流体,灰尘中速度矢量场,温度场检测方案(粒子图像测速)

Preliminary measurements of kinetic dust temperature using stereoscopic particle image velocimetryJeremiah Williams， Edward ThomasPlasma Sciences Laboratory Abstract A dusty (or complex)plasma is a four-component system composed of ions， electronsneutral particles and charged microparticles. The presence of the microparticle (i.e.，dust) component alters the plasma environment， giving rise to a wide variety of newplasma phenomena. Recently， the Auburn Plasma Sciences Laboratory (PSL) hasacquired and installed a stereoscopic PIV (stereo-PIV) diagnostic tool for dustyplasma investigations [Thomas， et. al， Phys. Plasmas， 11. L37 (2004)1. Thispresentation discusses the use of the stereo-PIV technique for determining the velocityspace distribution function of the microparticle component of a dc glow dischargedusty plasma. These distribution functions are then used to make preliminaryestimates of the kinetic temperature of the dust component. The data is compared to asimple energy balance model that relates the dust temperature to the electric field andneutral pressure 3DPX and Stereoscopic PIV 3DPX i Stereo-PIV hardware The 3DPX chamber is based onmodified ISO-100， six-way crossconfiguration with a large viewingwindow to optimize 3Dvelocityvector reconstructionArgon de glow discharge plasmasBiased anode and biased cathode areused to generate the plasmaMicroparticles are placed on a traybelow the electrodes. Dual， pulsed Nd：YAG lasers Frequency doubled laser source (532 nm)· 15 Hz firing rate @100 mJ/pulse Two 1340 x 1040 pixel CCD cameras5 frames/sec in stereo-PIV mode Lasers and cameras are mounted ona single linear motion“arm" tohatcinmaintain a fixed distance between the laser sheet and cameras， Example of a PIV measurement in 3DPX device. Orientation of cameras and lascr on 3DPX A Stereoscopic PIV setup consists of two 2D PIV systems oriented on different viewing axes. The cameras on 3DPX are arranged for backward-forward scattering. Each camera measures the projection of thevelocity vector in the plane of the laser sheet. The viewing orientation of each camera witlrespect to the laser sheet can be determinedusing an empirical calibration process Using the results from each 2D PIV systemand a mapping function that is generatedfrom the calibration process， the three component velocity vector can be computed. Source： DaVis FlowMaster SoftwanManual for DaVis 6.2. August 2002， pp 125. A LaVision software package， DaVis， is used to control the PIV hardware (camera， laserand motion system) and to compute the three-dimensional velocity vectors， 3D system accurately reproduces what is measured by the 2D system. However. thedetailed structure is much more apparent when using the 3D system.