(61a) Experimental and Modeling Investigation of Sand Dune and Sand Bed Transition
The experimental data is acquired in a 10 cm (4 in.) ID pipe, utilizing air as the gas phase, water-PAC, and water as the liquid phases. Effect of particle size (glass beads) is measured by using particles of specific gravity of 2.65 and three different sizes, namely, 45-90, 125-250 and 425-600 µm, with concentrations up to 10,000 PPM. The effect of superficial velocities as well as viscosity on the sand bed flow patterns are also measured. The experimental data show that formation of dunes and bed is strongly dependent on particle concentration, particle size, phase velocities and liquid viscosities.
A mechanistic modeling is developed to predict the transition between separated dune and stationary bed, sand bed flow regimes. The model developed includes rolling and saltation mechanisms for particles located between two sand piles. If these particles are salted or rolled up on a pile, transition to separated dunes occur, otherwise, stationary bed exits along the pipe. The comparison between the model and experimental data confirms an averaged uncertainty less than 20% for all conditions.
This paper has an Extended Abstract file available; you must purchase the conference proceedings to access it.
Do you already own this?
Log In for instructions on accessing this content.
|AIChE Graduate Student Members||Free|
|AIChE Undergraduate Student Members||Free|