The optimum design and operation of a gas liquid solid flow system depend on the ability to accurately predict the fundamental properies of the hydrodynamics, heat and mass transfer and so on. Identification of the flow regimes is also needed to understand the overall system performance. This comprehensive review describes both the experimental and modeling studies of the fundamental characteristics of gas-liquid-solid three phase flow.

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The present paper concerns the motion of particles in turbulent flow and in particular the details of the fluid and particle velocity field in a plane twodimensional particulate jet flow emerging centrically into a plane two-imensional upward facing duct flow of air. Laser-Doppler anemometry was employed to map out the flow yielding local mean velocity distributions for both, the upward gas flow and the particle motion as well as local information of the rms-value of the turbulence velocity fluctuations of both phases. The particle size was known in the experiments. This permitted a combined amplitude/visibility signal discrimination to be employed to separate the particle and fluid velocity information in the laser-Doppler signals. A counting procedure was employed to determine the local volume fraction of the particles.
The flow was studied under several inlet flow conditions. The dispersion of particles from the jet was studied extensively scanning the flow field downstream of the particle jet inlet. Several flow settings of the two outer and the inner inlet channels were investigated and laser Doppler measurements were supplemented by wall pressure recordings. The complete set of data provides a basis for flow predictions yielding computer programs in which experimental findings, on turbulent particulate flows are stored. Such programs can afterwards be successfully employed to study details of particle erosion near walls, flow of liquid sprays, combustion of pulverized coal etc.

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A new noncontacting method (SCB method) to measure simultaneously the time averaged local values of the characteristic parameters such as the size, velocity and passing frequency (or void fraction) of the dispersed phase, i. e., solid particles or gas bubbles in a gas-solid, gas-liquid or solid-liquid two-phase flow is proposed. Two laser beams are used as a detector. They are arranged so as to be crossed at right angles with each other with one beam being shifted at a small distance in a direction of flow. The auto-correlation of the output signal from the upstream beam and the cross-correlation between the upstream and downstream beam are calculated to determine the characteristic parameters. The SCB method was experimentally examined by using spherical particles with a known equal diameter. The characteristic parameters measured by the SCB method agreed well with those values obtained by other conventional methods.

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