The effects of thermal properties on the interphase drag of supercritical water-particle flow

The drag of particle clusters is important for the investigation of fluidized beds, but there is no accurate correlation available. The effects of nonlinear physical properties on the drag of particle clusters in supercritical water (SCW) fluidized beds cannot be overlooked either. This work conducts a simulation investigation on the interphase drag of SCW-particle flow. The results reveal that an increase in density leads to a decrease in the drag coefficient C_d. This results in a positive correlation between the drag coefficient and particle temperature. The effects of Reynolds number (Re) and void fraction (ε) on the density distribution further influence the normalized drag coefficient C. The distributions of dimensionless velocity and kinetic energy indicate that the conversion rate of pressure potential energy to kinetic energy in SCW is lower than that in constant property flow (CPF). The distributions of C_d and C of sub-particles show that downstream particles are most influenced by variations in density under different conditions. A model for the effects of nonlinear physical properties is established based on the C. Analysis of the results from CPF reveals that the exponent β in this work is primarily a function of ε. A correlation between the exponent β and ε is established. A drag coefficient model for particle flow in SCW is developed through the coupling of multiple models.