Three-dimensional analysis of microwave generated plasmas with extended planar laser-induced fluorescence

2007 ◽  
Vol 78 (4) ◽  
pp. 043508 ◽  
Author(s):  
U. Stopper ◽  
P. Lindner ◽  
U. Schumacher
Author(s):  
Kerstin Kling ◽  
Dieter Mewes

Micromixing is visualized inside a stirred vessel by using two different optical measurement techniques, the optical tomography and the Planar Laser Induced Fluorescence technique (PLIF). In order to distinguish between macro- and micromixing, a mixture of two dyes is injected into the mixing vessel. One of the dyes is an inert dye whereas the second dye is undergoing a fast chemical reaction with the vessel content. The distribution of the inert dye serves as a tracer for the macromixing but does not predicate the mixing quality on the nano scale. The chemical reaction requires mixing on the molecular scale. Therefore the reacting dye, which is changing its emission characteristics during the reaction, indirectly visualizes the micromixing. The tomographical dual wavelength photometry is used to measure the three-dimensional, transient concentration fields in the whole vessel at the same time. Measurements with the Planar Laser Induced Fluorescence technique are performed in an arbitrary plane of the vessel. This restriction on a two-dimensional concentration field is recompensed with a much higher spatial resolution which allows to visualize small scale structures in the order of mm. For both techniques low Reynolds number measurements are performed in a mixing vessel equipped with a Rushton turbine. Results are presented as two- or three-dimensional concentration fields. Areas of micromixing are detected by calculating the local degree of deviation from the concentration fields. They are depending on the injection position of the dye and are mainly found in the boundary layer of the lamellas.


2000 ◽  
Author(s):  
T. Muruganandam ◽  
Srihari Lakshmi ◽  
A. Ramesh ◽  
S. Viswamurthy ◽  
R. Sujith ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2607
Author(s):  
Siying Chen ◽  
Yuanyuan Chen ◽  
Yinchao Zhang ◽  
Pan Guo ◽  
He Chen ◽  
...  

Although it is quite challenging to image and analyze the spatial distribution of bioaerosols in a confined space, a three-dimensional (3D) modeling system based on the planar laser-induced fluorescence (PLIF) technique is proposed in this paper, which is designed to analyze the temporal and spatial variations of bioaerosol particles in a confined chamber. The system employs a continuous planar laser source to excite the fluoresce, and a scientific complementary metal oxide semiconductor (sCMOS) camera to capture images of 2048 × 2048 pixels at a frame rate of 12 Hz. While a sliding platform is moving back and forth on the track, a set of images are captured at different positions for 3D reconstruction. In this system, the 3D reconstruction is limited to a maximum measurement volume of about 50 cm × 29.7 cm × 42 cm, with a spatial resolution of about 0.58 mm × 0.82 mm × 8.33 mm, and a temporal resolution of 5 s. Experiments were carried out to detect the PLIF signals from fluorescein aerosols in the chamber, and then 3D reconstruction was used to visualize and analyze the diffusion of aerosol particles. The results prove that the system can be applied to clearly reconstruct the 3D distribution and record the diffusion process of aerosol particles in a confined space.


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