Formation of the Supersonic Heterogeneous Streams in the Gasdynamic Accelerators With Great Elongation

Abstract

The present article describes results of the experimental and theoretical investigation of gas dynamics and heat exchange in the course of a supersonic flow of the gas-powder mixture within the axially symmetric gas-dynamic accelerators, which have small critical cross-sections (dcritical from 1 to 3 mm) and substantial elongation (L/dcritical from 70 to 200). The necessity of performance of such investigations was determined by two aspects. The first is the development of the innovative technologies with the purpose of formation of the heat-resistant coatings and other coatings with various functions and necessary properties (formation of such coatings with the help of supersonic heterogeneous streams). The second is the creation of the supersonic heterogeneous streams, which are required for the development of experimental investigations of processes of the erosive and corrosive wear of structural components of the high-speed air vehicles, which conduct flights in atmospheric anomalies (rain clouded sky and dust-in-air conditions). This study describes the entire cycle of the experimental investigations, which were performed with the purpose of construction of the more reliable mathematical model of flow of the nonisentropic heterogeneous streams in the gas-dynamic accelerators with great elongation. The viscous gas flow parameters were calculated using the classical model of a flat boundary layer. The value of the characteristics of the carrier gas flow, the dispersion of particles and their material for accelerating particles in a heterogeneous flow were found out. The study showed that the design of gasdynamic micro accelerators must be carried out taking into account the increase in the thickness of the boundary layer along the walls of the particle accelerator. In addition, this article presents a more detailed description of gas dynamics of flow and heat exchange of the heterogeneous mixtures within supersonic gasdynamic accelerators with mass concentration of the powder particles ("К-phase") in the stream up to 15%.