Particle Dynamics Laboratory

The Particle Dynamics Laboratory investigates problems associated with the formation, deposition, resuspension and transport of micrometer-sized particles or droplets (electrically neutral or charged) in various pressure environments. Because its efforts primarily are experimental, the laboratory is equipped with state-of-the-art equipment to visualize and measure droplet/particle characteristics under both atmospheric and vacuum conditions. Emphasis is placed on conducting detailed and accurate experiments that provide archival data from which correct models of the underlying physical processes can be developed and assessed.

The Particle Dynamics Laboratory's facilities include a large vacuum/pressure chamber that is used to investigate particle production, transport and deposition primarily in vacuum environments and a large enclosure for atmospheric particle generation, transport and deposition research. Also operational is a rectangular vacuum/pressure chamber that is used for particle/surface impact experiments. The laboratory further contains equipment for the generation of monodisperse and polydisperse particles, high voltage supplies, and electrometer and charge detector for particle charge measurement, still and video camera equipment for stroboscopic and pulsed laser light-sheet visualization of in-flight micrometer-sized particles, computer systems with A/D, D/A and controller capabilities, and hot-wire anemometry, laser aerosol spectrometry and two new advanced light-scattering systems (a two-component Phase Doppler Particle Analyzer and a Particle Counter Sizer Velocimeter) for fluid and particle velocity and particle concentration measurements. The most recent research on microparticle resuspension and transport from surfaces uses microphotography (still and video), particle image velocimetry, and phase Doppler and hot-wire anemometry in a new 20.3 cm by 20.3 cm (8 in. by 8) in. cross-sectional area aerosol wind tunnel. These diagnostics help to full characterize the motion of an individual microparticle during resuspension and its subsequent motion in the air. In addition, subsidiary experiments are being conducted to characterize the surface "roughness" using atomic force microscopy and to directly measure the rotation rates of microparticle using lateral effect detectors.

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Strobed Laser Light Sheet Image of a 50µm
Diameter Microsphere Impacting a Surface at 45 Degrees

 

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EHD Spray Visualization using a Laser Light Sheet:
Probe on-axis; Horiz. Sheet- Var.; Z from 0 - 40 mm; 15 kV

 

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EHD Spray Visualization using a Laser Light Sheet:
Probe off-axis; Vert. Sheet; R = 5 mm; 15 kV

Direct comments, questions, and corrections to amedept@nd.edu