Numerical investigation of heat transfer in supercritical CO2 and water turbulent flow in circular tubes

This study presents a numerical investigation of heat transfer in supercritical CO2 and water turbulent flow in a circular tube. To solve two-demonical grid systems, RSM turbulent models were used.The numerical results of this simulation were calibrated and validated the experimental data measurement. The effect of mass flow and pressure on heat transfer coefficient, flow acceleration and buoyancy parameter was considered. The numerical results have shown that increasing the mass flux causes anincrease in Reynolds number, therefore, buoyancy and flow acceleration will be decreased. In addition,an increase in pressure results in a decrease in buoyancy and flow acceleration parameters. This simulation throws some light on how the density variation in the flow of a range of supercritical temperature and pressure affect Grashof number, Reynolds number, flow acceleration, and buoyancy. A new correlation is proposed to enumerate the effect of flow acceleration and buoyancy on heat transfer phenomena in a vertical upward flow of a supercritical fluid.

کلیدواژه ها:

Supercritical heat transfer ، CFD simulation ، buoyancy effect ، flow acceleration effect ، heat-transfer deterioration