ABSTRACT
Particulate pollutants carried by the atmosphere and sediment carried by rivers were among the fi rst multiphase fl ows to receive serious study. Such fl ows were rather dilute suspensions and were modeled as such. Th e analysis of dilute particulate transport was given a major boost by NASA and the Air Force’s interests in the fl ow of aluminum oxide particles in solid rocket motors and their plumes. Since the aerospace industry pioneered
the use of computers for solving transport phenomena problems because laboratory experiments could not duplicate space conditions, more reliance was forced on numerical simulation. Th e process industries utilized laboratory experiments, which simplifi ed the fl ow phenomena as much as possible to create phase interfaces for which the multitude of chemical systems could be studied. Interphase transport was measured primarily in falling fi lm devices for which the fl uid velocity fi elds were assumed to be known. Practical processes were analyzed by empirical extrapolation of such test data. Later, fl uidized bed technology was utilized for reactor design, which forced the process industries into exploring the dense suspension fl ows involved in such devices. Environmental scientists had the full-scale transport processes at hand and consequently spent their eff orts on measuring and collecting experimental data. Once again such data were interpreted by empirical correlations and dimensional analysis. Numerical simulations of the large-scale fl ows involved had to await the development of more computer power and of innovative averaging techniques.
