1 - Introduction

Abstract

This chapter provides an introduction to fluid-particle flow. The use of particles as fluid tracers calls for a knowledge of single particle behaviors only. Theoretical formulation of multiphase flow in general and fluid-particle flow in particular has progressed along two paths. The one based on analogy to kinetic theory calls for experimental determination of details of particle-fluid and particle-particle interactions. The one through an extension of continuum mechanics needs an input of transport parameter, which has to be determined by data of local instantaneous properties of particle clouds. Continuum mechanics based on averages of flow properties cover the whole range of dense and dilute suspensions because interactions are inclusive in the transport properties. The kinetic approach tends to be successful in treating dilute suspensions. Measurements of local instantaneous velocity, density, and mass flow of phases of a gas-solid suspension are needed in determining transport properties, validating theoretical predictions, and formulating design procedures. This chapter presents a common concern of probe dimension or measuring volume in relation to particle size or spacing in the evaluation of measured data. The chapter mentions briefly on the following chapters including topics such as instrumentation and devices, different approach toward averaging and direct measurement of local density and others.