Flat background probe in the mode of the continuous environment
Mathematics. Physics. Mechanics
Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
Consider a flat wall surface probe in the form of an elongated rectangle, located on a streamlined dense plasma surface. The problem is non-stationary two-dimensional, multi-parameter if the flow velocity is parallel to this surface and perpendicular to the long side of the rectangle.
Mathematical model of the problem includes the equation of continuity for ions and electrons and the Poisson equation for the self-consistent electric field. Total speed of charged particles vector consists of three components: convective, diffusive and a component that is associated with mobility. Convective component is determined from the solution of gas dynamic part of the problem and is considered a given.
Numerical model of the problem is based on the method of successive iterations in time. In particular, the continuity equation is solved by Davydov method of large particles, and the Poisson equation — by spectral methods.
Sets of current-voltage characteristics (CVC), sufficient for practice within limits of geometrical dimensions of the probe and values of directed plasma flow velocity, were obtained in numerical experiments. This set of CVC allows you to refine the results of processing the characteristics of probes installed on the surface of hypersonic aircraft (HA), as well as in plasma jets flowing out of technological plasmatrons in various applications (plasma chemistry, plasma spraying, plasma processing of surfaces, plasma electronics and etc).
In addition to probe characteristics profiles, the self-consistent electric fields, the concentrations of ions and electrons, evolutionary curves for streams of charged particles upon a plane probe and information about the role of nonlinear finite and edge effects are described in article. This information is necessary for analysis of heat, charge, mass flows and momentum flux from plasma upon the surface of HA.
Keywords:electric probe, voltage-current characteristic, flat wall surface probe, continuity equation, Poisson equation, finite effect, edge effect
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