A numerical model for simulating air and nitrogen inductively coupled plasmas (ICPs) was developed considering thermochemical nonequilibrium and the third-order electron transport properties. A modified far-field electromagnetic model was introduced and tightly coupled with the flow field equations to describe the Joule heating and inductive discharge phenomena. In total, 11 species and 49 chemical reactions of air, which include 5 species and 8 chemical reactions of nitrogen, were employed to model the chemical reaction process. The internal energy transfers among translational, vibrational, rotational, and electronic energy modes of chemical species were taken into account to study thermal nonequilibrium effects. The low-Reynolds number Abe-Kondoh-Nagano k-ε turbulence model was employed to consider the turbulent heat transfer. In this study, the fundamental characteristics of an ICP flow, such as the weak ionization, high temperature but low velocity in the torch, and wide area of the plasma plume, were reproduced by the developed numerical model. The flow field differences between the air and nitrogen ICP flows inside the 10-kW ICP wind tunnel were made clear. The interactions between the electromagnetic and flow fields were also revealed for an inductive discharge.

Numerical simulations of 10 kW and 110 kW inductively coupled plasma (ICP) wind tunnels were carried out to study physical properties of the flow inside the ICP torch and vacuum chamber with air as the working gas. Two-dimensional compressible axisymmetric Navier-Stokes (N-S) equations that took into account 11 species and 49 chemical reactions of air, were solved. A heat source model was used to describe the heating phenomenon instead of solving the electromagnetic equations. In the vacuum chamber, a four-temperature model was coupled with N-S equations. Numerical results for the 10 kW ICP wind tunnel are presented and discussed in detail as a representative case. It was found that the plasma flow in the vacuum chamber tended to be in local thermochemical equilibrium. To study the influence of operation conditions on the flow field, simulations were carried out for different chamber pressures and/or input powers. The computational results for the above two ICP wind tunnels were compared with corresponding experimental data. The computational and experimental results agree well, therefore the flow fields of ICP wind tunnels can be clearly understood.

This paper aims to study the three-dimensional transient flow-field properties of the gas-liquid dual-fluid atomizer, which has high flow capacity and low energy consumption. The two-phase atomization process of air and water, the negative pressure gradient near the porous medium and the recirculation flow inside the atomizer were numerically simulated and analyzed. Primarily, the influence of the air flow velocity on the water flow velocity at the water inlet was numerically studied. Furthermore, it was proven that the simulated results agree well with the experimental data. Thereafter, the variations in the inlet's water flow velocity and vortex current zone size were studied in detail with changes in the orifice diameter and outlet pipe length. The results indicated that the water absorption improves as the air flow velocity increases. There is a suitable orifice diameter to maximize water flow and maximize the secondary atomization. The water flow velocity becomes larger and the secondary atomization improves as the length of the outlet pipe increases. The larger the vortex region, the smaller the droplet size. This study could provide theoretical data and guidance for the optimization design of dual-fluid atomizers.

Experimental and analytical studies of CO2 absorption performance are carried out in a gas-liquid two-phase flow atomizer on the basis of a gas diffusion model. The gas-liquid two-phase flow atomizer with high spray efficiency and low power consumption has been applied to CO2 absorption. Experiments for the CO2 absorption were conducted in an isolated room and the results showed that, the mist sprayed by the improved atomizer can effectively reduce the CO2 concentration. Furthermore, a CO2 diffusion model was developed to predict the absorption process. This model was validated through a comparison between calculation and experiment. Comparison results showed that the proposed model could predict the time-variations of CO2 concentration well in the test room.

This paper studied the flow field properties of the 10 kW inductively coupled plasma wind tunnel (ICPWT). The results can be used for the development of the thermal material protection material for re-entry aerospace vehicles. In this paper, the ICP flow under different input powers was numerically simulated, and the flow-field characteristics in the ICP torch under different operating parameters were obtained. The results showed that when the input power is the typical working power i.e. 10 kW, the electron number density in the plasma torch reaches a maximum of 3.23×1021 1/m3, and the electron temperature is also up to 0.99 eV. Besides, the velocity in the plasma torch reaches a maximum of 34.9 m/s, and the translational temperature also reaches a maximum value of 8740 K.