Study On The Theoryand Experiment Of Interferometric Particle Imaging

The measurement of particle field is important in science and engineering and the like fields. Interferometric particle imaging (IPI) technique is a relatively new particle measuring technique which can obtain the size and the location of particle by the interferogram of particle scattering light. The paper centers about the theory of the IPI technique and its application in spray field, the main work as follows has been done:1. The basic theory of the IPI technique is studied based on geometrical optics model (GOM).2. The impact of experimental parameters on the measurable particle size range, the maximum measurable concentration of the particle field and the uncertainty of particle diameter measurement is analyzed for a given experimental system, and an optimized experimental system can be designed.3. A method of extracting the number of fringes/spacing of interferogram based on wavelet matched filter and FFT technique is proposed, and sub-pixel accuracy of the extracted frequency is obtained with the modified Rife algorithm and computer simulations are performed. The simulation results are that the recognition ratio is more than 90% and the frequency error is less than 0.0185% for the overlap coefficient ? <11.62%. The research results show that the method presented in this paper is feasible.4. The experimental system of IPI has been set up with CW semiconductor laser and high-resolution CCD, and the experiments are conducted for the diameter 51.1?m and 119.4?m standard particles. The measurement results are that the particle diameters are 49.79? 0.41?m and 117.89? 1.49?m, and the relative errors 2.56% and 1.26% respectively. And the alcohol spray and the water spray are measured and the particle size distribution of different measuring points and SMD variation curves along X axis and Y axis are given. From the experimental results, it can be seen that the IPI technique is feasible in the particle field measurement.5. The experimental system of Global phase doppler (GPD) technique is designed, and the experiment for the diameter 51.1?m and 105?m standard particles are carried out with glare points and fringe pattern respectively, and the relative errors are 0.29% and 3.81%. And the research results testify the feasibility of the experimental system presented in this paper.