【作者】 陈益亮；

【导师】 吕且妮；

【作者基本信息】 天津大学 ， 光学工程， 2010， 硕士

【摘要】 粒子场测量在工业、科研等领域具有重要的意义。激光干涉粒子成像技术是一种相对较新的粒子测量技术,它利用粒子散射光的干涉图得到粒子尺寸和位置信息,实现粒子场测量。本文对激光干涉粒子成像测量技术的理论及其在雾场中的应用进行了研究,所做的主要工作如下:1.基于几何光学模型对激光干涉粒子成像测量技术的基本理论进行了研究。2.分析了实验系统参数对可测粒径范围、最大可测粒子场浓度及粒径测量不确定性的影响,给出了设计最优化实验测量系统的方法。3.提出一种基于小波匹配和傅里叶变换技术的干涉图条纹数/条纹间距的提取方法,利用修正Rife方法对频率进行亚象素细分,并进行了计算机模拟。模拟结果:当重叠系数? <11.62%时,算法识别率高于90%,频率提取误差小于0.0185%。研究结果验证了该方法的可行性。4.利用连续半导体激光器和高分辨率CCD搭建激光干涉粒子成像测量实验系统,对直径为51.1?m和119.4?m的标准粒子进行测量。测量结果:粒子直径分别为49.79? 0.41?m和117.89? 1.49?m,相对误差分别为2.56%和1.26%。并应用于乙醇喷雾场和水喷雾场测量,给出了不同测量点处的粒径分布以及沿X方向、Y方向上的SMD变化曲线。实验结果证明了该方法在粒子场测量中的可行性。5.设计一种全相位多普勒测量实验系统,对直径为51.1?m和105?m的标准粒子分别进行点模式测量和条纹模式测量,测量相对误差分别为0.29%和3.81%。研究结果表明了该实验系统的可行性。更多还原

【Abstract】 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.更多还原