Application of the Tomographic Laser Doppler Anemometry (TDLA) to a fuel spray

In some applications, the size of the probe volume of a Laser Doppler Anemometry (LDA) system limits the spatial resolution of the measurement. If the probe volume is far from the LDA probe due to limited optical access, the probe volume cannot be assumed as a point. It becomes an ellipsoid, which allows no spatial correlation of a registered burst. In this work, a tomographic algorithm is presented to locate registered bursts along an extended LDA probe volume by means of a tomographic reconstruction with the inverse Radon transformation. The integral information of velocity and particle number within the probe volume is analyzed to obtain sub-volume resolution, which is only limited by the increment of traversing the probe volume through the flow field, the width of the probe volume and the number of projections. The algorithm is used to reconstruct the velocity field of a fuel spray from LDA measurements at different injection pressures.

► Tomographic Laser Doppler Anemometry.
► Provides sup-probe volume resolution.
► Requires simple experimental setup.
► Detailed investigation of droplet velocities in a fuel spray.