Multi-sensing Control of Plasma Flow Systems Utilizing Super Functionalization

通过实验和理论研究，建立了利用外加磁场效应，通过注入蒸发金属和反应气体，并进一步注入细颗粒的功能等离子体流动的多传感控制系统。主要研究结果如下：(1)通过控制辐射强度和控制磁通密度，成功地建立了等离子体射流稳定的多传感控制系统。从实验上阐明了辐射强度对流量突变的恒值控制性能，进而阐明了等离子体射流动态行为对入口流量振荡的控制性能。(2)通过数值模拟，阐明了钾的施加频率和播撒比对感应耦合等离子体热流场和各种金属粉末喷射的相变的影响。(3)考虑载荷效应、相变、热物性变化、可压缩效应和复杂结构，数值分析了密集载荷下载气、颗粒和水滴的三维多相等离子射流。(4)等离子喷涂过程的数值模拟。通过开发具有较强真实感的模型，对弧灰熔化过程和弧电极系统进行了模拟。获得了提高加工效率和延长使用寿命的最佳工艺条件和等离子体枪几何形状。(5)通过超功能化技术开发了DC-RF混合等离子体系统。通过控制鞘层气体与载气的流量比，实现了等离子体火焰的延伸和均匀的温度分布。此外，还利用PIV系统对盘管区内的涡流结构进行了可视化。

The experimental and theoretical studies were carried out to establish a multi-sensing control systems for functional plasma flow by utilizing the applied magnetic effect and by seeding vaporized metal and reactive gas and further by injecting fine particles. The main results obtained here are as follows:(1) A multi-sensing control system for plasma jet stabilization was successfully established by controling the radiation intensity and by operating magnetic flux density. The constant value control performance of radiation intensity for sudden flow rate variation and further the control performance of plasma jet dynamic behavior for oscillating inlet flow rate were clarified experimentally.(2) The effects of applied frequency and seeding ratio of potassium on thermofluid field of inductivley coupled plasma and phase change of various kinds of metal powders injected were clarified by numerical simulation.(3) 3D multiphase plasma jet with carrier gas, particles and water droplet in dense loading were numerically analyzed by taking loading effect, phase change, variation of thermophysical properties, compressible effect and complex configuration into account.(4) Computational simulation for plasma spraying process, arc ash melting process and arc-electrodes system were conducted by developing strongly realistic model. The optimal operating conditions and plasma gun geometry were obtained to increase process efficiency and to extend life time.(5) DC-RF hybrid plasma systems were developed by super functionalization. The elongation of plasma flame and uniform temperature distribution were achieved by controlling the flow rate ratio of sheath gas to carrier gas. Furthermore, vortex flow structure in the coil zone was visualized by using PIV system.