Calculation of gas flow in ducts of gas-jet systems

In electric power plants of various types working medium moves in ducts of different forms, sizes and functions. In many essential cases power plants include system of ducts with stream confluence and separation. Usually power plants operate in stationary mode most of the time, but in some systems work processes run during small periods of time and are followed by significant changes in speed, pressure and temperature along the duct as well as in time.Mathematical model of such ducts include unsteady-state partial equations governing the laws of mass, momentum and energy conservation. Solution of equation system is provided by extensive use of finite-difference method. This boundary problem is nonlinear, thus numerical methods are used for solution.The paper presents numerical method for calculation of processes of hydrodynamics and heat exchange inthe ducts of energetic power plants with stream confluence and separation on the basis of finite-difference method and algorithm of orthogonal pass of boundary problem solution.Developed algorithm has high computational efficiency and allows calculating high-intensity operation modes of duct with compressible working medium as well as incompressible one, with heat exchange with ductwalls or adiabatic operation conditions. Numerical method allows calculating processes both in particular ducts and duct system under consistent approach.