000004193 001__ 4193
000004193 005__ 20141118185748.0
000004193 04107 $$acze
000004193 046__ $$k2005-05-31
000004193 100__ $$aBosch, Harold
000004193 24500 $$aParticle Image Velocimetry for Flow Visualization around Generic Bridge Shapes

000004193 24630 $$n10.$$pProceedings of the Tenth Americas Conference on Wind Engineering
000004193 260__ $$bAmerican Association for Wind Engineering, 2005
000004193 506__ $$arestricted
000004193 520__ $$2eng$$aThis paper examines the flow field around generic bridge shape models using the particle image velocimetry technique (PIV). The experiments were conducted in a small demonstration wind tunnel of “continuous circuit” design. Vanes in the corners of the tunnel turn the airflow and screens and honeycombs smoothen the flow. The tunnel has a quadratic working section (0.25m x 0.25m). Sets of different models “generic bridge shapes” are studied for flow visualization. Models are fabricated out of Plexi-glass to avoid shadows and reflections in the light sheet. The models are simplified versions of existing bridge decks excluding railing and other details. The scale of the section models is designed to be 1 : 225 resulting in an average width of 130 mm and a height of 18.4 mm. All models were mounted vertically in the tunnel. The angle of attack was varied between -15° and +15° using 5° increments. The PIV set-up used for these experiments was self-developed. The correlation algorithms were programmed in LabVIEW and IMAQ Vision. Nonlinear fit functions are used for calibration and image de-warping. A high-speed, high-resolution interline-transfer CCD digital camera that features a built in electronic shutter with exposure times as short as 127 microseconds is used for recording. A dual laser-head system designed to provide a highly stable green light source for PIV applications generated the light sheet. Detection and correction of false vectors and calculation of derived flow magnitudes are two features employed by the PIV method that enhance the quality of the delivered PIV vector maps. After the velocity flow fields are validated, standard differentiation schemes can be used to perform numerical vector field operations to compute streamlines and vorticity, even in the very complex flow patterns that occur around bridge decks. The vorticity field estimate is used to determine vortex-shedding frequencies. Drag forces are computed using averaged velocity flow fields. 

000004193 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000004193 653__ $$aGeneric Bridge Shapes, Particle Image Velocimetry, Bridge Engineering, Wind Engineering

000004193 7112_ $$aTenth Americas Conference on Wind Engineering$$cBaton Rouge, Louisiana (US)$$d2005-05-31 / 2005-06-04$$g10ACWE
000004193 720__ $$aBosch, Harold$$iKerenyi, Kornel
000004193 8560_ $$ffischerc@itam.cas.cz
000004193 8564_ $$s990701$$uhttps://invenio.itam.cas.cz/record/4193/files/014-Bosch.pdf$$yOriginal version of the author's contribution as presented on CD, , paper No. 014.
000004193 962__ $$r4178
000004193 980__ $$aPAPER