Numerical Prediction of Heat Transfer for Supercritical Carbon Dioxide in Horizontal Circular Tubes

Due to their high specific heat, low viscosity, and good diffusivity, supercritical fluids have the potential to be ideal coolants. However, understanding the heat transfer for fluids under supercritical conditions has been a challenge. To understand the peculiar heat transfer characteristics, a wide range of experiments with different ranges of parameters and geometrical configurations has been conducted. The generated experimental data can be used as a reference to expand and assess the prediction capabilities of computational fluid dynamics (CFD) models under supercritical conditions. Out of these models, Reynolds-Averaged Navier-Stokes (RANS) modeling approach is the most widely used one and requires less computational power compared to other modeling approaches. This work aims to study the heat transfer characteristics of supercritical Carbon Dioxide (SCO2). The current work is focused on the numerical modeling of SCO2 in horizontal tubes using different RANS model. Various flow conditions are modeled to study the impact on the heat transfer coefficient. A large temperature variation is also expected in some conditions due to stratification. To validate the results, an extensive comparative study with experimental data has been performed.