Abstract
An experimental setup was developed to perform wind tunnel measurements on a unit-ratio, 2D open cavity under perpendicular incident flow. The open cavity is characterized by a mixing layer at the cavity top, that divides the flow field into a boundary layer flow and a cavity flow. Instead of precisely replicating a specific type of inflow, such as a turbulent flat plate boundary layer or an atmospheric boundary layer, the setup is capable of simulating a wide range of inflow profiles. This is achieved by using triangular spires as upstream turbulence generators, which can modify the otherwise laminar inflow boundary layer to be moderately turbulent and stationary, or heavily turbulent and intermittent. Measurements were performed by means of time-resolved stereo PIV. The cavity shear layer is analyzed in detail using flow statistics, spectral analysis, and space–time plots. The ability of the setup to generate typical cavity flow cases is demonstrated for characteristic inflow boundary layers, laminar and turbulent. Each case is associated with a distinct shear layer flow phenomena, self-sustained oscillations for the former and Kelvin–Helmholtz instabilities for the latter. Additionally, large spires generate a highly turbulent wake flow, resulting in a significantly different cavity flow. Large turbulent sweep and ejection events in the wake flow suppress the typical shear layer and sporadic near wall sweep events generate coherent vortices at the upstream edge.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ashcroft G, Zhang X (2005) Vortical structures over rectangular cavities at low speed. Phys Fluids 17(1):015104. doi:10.1063/1.1833412
Basley J, Pastur LR, Lusseyran F, Faure TM, Delprat N (2010) Experimental investigation of global structures in an incompressible cavity flow using time-resolved PIV. Exp Fluids 50(4):905–918. doi:10.1007/s00348-010-0942-9
Basley J, Pastur LR, Delprat N, Lusseyran F (2013) Space-time aspects of a three-dimensional multi-modulated open cavity flow. Phys Fluids 25(6):064105. doi:10.1063/1.4811692
Bian S, Driscoll JF, Elbing BR, Ceccio SL (2010) Time resolved flow-field measurements of a turbulent mixing layer over a rectangular cavity. Exp Fluids 51(1):51–63. doi:10.1007/s00348-010-1025-7
Chang K, Constantinescu G, Park SO (2006) Analysis of the flow and mass transfer processes for the incompressible flow past an open cavity with a laminar and a fully turbulent incoming boundary layer. J Fluid Mech 561:113. doi:10.1017/S0022112006000735
Chatellier L, Laumonier J, Gervais Y (2004) Theoretical and experimental investigations of low Mach number turbulent cavity flows. Exp Fluids 36(5):728–740. doi:10.1007/s00348-003-0752-4
Gharib M, Roshko A (1987) The effect of flow oscillations on cavity drag. J Fluid Mech 177(1):501. doi:10.1017/S002211208700106X
Haigermoser C, Vesely L, Novara M, Onorato M (2008) A time-resolved particle image velocimetry investigation of a cavity flow with a thick incoming turbulent boundary layer. Phys Fluids 20(10):105101. doi:10.1063/1.2990043
Hunt J, Wray A, Moin P (1988) Eddies, streams, and convergence zones in turbulent flows. In: Studying turbulence using numerical simulation databases, 2 proceedings of the 1988 summer program, pp 193–208. http://adsabs.harvard.edu/abs/1988stun.proc..193H%EF%BF%BD%C3%9C
Hussain M, Lee B (1980) An investigation of wind forces on three-dimensional roughness elements in a simulated atmospheric boundary layer flow Part 2. Flow over large arrays of identical roughness elements and the effect of frontal and side ratio variations. Technical report, Dept of Building Science, University of Sheffield, Report BS 56
Immer M (2015) Cavity flow PIV dataset. http://www.carmeliet.arch.ethz.ch/ResearchDatabase/CavityFlow. Accessed 10 Sept 2015
Irwin H (1981) The design of spires for wind simulation. J Wind Eng Ind Aerodyn 7(3):361–366. doi:10.1016/0167-6105(81)90058-1
ITTC (2008) ITTC recommended procedures and guidelines—uncertainty analysis particle imaging velocimetry. Technical report
Johnson W, Ludwig F, Dabberdt W, Allen R (1973) An urban diffusion simulation model for carbon monoxide. J Air Pollut Control Assoc 23(6):490–498. doi:10.1080/00022470.1973.10469794
Kang W, Sung HJ (2009) Large-scale structures of turbulent flows over an open cavity. J Fluids Struct 25(8):1318–1333. doi:10.1016/j.jfluidstructs.2009.06.005
Kang W, Lee SB, Sung HJ (2008) Self-sustained oscillations of turbulent flows over an open cavity. Exp Fluids 45(4):693–702. doi:10.1007/s00348-008-0510-8
Kellnerová R, Kukačka L, Jurčáková K, Uruba V, Jaour Z (2012) PIV measurement of turbulent flow within a street canyon: detection of coherent motion. J Wind Eng Ind Aerodyn 104–106:302–313. doi:10.1016/j.jweia.2012.02.017
Knisely C, Rockwell D (1982) Self-sustained low-frequency components in an impinging shear layer. J Fluid Mech 116(1):157. doi:10.1017/S002211208200041X
Kostas J, Soria J, Chong M (2002) Particle image velocimetry measurements of a backward-facing step flow. Exp Fluids 33(6):838–853. doi:10.1007/s00348-002-0521-9
LaVision (2011a) DaVis 8.0 Software Manual. LaVision GmbH
LaVision (2011b) FlowMaster Manual. LaVision GmbH
Liu X, Katz J (2013) Vortex-corner interactions in a cavity shear layer elucidated by time-resolved measurements of the pressure field. J Fluid Mech 728:417–457. doi:10.1017/jfm.2013.275
Nicholson SE (1975) A pollution model for street-level air. Atmos Environ 9(1):19–31. doi:10.1016/0004-6981(75)90051-7
Nobach H, Tropea C (2007) Fundamentals of data processing. In: Tropea C, Yarin A, Foss J (eds) Springer handbook of experimental fluid mechanics. Springer, Berlin, pp 1399–1417. doi:10.1007/978-3-540-30299-5_23
Nunez M, Oke TR (1977) The energy balance of an urban canyon. J Appl Meteorol 16(1):11–19. doi:10.1175/1520-0450(1977)016<0011:TEBOAU>2.0.CO;2
Oke T (1988) Street design and urban canopy layer climate. Energy Build 11(1–3):103–113. doi:10.1016/0378-7788(88)90026-6
Rockwell D (1977) Prediction of oscillation frequencies for unstable flow past cavities. J Fluids Eng 99(2):294. doi:10.1115/1.3448746
Rockwell D, Naudascher E (1978) Review–self-sustaining oscillations of flow past cavities. J Fluids Eng 100:14. doi:10.1115/1.3448624
Roshko A (1955) Some measurements of flow in a rectangular cutout. Technical Report August 1955. http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA377172
Rossiter J, Britain G (1964) Wind-tunnel experiments on the flow over rectangular cavities at subsonic and transonic speeds. Technical report. http://repository.tudelft.nl/view/aereports/uuid:a38f3704-18d9-4ac8-a204-14ae03d84d8c/
Salizzoni P, Marro M, Soulhac L, Grosjean N, Perkins RJ (2011) Turbulent transfer between street canyons and the overlying atmospheric boundary layer. Bound Layer Meteorol 141(3):393–414. doi:10.1007/s10546-011-9641-1
Sarohia V (1975) Experimental and analytical investigation of oscillations in flows over cavities. PhD thesis. http://thesis.library.caltech.edu/1597/
Welch P (1967) The use of fast Fourier transform for the estimation of power spectra: a method based on time averaging over short, modified periodograms. IEEE Trans Audio Electroacoust 15(2):70–73. doi:10.1109/TAU.1967.1161901
Wieneke B (2005) Stereo-PIV using self-calibration on particle images. Exp Fluids 39(2):267–280. doi:10.1007/s00348-005-0962-z
Wieneke B (2014) Generic a-posteriori uncertainty quantification for PIV vector fields by correlation statistics. ltcesdemistutlpt pp 7–10. http://ltces.dem.ist.utl.pt/lxlaser/lxlaser2014/finalworks2014/papers/03.5_2_560paper.pdf
Acknowledgments
This work was supported by the Hartmann Müller-Fonds on Grant ETH-32 11-2.
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Immer, M., Allegrini, J. & Carmeliet, J. Time-resolved and time-averaged stereo-PIV measurements of a unit-ratio cavity. Exp Fluids 57, 101 (2016). https://doi.org/10.1007/s00348-016-2186-9
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/s00348-016-2186-9