Simulation of low-temperature operation mode gas generator

Low-temperature gas generator (LTGG) for producing gas with a temperature of 350... 450 K. It consists of two main parts - a combustion chamber with a charge of solid propellant and cooling chamber with granules of the solid coolant. The products of combustion of solid propellant have a high temperature that does not allow to use them in a variety of technical devices. Cooling gas is the result of its interaction with the solid granules cooler on the thermal decomposition of which consumes part of the internal energy of the gas. To describe the processes of heat and mass transfer in LTGG developed a mathematical model based on the one-dimensional equations of continuity, momentum, energy and mass balance of the components of the gas mixture. The gas mixture is composed of products of combustion of solid propellant, degradation products and the air cooler. The mathematical model takes into account the ignition and combustion of the fuel within the gas mixture in LTGG, heat exchange with the structural elements LTGG and kinetics of degradation of pellets cooler. To implement the mathematical model developed numerical method for solving the boundary value problem based on the finite difference method. The system of equations is approximated by implicit difference schemes. For the solution of nonlinear differential equations applied Newton's method. A boundary value problem was solved orthogonal factorization. The calculation results are compared with experimental data. The influence of constructive and regime parameters on the change in temperature, pressure, flow, speed expansion cooler.