Intensification of heat transfer in chaotic modes

Abstract

This paper presents the results of numerical modeling and comparative studies of the effectiveness of diffusion, convective, and turbulent heat transfer modes in a liquid layer. Here the heat transfer physical model was used which is typical for reactors with an internal energy source. Conditions for the continuity of the fluid flow and the equations of heat transfer, analytical and simulation models of these modes are obtained based on the Navier-Stokes equation. Quantitative characteristics have been found using the simulation model, confirming the expected efficiency indicators ratios of these processes in the course of heat transfer. Convective and turbulent heat transfer processes properties are analyzed as control objects basing on the Comsol Multiphysics modeling system. Recommendations have been obtained concerning the multi-alternative algorithms synthesis for automatic control of these processes. In particular, it is advisable to use the heat flux density as a control action, whereas the liquid particle velocity dispersion should be used as an adjustable value. Corresponding control system model demonstrated the efficiency of the proposed algorithms.