Development of a Compact & Easy-to-Use 3-D Camera for High Speed Turbulent Flow Fields.

摘要

A methodology, termed plenoptic particle image velocimetry (PIV), was developed and demonstrated for the measurement of three-dimensional, three- component velocity fields in high-speed turbulent flow fields. The concept is based on light-field imaging of particles where a plenoptic camera is used to measure both the position and angle of light rays scattered by particles contained in the flow field. Tomographic algorithms are applied to plenoptic camera data to determine the 3D position of particles contained in the flow field and cross-correlation algorithms are used to determine the displacement of particles in two successive images. A prototype camera was designed, built and used to demonstrate the viability of the technique in practice. A synthetic image generation tool was developed to simulate the camera and investigate the technique's accuracy. Demonstration experiments included 3D velocity measurements of a turbulent boundary layer formed on a wind tunnel wall and a heated, supersonic axisymmetric jet. Overall, plenoptic PIV is shown to be a viable 3D flow measurement technique with its main strengths being its compact form factor, simple experimental arrangement, limited need for optical access and overall ease of use.