ID 63

Efficient point-measurement sampling of spray plumes using volumetric distributions

 

Abstract:

Knowledge of spray characteristics is vital for many processes within industry and academic work. Phase-Doppler instruments are widely used to collect drop size, velocity, and flux data within sprays, but often require measurements at a larger number of points. Acquisition of these data can be time-consuming and costly. This work develops a testing method to allow efficient measurement of spray plumes of any arbitrary shape. The method consists of a two-phase approach. First, the spray is sampled to capture the distribution of the spray flux in the target plane, for example, using a mechanical patternator. This broad characterization is then analyzed with an iterative fitting algorithm which determines the necessary point-sample locations for a precision instrument focusing on the planar distribution gradients. In the second phase, the spray plume is sampled with a precision instrument at the predetermined locations. For validation, the fitting algorithm may be performed in parallel with the discrete sampling, with each iteration using a new point-sample. Point-sampling may continue until the desired accuracy is achieved. Validating experiments are performed in 1D with a mechanical patternator and in 2D using laser sheet imaging for phase one; phase two data are acquired using a Phase Doppler Interferometer. It is observed that the paired experimental method allows for accurate predictions of spatial spray characteristics and provides means for comparative analysis, improving outlier detection while preventing diminishing returns.