Bifurcation in particle granular temperature of monodispersed glass spheres at the Geldart A/B transition

We summarize and discuss new experimental data on the granular temperature, as a function of gas flow for monodispersed glass spheres, whose diameters, D, span the Geldart B/A transition at D approximate to 120 mu m, fluidized in helium or argon gas. We observe a bifurcation in the granular temperature across this transition which is sufficient to stabilize the uniform fluidized state of Geldart A glass spheres according to simple first order, 1-D models of the stability. We compare the experimental data to new first principles statistical models of the dependence of the granular temperature on gas flow and sphere diameter due to Buyevich.