Correlations between system parameters and process responses in plasma cutting

Summary form only given. Despite the wealth of work that has been done in the last decades on thermal plasmas (both industrial and academic), there still seems to be a consensus regarding the lack of basic phenomena understanding (plasma and electrode regions, external flows, etc.). The industry´s strive for a short product-to-market time necessitates a move away from trial and error style of development work due to its high financial and time cost. This is particularly true of plasma cutting systems. This work aims at combining experimental data with a simplified formulation of the process. The result is an engineering solution of the design parameters domain of a plasma cutting systems for a speedy development cycle. Attempts at predicting cutting speeds and the efficiency of the cutting process have been presented by Nemchinsky, Freton and others. In the current approach a similar more simplified path is taken in an attempt to use existing design parameters to arrive at a semi-empirical formulation that can be used to predict upcoming designs. Therefore, a number of input parameters (such as current, nozzle geometries, flows, cut material, etc.) and their responses (such as the cutting speed, kerf width, arc voltage, etc) are used in conjunction with basic knowledge of the process (such as simplified heat transfer and plasma arc properties) to arrive at a formulation of a semi-empirical transformation function. This transformation function is then used to predict the design domain (inputs and responses) of future designs. This engineering approach is limited in accuracy by the underlying assumptions used and the omissions of various complex interactions of the cutting process. Nevertheless, the results of this approach seem to give reasonable predictions for our particular need