INVESTIGATION OF THE MICROPHYSICAL CHARACTERISTICS OF AEROSOLS BY THE METHOD OF ELECTRODYNAMIC SUSPENSION OF PARTICLES. 1. STRUCTURE OF THE EDS AND DETERMINATION OF THE DRAG FORCE OF MICROPARTICLESV. A. Runkov, P. E. Suetin, and S. A. Beresnev UDC 531.75+541.18 This paper describes the structure of an electrodynamic suspension (EDS) with flat electrodes for investigating a complex of characteristics of charged microparticles and the surrounding gas. A linear theory of oscillatory motion of a microparticle in the EDS volume has been developed and analytical expressions for the oscillation amplitude and the center of oscillation of a particle depending on the electrode voltage value have been obtained. The stability boundary of motion of particles of various substances for the EDS of the given configuration has been determined theoretically. For the first time the dynamic behavior of aerosols in the EDS in a wide range of change in the surrounding gas pressure (Knudsen number) has been studied experimentally, in particular, data for the drag force of a particle have been obtained. Comparison between the experimental and theoretical data has been made. Urals State University, Ekaterinburg, Russia; email: Sergey.Beresnev@usu.ru. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 76, No. 2, pp. 3-8, March-April, 2003. Original article submitted October 16, 2002.