ANNULAR MIXING SECTION EFFECTS ON HYDROGEN PEROXIDE-AIR TWO-PHASE FLOW INSIDE A MINI-CHANNEL

摘要

Hydrogen peroxide is called a green propellant in rocketry and is a monopropellant. Recent advances in the development of micro-thrusters for mini/micro-satellites require a thorough knowledge of the reactions occurring in these types of thrust chambers. A monopropellant such as hydrogen peroxide is preferred in micro-thrusters because the chemical is self-decomposable or undergoes catalytic decomposition. The catalytic decomposition of hydrogen peroxide when using a platinum or silver catalyst results in two-phase flow in mini/micro-channel thrusters. Also, the introduction of air in such reactions will increase turbulence, enhancing the reaction. The present work is an attempt to understand the phenomena of slug formation in an annular mixing section. Various two-phase flow patterns of a hydrogen peroxide and air mixture is numerically simulated with ANSYS Fluent 12.1 using the volume of fluids method. A tube of 100 mm length and 2.50 mm diameter is used in the experiments. The bubble and slug-bubble flow patterns formed using four different concentrations (0%, 6%, 30%, and 70%) of hydrogen peroxide are analyzed. To validate the numerical results, experimental flow visualization of the 6% hydrogen peroxide concentration is analyzed with image processing techniques. The results are in good agreement and the effect of the core annular mixing section on the formation of the slug-bubble regime is detailed.