This study uses object-oriented programming to allow the user to vary all selectable parameters in a familiar Windows operating environment. The programmed design is based on the assumptions of axial and free-vortex flow between blade rows, simple radial equilibrium, and a thermally and calorically perfect gas. The program ... |
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| Micro Adaptive Flow Control |
SEP 2000 |
10 pages |
| Authors:
Richard Wlezien; DEFENSE ADVANCED RESEARCH PROJECTS AGENCY ARLINGTON VA
|
| The Defense Advanced Research Projects Agency (DARPA) Micro Adaptive Flow Control program is described using a series of illustrative examples. Adaptive flow control is defined to be the active modification of aerodynamic flows using small-time dependent actuators in judiciously chosen locations. A diverse number of large-scale applications are described in which micro adaptive flow control has a substantial overall system benefit. |
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| Implementation of a Two Probe Tip-Timing Technique to Determine Compressor Blade Vibrations |
JUN 2000 |
54 pages |
| Authors:
Nicholas G. Osburn; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This study involved the implementation and validation of a blade-tip time of arrival (TOA) measurement technique, and the development of a computer program to analyze TOA data using a recently published approach. The program was used to analyze experimental compressor data taken in-house using two laser light probes, data generated computation ally, and data obtained by others in a compressor test. The in-house compressor data was ... |
|
| A Statistical Analysis of Space Structure Mode Localization |
MAR 1999 |
270 pages |
| Authors:
Amy M. Cox; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
|
| Cyclic structures, such as antenna arrays, multi-bay trusses, and compressor blades, are significantly impacted by slight changes to system periodicity. Manufacturing errors of 5% or less can result in drastic changes to a structure's modal behavior. This change in modal behavior is significant, since it may result in the focusing of modal energy to individual substructures of the system. Poor modal identification can result in poorly designed control systems, resulting ... |
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| Application of a Modified Dynamic Compression System Model to a Low- Aspect-Ratio Fan: Effects of Inlet Distortion |
AUG 95 |
84 pages |
| Authors:
Kimball A. Shahrokhi; ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFS TN
|
| The objective of this research was to modify and calibrate a l-D dynamic compression system model, DYNTECC, to more accurately simulate compressor operation with steady, nonuniform inlet flow. The modifications were based upon parallel compressor theory, and modeled both circumferential and radial effects of distorted inlet flow. The modifications included circumferential and radial mass redistribution, dynamic blade response, and radial work redistribution. The circumferential mass redistribution allowed mass transport between ... |
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| Hotwire Measurements of the Turbulent Flow Into a Cascade of Controlled- Diffusion Compressor Blades |
DEC 93 |
64 pages |
| Authors:
Bryce E. Wakefield; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Turbulence measurements near the leading edge of a compressor stator were made in a subsonic cascade wind tunnel with a hotwire system. Using a single hot-film probe, velocity and turbulence distortion data were obtained about the leading edge of the Controlled-Diffusion (CD) blades in order to verify Laser Doppler Velocimetry (LDV) data taken in earlier studies. Measurements were conducted at a Mach number of .25, a Reynolds number of 711000 ... |
|
| Effects of Crenulations on Three Dimensional Losses in a Linear Compressor Cascade |
DEC 93 |
196 pages |
| Authors:
William L. Spacy Ii; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| An experimental investigation into the effect of compressor blade trailing edge geometry on three-dimensional flows in a linear cascade was conducted at the AFIT linear cascade test facility. Hot-wire/hot-film anemometry along with total pressure instrumentation was used to analyze crenulation generated vortices and their interaction with the three-dimensional flows in the cascade. The effects of this interaction on the performance parameters associated with the cascade were quantified. The results-indicate that ... |
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| Real-Time Parameter Identification Applied to Flight Simulation. |
APR 1993 |
|
| Authors:
L. A. Pineiro; D. J. Biezad; AERONAUTICAL SYSTEMS CENTER WRIGHT-PATTERSON AFB OH
|
| In-flight simulations are normally accomplished using model-following control laws which depend on accurate knowledge of the stability derivatives of the host aircraft. Degraded simulation results if the stability derivatives deviate considerably from their presumed values. Gain scheduling is often employed to compensate for plant parameter variations, but this form of open-loop compensation usually requires extensive flight testing for proper fine tuning. An adaptive, fast-sampling control law to compensate for changing ... |
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| Flow Phenomena in Turbomachines |
20 JAN 93 |
181 pages |
| Authors:
E. M. Creitzer; A. H. Epstein; M. B. Giles; J. E. McCune; C. S. Tan; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF AERONAUTICS AND ASTRONAUTICS
|
| This report describes work carried out at the Gas Turbine Laboratory at MIT during the period 10/20/89 - 10/19/92, as part of our multi-investigator effort on basic unsteady flow phenomena in turbomachines. Within the overall project four separate tasks are specified. These are. in brief: (1) The Influence of Inlet Temperature Nonuniformities on Turbine Heat Transfer and Dynamics; (2) Assessment of Unsteady Losses in Stator/ Rotor Interactions; (3) Unsteady Phenomena ... |
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| Model Fan Passage Flow Simulation |
DEC 92 |
|
| Authors:
David D. Myre; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Two-dimensional experimental and numerical simulations of a transonic fan blade passage were conducted at a Mach number of 1.4 to provide baseline data for the study of the effects of vortex generating devices on the suction surface shock-boundary layer interaction. In the experimental program, a probe and traverse system were designed and constructed. A new data acquisition system was adapted to record data from probe measurements and multiple scans of ... |
|
| Integrated Blade Inspection System (IBIS) Upgrade Study |
DEC 92 |
294 pages |
| Authors:
Tony J. DeLiberato; Steven W. Perkins; Steven K. Saplin; John G. Snyder; Gregory J. Toussaint; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| The purpose of this design study was to identify ways to improve the Integrated Blade Inspection System. The Air Force requires inspection of jet engine compressor and turbine blades to locate defects and prevent engine failure. The current inspection process uses fluorescent penetrant as an aid to identify cracked blades. A systems engineering design process was applied to evaluate the current inspection techniques and to develop alternative methods to satisfy ... |
|
| Viscous Design and Analysis Methods for Transonic Compressor Blading |
13 FEB 91 |
167 pages |
| Authors:
Mark Drela; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF AERONAUTICS AND ASTRONAUTICS
|
| A viscous/inviscid computational method for the design and analysis of quasi-3D cascades has been developed. The specific application targeted is supersonic compressor blading with splitter blades, although the method is applicable to any type of cascade. The method is an extension of the ISES viscous/inviscid methodology. A streamline-based inviscid Euler formulation is fully coupled to an integral boundary layer formulation to describe the overall viscous flowfield. Rotation and streamtube contraction ... |
|
| Empirical Flutter Prediction Method |
05 MAR 88 |
|
| Authors:
J. K. Casey; GE AIRCRAFT ENGINES CINCINNATI OH ADVANCED TECHNOLOGY OPERATION
|
| Design of advanced technology engines is often limited by compressor blade instability or flutter. Test points from the annular cascade data base were analyzed, to predict from aeromechanical data which of 14 types of stability or instability would result. The basic approach was to identify for each pair of stability regions, linear combinations (hyperplanes) of the aeromechanical variables, whose numerical value would be above a critical level for all test ... |
|
| Operation of Gas Turbine Engines in Dust-Laden Environments, |
SEP 1987 |
|
| Authors:
M. G. Dunn; C. Padova; R. M. Adams; CALSPAN ADVANCED TECHNOLOGY CENTER BUFFALO NY
|
| Results are reported for a measurement program designed to investigate the performance deterioration of gas turbine engines and the associated auxiliary equipment difficulties when operating in dust-laden environments. Three TF33 turbofan engines and one J57 turbojet engine have been tested with two different dust blends. The predominant damage mechanism in all of the engines was compressor blade erosion. The length of dust exposure time required to cause engine damage was ... |
|
| Investigation of Dihedral Effects in Compressor Cascades, |
SEP 1987 |
|
| Authors:
F. A. Breugelmans; VON KARMAN INST FOR FLUID DYNAMICS RHODE-SAINT-GENESE (BELGIUM)
|
| An experimental investigation of the influence of blade dihedral on the secondary flow in a two dimensional NASA 65-series compressor cascade is performed. Different inlet boundary layer thicknesses are used on the endwalls. Three different stacking lines have been chosen, namely a straight line inclined at 15, 25 and 35, a circular arc and an elliptic arc. The incidence range up to stall has been investigated and the local beneficial ... |
|
| The Unsteady Flow in the Far Field of an Isolated Blade Row |
APR 87 |
|
| Authors:
Joseph M. Verdon; UNITED TECHNOLOGIES RESEARCH CENTER EAST HARTFORD CT
|
| This report describes a theoretical investigation of the unsteady flow in the far field of an isolated two-dimensional blade row. In particular, analytic far-field solutions are derived for cascades operating at subsonic, transonic and supersonic inlet and exit Mach numbers. These solutions describe the velocity potential fluctuations associated with irrotational pressure (acoustic) disturbances, rotational velocity disturbances and the vorticity shed form blade trailing edges and convected along blade wakes. As ... |
|
| Transmission of Inlet Distortion through a Fan, |
MAR 1987 |
11 pages |
| Authors:
J. E. Flitcroft; J. Dunham; W. A. Abbott; ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH (ENGLAND)
|
| The effect of inlet swirl on the propagation of total pressure distortion through a 3-stage fan without inlet guide vanes has been investigated on a compressor rig. The tests gave the unexpected finding that the presence of a swirl counter to the rotation of the fan generally reduced the level of steady state distortion transmitted to the core compressor. Dynamic pressure measurements made at the exit from the fan, however, ... |
|
| A Quasi Three Dimensional Method for the Calculation of Transonic Flows in Turbomachines, |
MAR 1987 |
|
| Authors:
Joerg Haller; STUTTGART UNIV (GERMANY F R) INST FUER LUFTFAHRT-ANTRIEBE
|
| A procedure based on the iterative coupling of flow calculations on S1 blade-to-blade stream surfaces and a flow calculation on an S2 hub to tip stream surface is described. The solutions on S1 surfaces of revolution are obtained by a time marching method in finite volume form, whereas a finite difference method is used for the S2 calculation. The finite difference method uses a stream function formulation based on a ... |
|
| Computation of Transonic 2D Cascade Flow and Comparison with Experiments, |
MAR 1987 |
|
| Authors:
H. W. Happel; H. J. Dietrichs; K. Lehmann; MOTOREN- UND TURBINEN-UNION G M B H MUNICH (GERMANY F R)
|
| This paper describes a time-marching finite area method to obtain the steady 2D blade to blade solution along an axisymmetric stream surface with changing radius and stream tube thickness. The conservation laws are solved in a rotating frame. The numerical scheme is explicit and first order accurate in time and space. To achieve stability, explicit numerical viscosity is added. Three alternative methods of ensuring the zero normal velocity condition along ... |
|
| A Numerical Study of Unsteady Flow Effects in a Supersonic Compressor Cascade, |
MAR 1987 |
|
| Authors:
Scott M. Richardson; AIR FORCE WRIGHT AERONAUTICAL LABS WRIGHT-PATTERSON AFB OH
|
| Recent experimental evidence exists which suggests that compressor cascades operating supersonically may pass a higher mass flow with a periodic inflow condition than with the thermodynamically equivalent mass-averaged steady condition. Since most compressor design methods rely on the use of an axi-symmetric analysis, any excursion in mass flow caused by blade row interactions will not be accounted for in the design. In the present study the two-dimensional Navier-Stokes equations are ... |
|
| Transonic Compressor Blade Tip Flow Visualization on a Water Table |
DEC 86 |
|
| Authors:
Alan K. Byrd; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The shock structure at the tip of a transonic compressor rotor was investigated on a water table. A four bladed cascade model was used and the wave pattern was examined at variable incidence, flow turning angles and back- pressures. Froude numbers, (equivalent to Mach numbers in the analogous two dimensional gas flow), in the range 1.6 to 1.74 resulted in an oblique shock between the blade passages starting from the ... |
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| Preliminary Investigation of the Use of Holographic Interferometry to Detect Ill-Fitting Compressor Blades |
NOV 86 |
|
| Authors:
S. J. Rumble; B. Lawrie; AERONAUTICAL RESEARCH LABS MELBOURNE (AUSTRALIA)
|
| The technique of double exposure holographic interferometry has been used to detect and investigate ill-fitting compressor blades. A brief introduction to holographic interferometry is given. Holographic interferometry has enabled the observation of the displacements of blades when the blades are subjected to a small force. The potential of a pulsed laser holographic system to be used for in-situ investigations is discussed. Keywords: Holographic interferometry Nondestructive testing; Gas turbine engines. (Australia) ... |
|
| Vibration Analysis by Speckle Interferometry, |
NOV 1986 |
|
| Authors:
Hartwig Knoell; MOTOREN- UND TURBINEN-UNION G M B H MUNICH (GERMANY F R)
|
| The vibrational modes of complex systems can be visualized with high sensitivity by laser light speckle interferometry. Electronic speckle pattern interferometry (ESPI), in contrast to holography, does not use photo-chemical storage media but shows a live image of the vibrational modes created by the time-average method directly on a monitor screen. The particular advantage of this very useful and now almost conventional procedure of vibration analysis is demonstrated by two ... |
|
| Advanced Instrumentation for Aero Engine Components: Conference Proceedings of the Propulsion and Energetics Panel Symposium (67th) Held in Philadelphia, Pennsylvania on 19-23 May 1986 |
NOV 86 |
|
| Authors:
ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT NEUILLY-SUR-SEINE (FRANCE)
|
| This Conference Proceedings contains 35 papers. The Symposium was arranged in the following sessions: Coherent Anti-Stokes Raman Spectroscopy (5); Laser Anemomentry (10); Pyrometry (3); High Speed Data Acquisition and Processing (6); Vibration, Thin Layer and Tip Clearance Measurements (6); and Future Prospects (5). The technical evaluation reports, separately prepared for each session, are included in the conference proceedings. Questions and answers follow each paper, and a Round Table Discussion follows ... |
|
| Hostile Atmospheric Environment Effects on Jet Engines |
06 SEP 85 |
|
| Authors:
W. Tabakoff; A. Hamed; CINCINNATI UNIV OH
|
| Aircraft engines operating in areas where the atmosphere is polluted by small solid particles are typical examples of jet engines operating under hostile atmospheric environment. The particles may be different kinds of sand, volcanic ashes or others. Under these conditions, the gas and particles experience different degrees of turning as they flow through the engine. This is mainly due to the difference in their inertia. This paper presents the results ... |
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| Analysis of the Effects of Transient Heat Transfer on Axial Flow Compressor Blade Boundary Layers |
JUN 85 |
|
| Authors:
C. W. Wood; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| This thesis determines the magnitude of heat transfer in the high- pressure compressor of a turbofan engine during a 'Bodie' throttle transient and estimates the effect of transient heat transfer on compressor blade boundary layer growth. Total stored thermal energy available for release is determined considering compressor blades and roots only. Thermal energy released during a throttle transient is determined and allocated to individual compressor stages and used to estimate ... |
|
| Proceedings of the Army Science Conference (14th) Held at the United States Military Academy, West Point, New York on 19-21 June 1984. Volume 3. Principal Authors P through Z |
22 JUN 1984 |
|
| Authors:
DEPUTY CHIEF OF STAFF FOR RESEARCH DEVELOPMENT AND ACQUISITION (ARMY) WASHINGTON D C
|
| These Proceedings of the 1984 Army Science Conference are a compilation of all papers presented at the conference and the supplemental papers that were submitted. Papers included in this volume follow: A New Multifunction Acousto-Optic Signal Processor; Evaluation and Interpretation of Compressor Intra-Blade Flow Field Measurements Obtained Using an Advanced Laser Anemometer System; Universal Lithium Batteries; A Momentum Analyzer for Intense Relativistic Electron Beams; Nonlinear Optical Properties of Selected Organic ... |
|
| Report of Tests of a Compressor Configuration of CD (Controlled Diffusion) Blading |
MAR 1984 |
|
| Authors:
Y. Koyuncu; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Results of 14 tests in a subsonic cascade are reported in which the air inlet angle and Reynolds number were varied. The cascade contained 20 Controlled Diffusion (CD) blades, with 5.01 inches chord, aspect ratio of 2.0 and solidity of 1.67. Pneumatic probe surveys and surface pressure measurements were used to obtain blade performance and flow quality data. There was no measurable influence of the Reynolds number on the blade ... |
|
| Impact Composite Blade. |
17 JAN 1984 |
|
| Authors:
R. G. Carlson; DEPARTMENT OF THE AIR FORCE WASHINGTON DC
|
| The top portion of a composite (boron filament/aluminum matrix) blade which is useable in a fluid flow machine is made more resistant to impact energy by forming a cavity in the boron filament layer of the tip portion of each laminate (or ply) of the blade, then filling each cavity with a resin, and then bonding together the laminates with the resin-filled cavities therein. (Author) |
|
| Problems Associated with Particulate Flow in Turbomachinery |
1984 |
|
| Authors:
W. Tabakoff; A. Hamed; CINCINNATI UNIV OH DEPT OF AEROSPACE ENGINEERING AND APPLIED MECHANICS
|
|
| Some Structural Features of Unsteady Separating Turbulent Shear Flows, |
1984 |
|
| Authors:
R. L. Simpson; SOUTHERN METHODIST UNIV DALLAS TX
|
| Some physical features of unsteady separating turbulent boundary layers are presented for practical Reynolds numbers and reduced frequencies for helicopter and turbomachinery flows. Upstream of detachment in moderate amplitude flows, the flow is quasi-steady i.e., the phase-averaged flow is described by the steady free-stream flow structure. Results show that oscillation waveform and amplitude strongly influence the detached flow behavior. |
|
| The Conjoint Action of High and Low Cycle Fatigue |
NOV 1983 |
|
| Authors:
B. E. Powell; I. Henderson; PORTSMOUTH POLYTECHNIC (ENGLAND) MECHANICAL BEHAVIOUR OF MATERIALS LAB
|
| Fatigue crack propagation rates in Ti-6Al-4V subjected to relatively high frequency low amplitude vibrations superimposed on higher amplitude low frequency major cycles are studied. It is concluded that the vibrations, or minor cycles, have negligible effect below their fatigue threshold value. Above this level the minor cycles will contribute to the total growth rate; their contribution, successfully predicted by the method of linear summation, is dependent on their relative number ... |
|
| Roughness Effects on Compressor Blade Performance in Cascade at High Reynolds Number |
NOV 1983 |
|
| Authors:
F. J. Tanis Jr; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| An experimental investigation of the effect of roughness on compressor blade performance in cascade at high Reynolds numbers was performed. A 7-blade cascade of NACA 64-A905 blades with a chord of 2 in. and aspect ratio of 1 was tested in linear cascade. The blades were mounted with a stagger angle of 31 deg and angle of attack of 15 deg. Spacing between blades was 1.33 in. which gave a ... |
|
| Proceedings of the Conference on Viscous Effects in Turbomachines Held at Copenhagen, Denmark on 1-3 June 1983 |
SEP 1983 |
|
| Authors:
ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT NEUILLY-SUR-SEINE (FRANCE)
|
| Five reports, in French, not individually analyzed discuss the following topics: Computation of Viscous Inviscid Interaction; Coupling Methods for Inverse Calculation of transonic Internal Flow with Shock Wave; Experimental Methods of Analyzing Shock-Boundary Layer Interactions; Computation of Three Dimensional Boundary Layer In a Compressor; and Studies of Viscous Wall Layers in a One Stage Transonic Axial Flow Compressor. (Author) |
|
| Compressor and Turbine Blade Boundary Layer Separation, |
SEP 1983 |
|
| Authors:
M. J. Werle; UNITED TECHNOLOGIES RESEARCH CENTER EAST HARTFORD CT
|
| Numerous sites on compressor and turbine blades are susceptible to the phenomenon of boundary layer separation. In such situations it is found that the boundary layer is incapable of negotiating a local adverse pressure gradient, which is subsequently relieved as it breaks away from the surface and induces a strong interaction with the inviscid stream. Since losses and heating due to such occurrences can be significant, a need continues to ... |
|
| Annulus Wall Boundary Layer Development in a Compressor Stage Including the Effects of Tip Clearance, |
Sep-1983 |
|
| Authors:
B Lakshminarayana; K N S Murthy; M Pouagare; T R Govindan; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF AEROSPACE ENGINEERING
|
| The end-wall boundary layer development in a compressor stage, including the inlet guide vane (IGV) passage and the rotor passage, was measured. Measurements upstream of the rotor and inside the IGV passage were carried out with a five-hole probe. The data (blade-to-blade) inside the rotor passage were measured using a three-sensor rotating hot-wire below the tip clearance region and a 'V' configuration probe inside the clearance region. Rotor exit measurements ... |
|
| Experimental Verification of an Endwall Boundary Layer Prediction Method, |
Sep-1983 |
|
| Authors:
C W Elrod; J L Bettner; AIR FORCE WRIGHT AERONAUTICAL LABS WRIGHT-PATTERSON AFB OH
|
| An endwall boundary layer code was verified in a low speed compressor facility and used to compute casing blockage and efficiency penalty in a full-scale engine. Detailed endwall boundary layer measurements and overall compressor performance measurements were obtained for various conditions of surface roughness, porosity and tip clearance in the low speed compressor facility. Stage pressure ratio and stall margin were determined for the single-stage compressor at three corrected speeds. ... |
|
| Computer Program for Evaluating the Ives Transformation in Turbomachinery Cascades. Revision |
JUL 1983 |
|
| Authors:
W. J. Rae; CALSPAN ADVANCED TECHNOLOGY CENTER BUFFALO NY
|
| This report contains the description of a computer program for evaluating the Ives transformation, which maps a cascade of turbine or compressor blades conformally into a rectangle. (Author) |
|
| Research on Aero-Thermodynamic Distortion Induced Structural Dynamic Response of Multi-Stage Compressor Blading |
JUN 1983 |
|
| Authors:
Sanford Fleeter; PURDUE UNIV LAFAYETTE IN SCHOOL OF MECHANICAL ENGINEERING
|
| The overall objective of this research is to quantitatively investigate the fundamental phenomena relevant to aerothermodynamic distortion- induced structural dynamic blade response in multi-stage gas turbine fans and compressors. Unique unsteady aerodynamic data will be obtained to validate and indicate necessary refinements to state-of-the-art analyses and to direct the modeling of new analyses. Also, for the first time, a first principles capability to predict the vibrational response amplitude of blading ... |
|
| Effect of Sand Erosion on the Performance Deterioration of a Single Stage Axial Flow Compressor |
1983 |
|
| Authors:
W. Tabakoff; C. Balan; CINCINNATI UNIV OH
|
|
| Experimental Study on the Effects of Specimen Sizes on Erosion |
1983 |
|
| Authors:
W. Tabakoff; CINCINNATI UNIV OH DEPT OF AEROSPACE ENGINEERING AND APPLIED MECHANICS
|
|
Reports by Keyword(s)
COMPRESSOR BLADES
