Application of supercritical carbon dioxide jet: A parametric study using numerical simulation model

Abstract

Defining the structure of a supercritical carbon dioxide (SC–CO2) jet flow field is a critical component of establishing a theoretical basis for its application. This study investigates the influence of pressure ratio on the wave features of an SC-CO2 jet flow field using a new numerical simulation model and flow field visualization experiments. To assess the characteristics of the SC-CO2 flow field and predict the distribution of temperature and pressure, a computational model based on constant pressure specific heat capacity and thermal conductivity of SC-CO2 was established, and the user-defined function (UDF) feature available in ANSYS Fluent software was used. The results demonstrated that the temperature and pressure of the SC-CO2 jet flow field could be accurately predicted by the numerical simulation model proposed in this research, and the wave features of the flow field could be visualized by both the numerical simulation contours and the experiments. The wave features, which resulted from different pressure ratios, were found be a function of the structure of the Laval nozzle at a constant inlet pressure. The pressure ratio could be controlled by the nozzle structure and accurately describe the wave features of the SC-CO2 jet flow field. In this study, an optimal pressure ratio of 1.31 was used and the flow field structure corresponding to the maximum jet impact force could be satisfactorily described by the optimal pressure ratio.