Optical and digital holography for spray measurement

Aiming at the problems that the development of holographic plate is cumbersome and the acquisition of the reconstruction image is time-consuming during the spray measurement with optical holography, a method of simultaneously using optical holography and digital holography was proposed, and a system consisting of in-line optical holography, in-line digital holography and digital delay signal generator was established. Spray field produced by doublehole direct injection nozzle was measured by the system. The reconstructed images of optical holography and digital holography were obtained during a single measurement, and they were in good agreement with each other. The range of the field of view was 27.87 mm4.77 mm and 27.59 mm6.67 mm, corresponding to optical and digital image reconstruction, and the acquisition time of digital holographic image reconstruction was only 8 s. The results show that a real-time assessment for the experiment effect can be made by the digital holographic image reconstruction, during the joint measurement of optical holography and digital holography, so the efficiency of holographic measurement experiment for spray field is improved.