Modelling the Plasma Jet in Multi-Arc Plasma Spraying
Modelling the Plasma Jet in Multi-Arc Plasma Spraying
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DOI：
10.1007/s11666-016-0438-0
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发表时间：
2016-07
影响因子：
3.1
通讯作者：
K. Bobzin;M. Öte;J. Schein;S. Zimmermann;K. Möhwald;C. Lummer
中科院分区：
文献类型：
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作者：
K. Bobzin;M. Öte;J. Schein;S. Zimmermann;K. Möhwald;C. Lummer
大气等离子喷涂过程中，等离子体射流与粉末颗粒之间的冲量和热能传递决定了粉末颗粒的飞行特性。因此，影响等离子体喷涂涂层质量的重要因素之一是等离子体射流中等离子体气体温度和速度的分布。传统单弧等离子喷涂系统产生的等离子射流及其与粉末颗粒的相互作用是深入研究的主题。然而，这还不适用于通过多弧等离子喷涂系统产生的等离子射流。在这项研究中，已经开发了一个数值模型，这是指定处理的等离子体射流的流动特性，通过三阴极喷涂系统。上游流动条件，这是使用先验进行等离子体发生器模拟计算，已耦合到等离子体射流模拟。分析了相关数值假设的意义和模型的特点。重点放在湍流和扩散/分层模型。的预测能力的模型进行了一个关键的评估，通过比较的数值结果，通过发射光谱计算机断层扫描确定的实验结果。很明显，数值模型表现出良好的精度为他们的预期用途。
Particle in-flight characteristics in atmospheric plasma spraying process are determined by impulse and heat energy transferred between the plasma jet and injected powder particles. One of the important factors for the quality of the plasma-sprayed coatings is thus the distribution of plasma gas temperatures and velocities in plasma jet. Plasma jets generated by conventional single-arc plasma spraying systems and their interaction with powder particles were subject matter of intensive research. However, this does not apply to plasma jets generated by means of multi-arc plasma spraying systems yet. In this study, a numerical model has been developed which is designated to dealing with the flow characteristics of the plasma jet generated by means of a three-cathode spraying system. The upstream flow conditions, which were calculated using a priori conducted plasma generator simulations, have been coupled to the plasma jet simulations. The significances of the relevant numerical assumptions and aspects of the models are analyzed. The focus is placed on to the turbulence and diffusion/demixing modelling. A critical evaluation of the prediction power of the models is conducted by comparing the numerical results to the experimental results determined by means of emission spectroscopic computed tomography. It is evident that the numerical models exhibit a good accuracy for their intended use.