Micro-PIV

The micro-particle-image-velocimetry (micro-PIV) and planner-laser-induced-fluorescence (PLIF) setup in the COIFPM is a unique machine capable of measuring the velocity field and the concentration (e.g. contaminant mass transfer) in two individual fluids at two different fields of view (FOV), simultaneously. The two fields of view cover the whole-micromodel scale and the pore-scale velocities, each of which providing very useful information regarding the physics of fluid flow and their interaction with each other and the solid walls of the medium. The large-FOV module of the system consists of two 29 Mega-Pixels (MP) digital CCD cameras with 4.5 frames/second (fps), a 4X objective lens with the numerical aperture of 0.2, a 532 nm Nd:YAG dual cavity laser with 15 Hz pulse repetition rate and 70 mJ energy and a beam-splitting box. The beam splitting box includes a dichroic mirror that directs the laser light to the fluorescent particles dispersed in fluids. The cameras for the small-FOV module of the system are high speed CMOS with 800 fps speed at a resolution of 4 MP. The light for this part of the system is provided by a 527 nm wavelength Nd:YLF dual oscillators with 1000 Hz pulse repetition rate and 15 mJ total pulse energy. This part of the system is equipped with 10X and 40X objective lenses with numerical apertures of 0.3 and 0.6, respectively. The light from lasers passes through several optical filters and reflects from different optical mirrors to finally reach the cameras through a Nikon inverted microscope. One of the cameras in the large-FOV and one in the small-FOV section are equipped with filters that allow the capture of the light reflected from only orange fluorescent particles that are dispersed in one of the fluids. The other two cameras are equipped with optical filters that pass the light from the red fluorescent particles that are dispersed in the other fluid. The optical filters in both parts of the system are identical.