Numerical simulation of optical breakdown in a liquid droplet induced by a laser pulse

Abstract

Please cite this article as: P.V. Bulat, O.P. Minin, K.N. Volkov, Numerical simulation of optical breakdown in a liquid droplet induced by a laser pulse, Acta Astronautica (2017), AbstractModelling and simulation of interaction of laser pulse with individual liquid droplets are of crucial importance in terms of development and code coupling for simulation of laser propulsion and detonation in gas-droplet systems. These applications are challenging and complex for many reasons, one among them is the disparate time and length scales that are required to resolve for an accurate physical representation of the problem. The injection of liquid droplets with low evaporation temperature causes optical breakdown on the individual droplet and leads to a drop of the minimum pulse energy of detonation in the gas-droplet mixture. The mathematical models of various stages of the optical breakdown on individual droplet and numerical methodology for computer modelling of the laser-induced breakdown are developed. Sub-models of optical breakdown on liquid droplet include droplet heating to boiling temperature, its evaporation and formation of vapor aureole around the droplet, ionization of vapor aureole and development of electron avalanche, appearance of microplasma spots and their expansion, propagation of shock wave inside the droplet and in the surrounding gas. The threshold intensity of optical breakdown on individual water droplet and its dependence on droplet radius, location of droplet, total energy and radius of laser pulse are studied.

Improved calculation of the Mie solution and the geometrical optics approximation for large droplets

“…The assertion about the possibility to ignite tiny fires in droplets due to internal energy focusing can be met in [53,54]. The computer simulations of the phenomenon called optical breakdown have recently been carried out [55,56]. An attention was paid to the super-resonance of Fano for the generation of electric and magnetic fields at the poles of a spherical particle [57][58][59].…”

Воспламенение Топливной Смеси С Помощью Многоточечного Импульсного Искрового Разряда При Различных Начальных Условиях

“…Известные устройства для зажигания топливных смесей различаются видом воспламеняющих физических средств [2,3]. Для поджигания топливных смесей находят применение электрические разряды разного типа [4][5][6], импульсное лазерное излучение [7][8][9], микроволновый СВЧ-разряд [10-13], воздушные плазмотроны [14]. В газодинамическом принципе зажигания топлива реакция горения инициируется нагревом топливной смеси на поверхности полого газодинамического резонатора, разогрев которого осуществляется за счет собственной внутренней энергии сжатого газа при возбуждении акустических колебаний.…”