Heat transfer to supercritical water in circular tubes with circumferentially non-uniform heating

Comparison between heat transfer to supercritical water in a smooth tube and in an internally ribbed tube

“…Both the dramatic fluid property change and swirling flow induced by internal ribs need to be carefully considered. An exhaustive literature review regarding to numerical studies on heat transfer to supercritical fluids has been done in the authors' previous work [35]. It is found that among various RANS model, the V2F [36,37] and Shear-Stress Transport k-x (SST) model [38][39][40] seem to show better accuracies relative to other models such as low-Reynolds k-e models.…”

Effects of rib geometries and property variations on heat transfer to supercritical water in internally ribbed tubes

“…Transport equations for mass, momentum, energy, turbulent kinetic energy and specific turbulent dissipation rate are solved and they are the same with those in the authors' previous work [38]. Calculating geometries are vertical internally ribbed tubes as presented in Fig.…”

“…Flows of both fluids through smooth tubes, in which successful prediction has been obtained in Ref. [38] using the Shear-Stress Transport k-u model, are also studied as control (reference) tests. Fig.…”

“…The mesh scheme is similar to that in Ref. [38]. Structured hexahedral meshes were generated using the commercial preprocessing software ICEM for all the cases studied.…”

“…Discretization scheme, initialization method and convergence criteria were the same with those in Ref. [38]. Temperature-dependent water properties derived from IAPWS-IF97 [39] were used in the simulation, and a constant pressure was used for thermophysical properties since despite the existence of internal ribs, pressure drop along the tube can still be ignored when compared with operating pressure [13,16,40].…”