The effect of swirl velocity on ICP torch simulation

Abstract

In this paper numerical simulation is performed to investigate the effects of swirl velocity on the characteristics of argon discharges in 2D axi-symmetric inductively coupled plasma (ICP) torch working at atmospheric pressure. Simulations were carried out using an indigenously developed CFD code for the standard RF-ICP torch geometry under the assumption of local thermodynamic assumption (LTE), steady and laminar flow. The argon plasma is simulated at oscillator frequency of 3.0 MHz with coil current 150 Amp. Study has been done for different swirl velocities of plasma and sheath gas. In this paper, we consider the swirl of sheath and plasma gas and reverse swirl. In reverse swirl, at the inlet, swirl is given to plasma gas in one direction and sheath gas in the opposite directions. The swirl effect has been adjudged from thermal energy transport point of view. It has been found that swirl of sheath gas increases the wall heat loss and decreases the axial temperature towards the outlet of the torch. The increased heat transfer rate along the periphery of plasma core, due to swirl velocity, increases the stability of plasma core.