Investigation of highly laden particle jet dispersion by the use of a high-speed camera and parameter-independent image analysis

The present work deals with dispersion experiments of highly laden particle jets in turbulent cross-flow. While measurement techniques like phase-doppler anemometry (PDA) work well for dilute gas-particle flows and can deliver particle velocity and concentration, all these methods fail in measuring physical quantities for cases with high particle volume fractions. Nevertheless validation and calibration of numerical simulation models covering this flow regime require experimental data. Due to the strong interaction between the dispersion behavior and cross-flow turbulence the experimental data should provide high spatial and temporal resolution. This is achieved by the use of a high-speed camera, which inherently leads to huge amounts of image data. To be able to process the recorded images automatically a simple image processing method is presented which is based on analyzing single pixel lines at a given distance downstream of the injection lance. The strength of this method lies in the fact that it is not dependent on any preset factors and can therefore cover a large range of mass loadings. The presented experiments are well reproducible and are able to picture different flow regimes.

Graphical abstractThe dispersion of highly laden particle jets in turbulent cross-flow is investigated by the use of a high-speed camera. The particle distribution is extracted from the pixel luminosity and further analyzed for spatial and temporal information about the jet dispersion. The whole data processing procedure does not depend on any user defined parameter settings.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Powder injection with highly laden particle jets in crossflow ► Dispersion experiments with high temporal resolution by the use of a high-speed camera ► Fully automated data processing without any need for user-defined parameters ► Method applicable to experimental as well as numerical data for comparison ► Analysis of frequency content of particle distribution signals