基于多曝光模糊成像的流动多参数场测量方法研究

对流场测量方法的研究在科学机理探索与工程技术发展上都具有十分重要的意义。粒子图像测速（PIV）和粒子追踪测速（PTV）是流场测量的重要方法，但存在三维匹配算法复杂、精细结构测量时景深局限等问题，且相关仪器价格十分昂贵。在前期研究基础上，本申请提出采用单帧多曝光法获得粒子的连续多段运动轨迹，拟解决速度二义性问题；发展针对颗粒轨迹图像的识别和处理算法，获得颗粒运动多参数信息，包括速度、加速度和受力等；提出利用离焦特性处理景深外颗粒图像，并开展成像系统光学传递特性研究，实现基于此的三维信息提取；分析复杂流动中颗粒的运动特性，探讨颗粒的示踪性能并进行多曝光测量参数的优化；分析颗粒与流体的时空关联性，建立欧拉和拉格朗日两种坐标系下参数的对应关系，反演重构流体流动的多参数场；从而发展一种基于多曝光模糊图像的流动多参数场测量新方法，为微尺度、多维或多相等复杂流动、传热与燃烧问题的研究奠定测量基础。

Study of the flow field measurements is of great significance in scientific researches and development of engineering technologies. Particle image velocimetry (PIV) and particle tracking velocimetry (PTV) are important methods to measure the flow field, but there are some problems such as complex three-dimensional matching algorithm, depth of field limitation in fine-structure measurements, and very expensive instrument. Based on the preliminary researches, this application proposes multi-exposure on single frame method to solve the speed ambiguity using consecutive segments of particle trajectories. With study of identification and processing algorithms for trajectory images, multi-parameter information for motion will be obtained including speed, acceleration and force, etc. It proposes making use of defocus characteristics to process particle images outside the depth of field, and realizing three-dimensional information extraction based on the optical transmission characteristics of the imaging system. By analyzing the particles movement in complex flow, tracing performance of particles will be explored and parameters will be optimized for multi-exposure measuring system. Through analysis of spatial and temporal association with the fluid and particles, relationship of the parameters between Euler and Lagrange coordinate systems will be established, and the inversion and reconstruction of multi-parameter fields for fluid flow will be realized. Thus a novel multi-parameter field measurements method will be developed based on multi- exposed and blurred images, laying measuring basis for complex flow, heat transfer and combustion problems such as micro-scale, multi-dimensional or multi-phase problems.