Abstract
In this study, a digital holographic technique has been developed for measuring 3D unsteady velocity distribution from a time series digital hologram, and the performance is examined by numerical simulation and experiment with a high speed camera. For the method using the phase that is relative to that on the background, the measurement accuracy has been improved as compared with our previous method using light intensity information. In numerical simulation, it is shown that RMS error in depth is 65μm for particle size 25μm. If this technique is applied to the measurement of the bubbly flow in 3D space, 3D velocity vectors are going to be successfully obtained to confirm the feasibility of this technique in real flow measurements.
