Log in

Relevant bibliographies by topics / Laser Doppler velocimeter. Modal analysis

Contents

Journal articles
Dissertations / Theses
Books
Book chapters
Conference papers

Academic literature on the topic 'Laser Doppler velocimeter. Modal analysis'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Laser Doppler velocimeter. Modal analysis.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Laser Doppler velocimeter. Modal analysis"

1

Arruda, J. R. F. "Spatial Domain Modal Analysis of Lightly-Damped Structures Using Laser Velocimeters." Journal of Vibration and Acoustics 115, no. 3 (July 1, 1993): 225–31. http://dx.doi.org/10.1115/1.2930337.

Full text

Abstract:

Traditional modal identification techniques do not take advantage of the high spatial density of scanning Laser Doppler Velocimeter (LDV) measurements. In this paper, a spatial modal parameter estimation technique, specially adapted for use with LDV measurements, is presented. It is based on a real-mode modal filtering concept and, therefore, is applicable to structures with low damping. From the estimated mode shape surfaces, curve-fitted with two-dimensional Fourier series, angular displacements are calculated. A rectangular plate example illustrates the proposed techniques with both numerically simulated and experimental results.

APA, Harvard, Vancouver, ISO, and other styles

2

Lucas, M., and A. C. Smith. "Redesign of Ultrasonic Block Horns for Improved Vibration Performance." Journal of Vibration and Acoustics 119, no. 3 (July 1, 1997): 410–14. http://dx.doi.org/10.1115/1.2889739.

Full text

Abstract:

Ultrasonic block horns are prone to reliability problems associated with modal activity close to the tuned operating frequency. This paper presents an approach to block horn design, which relies on two laser based vibration measurement techniques, electronic speckle pattern interferometry (ESPI) and laser doppler velocimetry (LDV) modal analysis, to validate finite element (FE) models. Block horn vibration characteristics are interpreted from experimental and theoretical data such that successful horn redesign can be achieved from modifications to the FE models.

APA, Harvard, Vancouver, ISO, and other styles

3

Kalybek, Maksat, Mateusz Bocian, and Nikolaos Nikitas. "Performance of Optical Structural Vibration Monitoring Systems in Experimental Modal Analysis." Sensors 21, no. 4 (February 10, 2021): 1239. http://dx.doi.org/10.3390/s21041239.

Full text

Abstract:

Image-based optical vibration measurement is an attractive alternative to the conventional measurement of structural dynamics predominantly relying on accelerometry. Although various optical vibration monitoring systems are now readily available, their performance is currently not well defined, especially in the context of experimental modal analysis. To this end, this study provides some of the first evidence of the capability of optical vibration monitoring systems in modal identification using input–output measurements. A comparative study is conducted on a scaled model of a 3D building frame set in a laboratory environment. The dynamic response of the model to an impulse excitation from an instrumented hammer, and an initial displacement, is measured by means of five optical motion capture systems. These include commercial and open-source systems based on laser Doppler velocimetry, fiducial markers and marker-less pattern recognition. The performance of these systems is analysed against the data obtained with a set of high-precision accelerometers. It is shown that the modal parameters identified from each system are not always equivalent, and that each system has limitations inherent to its design. Informed by these findings, a guidance for the deployment of the considered optical motion capture systems is given, aiding in their choice and implementation for structural vibration monitoring.

APA, Harvard, Vancouver, ISO, and other styles

4

Filonovich, M. S., R. Azevedo, L. R. Rojas-Solórzano, and J. B. Leal. "Credibility analysis of computational fluid dynamic simulations for compound channel flow." Journal of Hydroinformatics 15, no. 3 (February 18, 2013): 926–38. http://dx.doi.org/10.2166/hydro.2013.187.

Full text

Abstract:

In this paper, verification and validation of a turbulence closure model is performed for an experimental compound channel flow, where the velocity and turbulent fields were measured by a Laser Doppler Velocimeter (LDV). Detailed Explicit Algebraic Reynolds Stress Model (EARSM) simulations are reported. There are numerous methods and techniques available to evaluate the numerical uncertainty associated with grid resolution. The authors have adopted the Grid Convergence Index (GCI) approach. The velocity components, the turbulence kinetic energy (TKE), the dissipation rate and the Reynolds stresses were used as variables of interest. The GCI results present low values for the u velocity component, but higher values in what concerns the v velocity component and w velocity component (representing secondary flows) and for Reynolds stresses RSxy and RSyz. This indicates that the mean flow has converged but the turbulent field and secondary flows still depend on grid resolution. Based on GCI values distribution, the medium and fine meshes were further refined. In addition to GCI analysis, the authors have performed linear regression analysis for estimating the mesh quality in what concerns small value variables. Comparison of numerical and experimental results shows good agreement.

APA, Harvard, Vancouver, ISO, and other styles

5

Ribando, R. J., J. L. Palmer, and J. E. Scott. "Flow in a partially filled, rotating, tapered cylinder." Journal of Fluid Mechanics 203 (June 1989): 541–55. http://dx.doi.org/10.1017/s0022112089001588.

Full text

Abstract:

The secondary flow patterns induced by a differentially rotating lid in a partially filled, rapidly rotating, tapered cylinder have been investigated. Using a new laser-Doppler velocimeter system capable of making measurements in the rotor frame of reference, the radial dependence of the azimuthal and axial velocity components was measured at two axial positions in the rotor. A linear, asymptotic analysis and a finite-difference simulation were made for comparison. The latter was performed on a boundary-fitted computational mesh so that the slanted rotor wall and the sagging free surface could be accommodated in the model. The agreement between the experimental and numerical results was excellent for the azimuthal velocity component and good for the axial component. Of particular interest is the modified E½ boundary layer on the slanted wall, a feature which is not present with a vertical sidewall.

APA, Harvard, Vancouver, ISO, and other styles

6

Jiang, Hongxu, Yalin Li, Yongwei Liu, and Dejiang Shang. "The system design for calibrating acoustic Doppler current meter in the laboratory." MATEC Web of Conferences 283 (2019): 08001. http://dx.doi.org/10.1051/matecconf/201928308001.

Full text

Abstract:

The Acoustic Doppler Current meter is a most commonly device for the velocity measurement of the seawater in the ocean. We had designed an equipment to calibrate the Acoustic Doppler Current meter in the laboratory, which is mainly composed of a vertical circulating water tank and a system of Laser Doppler Velocimetry. The vertical circulating water tank is the key device of the calibration equipment. The optimization of flow field is carried out by the software, CFD. The optimization of structure intensity, modal analysis and low noise is carried out by the software, ANSYS. We had also used the propeller map to design the power section of the water tank. Through the comparison of the velocity of the flow between Acoustic Doppler Current meter and LDV at the same position in the working section of the water tank, the former can be calibrated, because the wavelength of optics is much less than that of acoustics in the water. After the experimental test, we found that when the fluid flows in the vertical circulating water tank, there exists no resonance phenomenon and the velocity of the flow in the working section is approximately proportional to the rotation speed of the propeller.

APA, Harvard, Vancouver, ISO, and other styles

7

Geremew, Africa M., and Ernest K. Yanful. "Role of fines on cohesive behavior of mine tailings inferred from critical shear stress." Canadian Geotechnical Journal 48, no. 4 (April 2011): 568–82. http://dx.doi.org/10.1139/t10-089.

Full text

Abstract:

The significance of fines on the cohesive behavior of mine tailings has been investigated by examining the incipient motion of the tailings. Sixteen laboratory experiments were performed in a Plexiglas laboratory annular column on re-constituted mine tailings under a 50 cm water cover. Re-suspension was produced by a Teflon stirrer and the velocity field in the column was characterized using a laser Doppler velocimeter (LDV). The pressure change in the boundary layer was also measured with a Preston tube. It was observed that the nondimensional critical shear stresses showed deviation from those of the noncohesive model results at a fines content greater than 50%–55%. An empirical relation that shows the relation between the boundary shear stress deviation and the percent fines in the tailings was proposed. Regression analysis of the experimental results showed that a power law relationship could reasonably be used to describe the relation between the measured nondimensional excess bed shear stress and the erosion rate. It is proposed that the value of β (the erosion rate constant) could be taken as 1 for mine tailings that show cohesive behavior.

APA, Harvard, Vancouver, ISO, and other styles

8

Zhou Jian, 周健, 冯庆奇 Feng Qingqi, 马曙光 Ma Shuguang, 宋锐 Song Rui, 魏国 Wei Guo, and 龙兴武 Long Xingwu. "Error analysis of reference-beam laser Doppler velocimeter." High Power Laser and Particle Beams 22, no. 11 (2010): 2581–87. http://dx.doi.org/10.3788/hplpb20102211.2581.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Ilic, Jelena, Slavica Ristic, and Milesa Sreckovic. "Laser doppler velocimetry and confined flows." Thermal Science 21, suppl. 3 (2017): 825–36. http://dx.doi.org/10.2298/tsci160720278i.

Full text

Abstract:

Finding the mode, in which two component laser Doppler velocimetry can be applied to flows confined in cylindrical tubes or vessels, was the aim of this study. We have identified principle issues that influence the propagation of laser beams in laser Doppler velocimetry system, applied to flow confined in cylindrical tube. Among them, the most important are influences of fluid and wall refractive indices, wall thickness and internal radius ratio and beam intersection angle. In analysis of the degrees of these influences, we have applied mathematical model, based on geometrical optics. The separation of measurement volumes, that measure different velocity components, has been recognized as the main drawback. To overcome this, we propose a lens with dual focal length ? primary focal length for the measurement of one velocity component and secondary focal length for the measurement of the other velocity component. We present here the procedure for calculating the optimal value of secondary focal length, depending on experimental set-up parameters. The mathematical simulation of the application of the dual focal length lens, for chosen cases presented here, confirmed the accuracy of the proposed procedure.

APA, Harvard, Vancouver, ISO, and other styles

10

Liu Zijun, 刘子君, 崔骊水 Cui Lishui, and 谢代梁 Xie Dailiang. "Theory Analysis and Measurement for Interference Fringes of Laser Doppler Velocimeter." Chinese Journal of Lasers 44, no. 8 (2017): 0804001. http://dx.doi.org/10.3788/cjl201744.0804001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

More sources

Dissertations / Theses on the topic "Laser Doppler velocimeter. Modal analysis"

1

Li, Xinzuo William. "A precision laser scanning system for experimental modal analysis : its test and calibration /." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-08222009-040335/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Kil, Hyun-Gwon. "An automated scanning laser doppler system for vibration measurements and wave-vector analysis of vibration of shells." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/16856.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Yang, Ming. "Development and analysis of a multiple beam laser system for measurement of surface vibrations." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/17685.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Haber, Ludwig Christian. "Investigation of Dynamics in Turbulent Swirling Flows Aided by Linear Stability Analysis." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/11076.

Full text

Abstract:

Turbulent swirling flows are important in many applications including gas turbines, furnaces and cyclone dust separators among others. Although the mean flow fields have been relatively well studied, a complete understanding of the flow field including its dynamics has not been achieved. The work contained in this dissertation attempts to shed further light on the behavior of turbulent swirling flows, especially focused on the dynamic behavior of a turbulent swirling flow encountering a sudden expansion. Experiments were performed in a new isothermal turbulent swirling flow test facility. Two geometrical nozzle configurations were studied. The \cb\ nozzle configuration exhibits a cylindrical \cb\ in the center of the nozzle. The free vortex nozzle configuration is obtained when the cylindrical \cb\ is removed. Detailed laser velocimeter measurements were performed to map out the flow field near the sudden expansion of the 2.9" (ID) nozzle leading to the 7.4" (ID) downstream section. In addition to presenting detailed flow profiles for both nozzle and downstream flow fields, representative frequency spectra of the flow dynamics are presented. Along with the flow time histories and histograms, the wide variety of dynamic behavior was thus described in great detail. The dynamics observed in the experiment can be classified into three main categories: coherent and large scale motion, intermittent motion and coherent periodic motion. Free vortex geometry flows, in the parameter space of the experiments (Swirl number = 0 - 0.21), exhibited mostly coherent and large scale motion. The spectra in these cases were broadband with very light concentration of spectral energy observed in some specific cases. Center--body geometry flows exhibited all three categories of flows as swirl strength was increased from zero. Flows with little or no swirl exhibited broad--band spectra similar to those for the free vortex geometry. Intermediate swirl levels resulted in a large amount of low frequency energy which, with the aid of the time histories, was identified as a large scale intermittence associated with radial movement of the annular jet as it enters the sudden expansion. Large swirl levels resulted in high magnitude coherent oscillations concentrated largely just downstream of the sudden expansion. Linear stability analysis was used to help in the interpretation of the observed dynamics. Although, as implemented here (using the parallel flow assumption), the analysis was not successful in quantitatively matching the experimentally observed dynamics, significant insight into the physical mechanisms of the observed dynamics was obtained from the analysis. Specifically, the coherent oscillations observed for larger swirl levels were able to be described in terms of the interaction between the inner and outer shear layers of the flow field.
Ph. D.

APA, Harvard, Vancouver, ISO, and other styles

5

Braga, Carlos André da Silva Teles. "Caracterização de um ensaio de análise modal recorrendo a leitura sem contacto." Master's thesis, 2014. http://hdl.handle.net/1822/34352.

Full text

Abstract:

Dissertação de mestrado integrado em Engenharia Mecânica (área de especialização em Conceção de Estruturas)
Ao longo das últimas décadas, a preocupação com os efeitos das vibrações nos mais diversos tipos de estruturas tem vindo a aumentar. Ao longo deste tempo, para combater os efeitos indesejados das vibrações, tem sido desenvolvidos novos métodos e técnicas que ajudam a prever o comportamento dinâmico das estruturas, permitindo que se diminua os efeitos por estas causado. É neste contexto que se insere o desenvolvimento deste trabalho. Ao longo deste documento pretende-se desenvolver o estudo sobre um equipamento utilizado para a medição de vibrações, o vibrómetro laser. O objetivo deste trabalho foi realizar e caracterizar um ensaio experimental de análise modal com a utilização do vibrómetro laser. É também pretendido a exploração da funcionalidade diferencial do laser, a qual permite obter leituras diferencias entre dois objetos diferentes. Para tal utilizaram-se um conjunto de três placas metálicas, todas com características dinâmicas diferentes, essencialmente para validar a funcionalidade diferencial do laser. Inicialmente os três componentes foram analisados numericamente para posterior comparação com os resultados experimentais. Após a obtenção das soluções numéricas, realizaram-se ensaios experimentais para validar os resultados numéricos e assim avaliar as funcionalidades do equipamento laser. Para avaliar a funcionalidade diferencial do laser, os componentes foram montados uns nos outros e foram utilizadas várias variações no posicionamento dos sensores laser. Por fim, como os resultados não eram conclusivos, foram desenvolvidos novas metodologias utilizando excitadores eletrodinâmicos. A principal conclusão que se pode retirar da utilização do vibrómetro laser na medição de vibrações é que é um equipamento que permite a medição de vibrações de uma forma rápida e que, a sua utilização, não influência os dados obtidos pois é uma técnica não intrusiva. Em relação à funcionalidade diferencial não foi possível retirar nenhuma conclusão pois os dados obtidos da sua utilização não eram conclusivos.
Over the past decades the concern with vibration problems has increased. Throughout this time new methods have been developed to help in the prediction of the dynamic behaviour of structures and decreasing the effects caused by these. It is in this context that this presente work have been developed. Throughout this document is intended to develop the study of a equipment use for measuring mechanical vibrations, the LDV (Laser Doppler Vibrometer). The aim of this study was to characterize an modal analysis test using the LDV. It was also important exploit the differential feature of laser, which allows obtaining differential readings between two diferente objects. For this we used a set of three metal plates, each other with different dynamic characteristics, essentially to test the differential feature of LDV. Initially the three components were numerically analyzed to be compared with the experimental results. After obtaining the numerical solutions, were carried out experimental tests to validate the numerical results and thus evaluate the laser equipment features. To assess the differential functionality of the laser, the components were assembled each other and have been used many variations in the positioning of the laser sensor heads. As the results were not conclusive, it was necessary the development of new methodologies using electrodynamic shakers. The main conclusion that can be drawn from the use of LDV in vibration measurement is that the LDV allows measurement of vibration ina quick way and its use does not influence the data measured since it’s a non-intrusive technique. Regarding the differential function was not possible to draw any conclusions because the data obtained from it was not conclusive to evaluate it correctly.

APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Laser Doppler velocimeter. Modal analysis"

1

Leprince, F. Skin friction determination by LDV measurements in a viscous sublayer: Analysis of systematic errors. Rhode Saint Genese, Belgium: Von Karman Institute for Fluid Dynamics, 1985.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

2

United States. National Aeronautics and Space Administration., ed. Results from 1984 airborne Doppler lidar wind measurement program: Flight 6 : analysis of line-of-sight elevation angle errors and apparent Doppler velocities : interim report. Boulder, Colo: Universities Space Research Association, 1987.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

3

United States. National Aeronautics and Space Administration., ed. LV software support for supersonic flow analysis: Semiannual technical report, October 1991 to April 1992. [Washington, DC: National Aeronautics and Space Administration, 1992.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

4

United States. National Aeronautics and Space Administration., ed. LV software support for supersonic flow analysis: Semiannual technical report, October 1991 to April 1992. [Washington, DC: National Aeronautics and Space Administration, 1992.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

5

United States. National Aeronautics and Space Administration., ed. LV software support for supersonic flow analysis: Final technical report, October 1990 to October 1991. [Washington, DC: National Aeronautics and Space Administration, 1991.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

6

1928-, Dracos Th A., ed. Three-dimensional velocity and vorticity measuring and image analysis techniques: Lecture notes from the short course held in Zürich, Switzerland, 3-6 September 1996. Dordrecht: Kluwer Academic Publishers, 1996.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Laser Doppler velocimeter. Modal analysis"

1

Krüger, Jan, William Whelan-Curtin, Daniel Hoffmann, Rory Mullane, Alan P. O’Neill, and Peter O’Brien. "Semiconductor Laser Doppler Velocimeter for Micro-Fluidics Applications." In Micro Total Analysis Systems 2001, 351–52. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-010-1015-3_151.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Olvera, D., A. Elías-Zúñiga, M. Pineda, E. Macias, O. Martínez, L. N. López de Lacalle, and C. Rodríguez. "Identification of Stability Cutting Parameters Using Laser Doppler Vibrometry." In Topics in Modal Analysis, Volume 7, 553–60. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-6585-0_54.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Pesaresi, L., and C. W. Schwingshackl. "Automated Measurement Grid Generation for Scanning Laser Doppler Vibrometers." In Topics in Modal Analysis, Volume 7, 645–53. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-6585-0_62.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Castellini, P., P. Chiariotti, and M. Martarelli. "Mode Filtering of Continuous Scanning Laser Doppler Vibration Data." In Topics in Modal Analysis, Volume 7, 655–60. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-6585-0_63.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Fernandes, E. C., and M. V. Heitor. "On the Extension of a Laser-Doppler Velocimeter to the Analysis of Oscillating Flames." In Laser Techniques Applied to Fluid Mechanics, 383–401. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-56963-0_25.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Weekes, Ben, and David Ewins. "Effective Use of Scanning Laser Doppler Vibrometers for Modal Testing." In Topics in Modal Analysis II, Volume 8, 43–58. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-04774-4_5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Yang, Shifei, and Matthew S. Allen. "Transfer Functions to Measure Translational and Rotational Velocities with Continuous-Scan Laser Doppler Vibrometry." In Topics in Modal Analysis, Volume 7, 597–615. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-6585-0_58.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Ronkainen, Jouni, and Andy Harland. "Soccer Ball Modal Analysis Using a Scanning Laser Doppler Vibrometer (SLDV)." In The Engineering of Sport 6, 357–62. New York, NY: Springer New York, 2006. http://dx.doi.org/10.1007/978-0-387-46050-5_63.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Chiariotti, P., P. Castellini, and M. Martarelli. "Recovery of Mode Shapes from Continuous Scanning Laser Doppler Vibration Data: A Mode Matching Frequency Domain Approach." In Topics in Modal Analysis I, Volume 7, 207–13. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-04753-9_21.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Fischer, Andreas, Lars Büttner, Jürgen Czarske, Michael Eggert, and Harald Müller. "Array Doppler Global Velocimeter with Laser Frequency Modulation for Turbulent Flow Analysis – Sensor Investigation and Application." In Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 31–41. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-01106-1_4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Laser Doppler velocimeter. Modal analysis"

1

Alberga, D. G., G. E. Stephens, and B. V. Johnson. "Comparison of Predicted and Measured Velocities in a Compressor Disk Drum Model." In ASME 1987 International Gas Turbine Conference and Exhibition. American Society of Mechanical Engineers, 1987. http://dx.doi.org/10.1115/87-gt-208.

Full text

Abstract:

The tangential velocity distributions in the bleed and the trapped cavities of an eleven-cavity, compresor drum model were measured and predicted. The measurements were obtained with a Laser Doppler Velocimeter (LDV) in experiments using Freon-113 as the working fluid. The experiments were conducted at disk tangential Reynolds numbers of approximately 2 × 106 over a range of inward bleed flow rates through the center cavity. The experimental results show that the tangential velocity profiles in the bleed cavity vary from near-solid-body at low flow rates to near-free-vortex at the highest flow rate. The experimental results also showed a decrease in tangential velocity strength in the trapped flow cavities with distance from the bleed cavity. The flow in the bleed and trapped cavities were predicted using an analysis coupling the flow in a core region with the flow in the disk boundary layers. The secondary flow in the boundary layer was modeled using momentum integral equations. The core flow was determined by coupling the total flow with the boundary layer flow through the continuity equation, and the core tangential velocity was modeled with one dimensional viscous flow equations. Predicted results are presented for a range of flow conditions and cavity locations. The analytical model accurately predicted the tangential velocity distribution, and hence pressure drop, in both classes of cavities when the appropriate core turbulence model and boundary conditions were applied.

APA, Harvard, Vancouver, ISO, and other styles

2

Boccazzi, A., A. Perdichizzi, and U. Tabacco. "Flow Field Investigation in a Low Solidity Inducer by Laser Doppler Velocimeter." In ASME 1989 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1989. http://dx.doi.org/10.1115/89-gt-54.

Full text

Abstract:

The results of an experimental investigation of the flow-field within a low solidity inducer at design and off design flow rate are presented and discussed; particular attention is devoted to the analysis of the flow-field, at the tip in front of the leading edge, for the flow rate close to the back-flow onset. The flow-field was measured by means of a laser doppler velocimeter at four different axial positions: upstream, within and downstream of the inducer. Axial, tangential and relative flow angle distributions, in the measuring planes, are presented for three different flow coefficients. At the lower flow rate, the plots show the presence of reverse flow in the region close to the hub downstream of the trailing edge. For the same flow rate, quite low axial velocities are detected at the tip. This is in agreement with pressure probe traverses carried out in a slightly downstream section; these measurements also show radial inward velocities of the same order of magnitude as the axial velocities. Circumferentially averaged losses were evaluated from specific work and total head rise given by pressure probes.

APA, Harvard, Vancouver, ISO, and other styles

3

Turek, L. "An analysis of the flow behavior from a gas turbine combustor using a laser Doppler velocimeter." In 40th AIAA Aerospace Sciences Meeting & Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2002. http://dx.doi.org/10.2514/6.2002-13.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Khalil, Hossam, Dongkyu Kim, Joonsik Nam, and Kyihwan Park. "Modal analysis of rotating plate using tracking laser Doppler vibrometer: algorithm modification." In Fifth Asia Pacific Optical Sensors Conference, edited by Byoungho Lee, Sang-Bae Lee, and Yunjiang Rao. SPIE, 2015. http://dx.doi.org/10.1117/12.2184447.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Álvaro da Silva, Danilo, and Pablo Siqueira Meirelles. "Experimental modal analysis of electrical submersible pump using 3D scanning laser Doppler vibrometer." In DINAME2019. ABCM, 2019. http://dx.doi.org/10.26678/abcm.diname2019.din2019-0185.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Gamel, H., P. Salizzoni, L. Soulhac, P. Méjean, M. Marro, N. Grosjean, and B. Carissimo. "Turbulent Kinetic Energy Budget and Dissipation in the Wake of 2D Obstacle: Analysis of the K-ε Closure Model." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21489.

Full text

Abstract:

The prediction of the flow dynamics produced by the interaction between a sheared turbulent flow and a bluff body has important implications in the domain of the wind engineering and for what concerns the simulation of atmospheric dispersion of air-born pollutants. In this study we present the results of the experimental investigation on the wake of a 2D obstacle, immersed in a neutrally stratified boundary layer flow. Measurements are performed by means of two different techniques, namely Laser Doppler Anemometry and Stereo-Particle Image Velocimetry. These allow us to map the spatial evolution of the velocity statistics up to their third order moments. The study focuses in particular on the budget of the turbulent kinetic energy (t.k.e.) and the estimate of its mean dissipation rate. The experimental data-set is the basis for a detailed analysis of the reliability and the main limitations of a classical k-ϵ closure model. This has major implication for the numerical simulation of pollutant dispersion in the built environment.

APA, Harvard, Vancouver, ISO, and other styles

7

Cuhat, Daniel, and Patricia Davies. "An Experimental Approach to the Design of PVDF Modal Sensors." In ASME 2001 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/detc2001/vib-21537.

Full text

Abstract:

Abstract The principle of modal sensing is based on the use of a shaped PVDF piezoelectric film measuring strains on the surface of a bending beam and acting as a modal filter. So far, the use of this type of sensors has remained confined to studies involving uniform structures with classical boundary conditions. The goal of this paper is to present an experimental methodology for the design of a shaped modal sensor applicable to an non-uniform Euler-Bernoulli beam with arbitrary boundary conditions. This approach is illustrated with test data collected on a cantilever beam structure with a laser Doppler velocimeter.

APA, Harvard, Vancouver, ISO, and other styles

8

Sieker, Olaf, and Joerg R. Seume. "Effects of Rotating Blade Wakes on Separation and Pressure Recovery in Turbine Exhaust Diffusers." In ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-50788.

Full text

Abstract:

Highly efficient turbine exhaust diffusers can only be designed by taking into account the unsteady interactions with the last rotating row of the turbine. Therefore, a scale model of a typical gas turbine exhaust diffuser consisting of an annular and a conical diffuser is investigated experimentally. To investigate the influence of rotating wakes, a variable-speed rotating spoke wheel with cylindrical spokes as well as with NACA bladed spokes generates high-energy turbulent wakes simulating turbine rotor wakes. For the rotor with the NACA blades, the drive of the wheel is run in motor as well as in generator mode. Additional measurements in a reference configuration without a spoke wheel allow the detailed analysis of changes in the flow pattern. 3-hole pneumatic probes, static pressure taps, as well as a 2D-Laser-Doppler-Velocimeter (LDV) are used to investigate velocity profiles and turbulent characteristics. Without the wakes generated by a spoke wheel, the annular diffuser (with a 20° half cone opening angle) separates at the shroud for all swirl configurations. Increasing the swirl results in increasing pressure recovery at the shroud whereas the hub boundary is destabilized. For a non-rotating spoke rotor and low swirl numbers, the 20° annular diffuser separates at the shroud. Increasing the swirl number, a strong deceleration of the axial velocity at the shroud is generated without separation and a higher pressure recovery is achieved. The boundary layer at the shroud of the 20° annular diffuser separates for all operating points with the bladed rotor. A partly stabilized 20° annular diffuser can only be achieved for much higher values of the flow coefficient than that for the design point. At this high mass flow, the NACA-bladed rotor operates as a turbine, resulting in the generator mode of the electric drive. Contrary to the numerical design calculations, the flow at the shroud of a 15° annular diffuser does not separate for all swirl configurations in the experiment. Pressure recovery of the 15° annular diffuser can be increased by increasing the inlet swirl whereas the hub boundary layer is destabilized. For the NACA bladed rotor, the flow in the 15° annular diffuser as well as the pressure recovery strongly depend on the flow coefficient. For flow coefficients lower than the design value, the flow partly separates at the shroud whereas large flow coefficients result in increased pressure recovery. The pressure recovery also depends on the direction of swirl and thus the swirl number.

APA, Harvard, Vancouver, ISO, and other styles

9

Ahmed, Saad A., and Hany El Kadi. "Predictions of Turbulence Intensity in a Combustor Model Using Neural Network Analysis." In ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting collocated with 8th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-30834.

Full text

Abstract:

Predictions of turbulence intensity and continuous evolution of fluid flow characteristics in a combustor model are useful and essential for better and optimum design of gas turbine combustors. Many experimental techniques such as Laser Doppler Velocimetry (LDV) measurements provide only limited discrete information at given points; especially, for the cases of complex flows such as dump combustor swirling flows. For this type of flow, usual numerical interpolating schemes appear to be unsuitable. Neural Network Analysis (ANN) is proposed and the results are presented in this paper and are compared with the experimental data used for training purposes. This pilot study showed that artificial neural network is an appropriate method for predicting swirl flow characteristics in a model of a dump combustor. These techniques are proposed for better designs and optimization of dump combustors.

APA, Harvard, Vancouver, ISO, and other styles

10

Pagan, Luca, and Kelvin Lake. "Modal Analysis: A Comparison between Finite Element Analysis (FEA) and Practical Laser Doppler Vibrometer (LDV) Testing." In 2017 UKSim-AMSS 19th International Conference on Computer Modelling & Simulation (UKSim). IEEE, 2017. http://dx.doi.org/10.1109/uksim.2017.27.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!