Experimental investigation of vortex ring interaction with a - PDF document

See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/341508721 Experimental investigation of vortex ring interaction with a permeable flat surface – Presentation Presentation · May 2006 CITATIONS READS 0 11 3 authors , including: C. Naaktgeboren Paul S Krueger Federal University of Technology - Paraná/Brazil (UTFPR) Southern Methodist University 49 PUBLICATIONS 57 CITATIONS 102 PUBLICATIONS 1,192 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Natural Convection Inside Porous Media View project Analysis of gas transport and micro-circulation in pulmonary capillaries View project All content following this page was uploaded by C. Naaktgeboren on 20 May 2020. The user has requested enhancement of the downloaded file.

Experimental Investigation of Vortex Ring Interaction Experimental Investigation of Vortex Ring Interaction with a Permeable Flat Surface with a Permeable Flat Surface Christian Naaktgeboren Paul S. Krueger José L. Lage Department of Mechanical Engineering Southern Methodist University Dallas, Texas 3 rd International Conference on Applications of Porous Media – 3ICAPM Monday–Saturday, May 29–June 3, 2006; Marrakech, MOROCCO Work partially supported by NSF grant CTS–0347958

Background: Vortex Ring Generation Background: Vortex Ring Generation Classical Piston-Cylinder Mechanism: U D = 0 Re U p ( t ) ν u J ( r , t ) U 0 D Starting Jet or “Pulse” L t t p Parameters: [Didden, 1977] a) Time history of piston velocity (velocity program) b) L/D c) Reynolds Number d) Orifice/nozzle Geometry

Motivation for Present Investigation Motivation for Present Investigation • Interaction of a compact vortical structure with a complex interface – Vorticity generation – Effect on convection and vorticity transport – Kinetic energy dissipation

Examples Examples • Nature – Jellyfish with tentacles – Microbursts – Vortex-structure interaction • Engineering – Chemical reactions near/within PM – Filter cleaning – Electronics cooling – Sampling of contaminants on clothing

Previous Work – Vortex Ring Impingement Previous Work – Vortex Ring Impingement • Collision of two coaxial vortex rings – Helmholtz, H., 1867; – Dyson, F. W., 1893; – Lim, T. T., Nickels T. B., and Chong, M.S., 1991. • Flat, rigid, impermeable surface – Magarvey, R. H., and MacLatchy C. S., 1963; – Cerra, A. W., Smith, C. R., 1983. – Verzicco, R., and Orlandi, P., 1994. • Actively controlled mass flux through wall – Koumoutsakos, P., 1997. • Thin porous screen (flow visualization) – Naaktgeboren C. et al , 2005.

Experimental Configuration Experimental Configuration PRESSURE VESSEL AIR NC WATER CCD CAMERA PLANAR PISTON-CYLINDER MECHANISM LIGHT SHEET D VORTEX L RING TARGET PULSE/DELAY Nd:YAG LASER GENERATOR ARGON ION LASER • Measurement techniques – Planar Laser Induced Fluorescence (PLIF) – Digital Particle Image Velocimetry (DPIV)

PLIF & DPIV Raw Data PLIF & DPIV Raw Data PLIF DPIV

DPIV – Processed Results DPIV – Processed Results Velocity Field Vorticity = ∇ × ω u

Porous Targets Porous Targets Target #2: Target #3: Surface fraction ( φ ): (58±4) % Surface fraction ( φ ): (86.6±0.3) % Thickness (e): (267±13) µm Thickness (e): (594±5) µm D/D pore : 29.4 D/D pore : 8.75 Pore aspect ratio: 1.57 Pore aspect ratio: 1.02

Flow evolution – φ =0, Re=3000, L/D=1.00 Flow evolution – φ =0, Re=3000, L/D=1.00

Vorticity ( ω θ ) – φ =0 Vorticity ( ω θ ) – φ =0

Kinetic Energy Distribution – φ =0 Kinetic Energy Distribution – φ =0

Flow evolution – φ =0.58, Re=3000, L/D=1.00 Flow evolution – φ =0.58, Re=3000, L/D=1.00

Vorticity ( ω θ ) – φ =0.58 Vorticity ( ω θ ) – φ =0.58

Vorticity – φ =0.58, Re=3000, L/D=1.00 Vorticity – φ =0.58, Re=3000, L/D=1.00 Levels every 2.5 s −1 Levels every 1.0 s −1

Kinetic Energy Distribution – φ =0.58 Kinetic Energy Distribution – φ =0.58

Flow evolution – φ =0.866, Re=3000, L/D=1.00, ψ Flow evolution – φ =0.866, Re=3000, L/D=1.00, ψ

Vorticity ( ω θ ) – φ =0.866 Vorticity ( ω θ ) – φ =0.866

Vorticity – φ =0.866, Re=3000, L/D=1.00 Vorticity – φ =0.866, Re=3000, L/D=1.00 Levels every 2.5 s −1 Levels every 1.0 s −1

Kinetic Energy Distribution – φ =0.866 Kinetic Energy Distribution – φ =0.866

Total Kinetic Energy History Total Kinetic Energy History φ =58.0% φ =86.6% T ∫∫ 2 = π u r dr dz ρ

Kinetic Energy Relations Kinetic Energy Relations −∆ T/T (%) φ VR1: T/ ρ (mm 5 /s 2 ) T VR2 /T VR1 (%) T VRT /T VR1 (%) 107±2 2.66±0.38 2.48±0.25 94.8±0.6 0.58 0.866 108.4±0.6 negligible 46.1±0.6 53.9±0.6

View publication stats View publication stats Conclusions Conclusions • High porosity targets • Low porosity targets – No vortex rebound – Vortex rebound • Separated features • Flow separation convected downstream • Secondary vortices – Significant through- – Reduced through-flow flow – Intense viscous – Moderate viscous dissipation dissipation – Reorganization of the – Spreading of the transmitted ring vortex core