基于光场成像及温敏磷光粒子的三维速度和温度同步测试技术

The proposed research seeks to develop a simultaneous 3D velocity and temperature measurement technique by using Light Field imaging and thermographic phosphor sensing techniques. Theoretical analysis on the velocity and temperature response of thermographic phosphors will be firstly performed in order to provide guidance for selecting suitable phosphors as PIV tracers. Meanwhile, a synthetic image generator will be developed to simulate light field phosphor images produced by the dual-Light-Field camera system, so as to provide a powerful tool for the subsequent simulation and algorithm validation analysis. Based on wave optics and the compressed sensing technique, high resolution light field 3D reconstruction algorithms will then be developed and tested by using the synthetic light field image generator. Later on, one in-house high resolution Light Field camera will be constructed according to the plenoptic imaging principle. It will be combined with our existing in-house high resolution Light Field camera to develop the dual-Light-Field camera system. After these tasks being successfully accomplished, calibration experiments will be carried out to establish the relation between phosphor life-time and flow temperature. This will be followed by a series of low speed water jet and high speed air jet experiments, in order to determine the measurement accuracy and spatial resolution of this novel technique. Lastly, the proposed 3D velocity and temperature distribution simultaneous measurement technique will be applied to turbine blade filming-cooling experiments, it is believed that detailed knowledge on the flow field and temperature distribution provided by the light field and thermographic phosphor based technique will provide valuable insights for developing advanced filming-cooling techniques.

基于具有自主知识产权的双光场相机硬件系统、结合温敏磷光测温技术，本项目旨在发展一种三维速度场、空间温度分布的高精度同步测试技术。首先开展温敏磷光颗粒性能理论分析，获得温敏颗粒的速度和温度响应时间；并发展双光场相机粒子图像数字合成平台，精确模拟温敏粒子所发射的磷光经镜头、微透镜阵列到达 CCD 芯片后所形成的光场图像；随后分别基于波动光学和压缩感知技术，发展高精度双光场相机粒子三维重构算法，并完成数值验证分析；其次根据光场成像原理，精密封装自主光场相机一套，与现有光场相机组合搭建双光场相机成像系统；同时开展温敏颗粒标定实验，建立磷光寿命与流场温度的精密关系；然后分别开展低速水槽射流、高速空气射流实验，验证双光场相机温敏颗粒三维速度、温度同步测试技术的测量精度；最后利用所发展的新颖技术开展气膜冷却机理实验研究，为发展高效气膜冷却技术提供高精度的三维速度、空间温度同步测试数据。

本项目发展了具有自主知识产权的双光场相机硬件技术、双光场PIV三维流场测量技术以及基于温敏磷光颗粒的速度温度场同步测量技术。先后完成了温敏磷光颗粒成像理论分析，双光场相机数字图像合成平台开发，流场示踪粒子浓度对重构质量影响、双光场相机夹角对重构质量和空间分辨率影响的分析。开发了双光场相机三维粒子重构算法、移轴光场校准算法，并采用GPU加速，实现高效重构算法。完成了基于双光场相机的低速水槽射流验证实验，搭建了直升机涡轴发动机燃烧室旋流发生器实验台，并完成了双光场相机流场测试实验，以及与四相机TomoPIV的对比验证。