The hydrodynamic sTabiliTy of a fluid-parTicle flow: insTabiliTies in gas-fluidized beds

179 The last few lectures of an undergraduate class in fluid mechanics offer instructors an opportunity to teach students some advanced topics that go beyond the traditional course material.[1] Fluid-particle flows, where both the fluid and particle are in motion, are prevalent in many industries including the chemical, materials, and energy industries.[2] In the pharmaceutical and biotechnology industries, which are hiring unprecedented numbers of chemical engineers, nearly all manufacturing facilities involve multiple processing steps that include fluid-particle flows. In spite of the industrial importance of fluid-particle flows, they are rarely covered in any depth in a fluid mechanics course.[3] Moreover, it is difficult to find examples of fluid-particle flows where undergraduates have the necessary background to handle the equations and analysis that is necessary if more than a survey of the material is to be achieved.