The significance of the buffer zone of boundary layer on convective heat transfer to a vertical turbulent flow of a supercritical fluid

Turbulent heat transfer characteristics of supercritical n ‐decane in a vertical tube under various operating pressures

“…It can be seen that the bulk temperatures of the fluid at different operating pressures are close to each other and this phenomenon agrees well with the findings in Hua et al Particularly for the operating pressure of 3 MPa, the inner wall temperature is close to 800 K, and it is above the pseudo‐critical temperature 648.2 K. The bulk temperature of the fluid is 610.1 K, and it is less than the pseudo‐critical temperature 648.2 K when the phenomenon of heat transfer deterioration occurs. These characteristics agree well with the description in Bazargan and Mohseni …”

“…Correspondingly, the shear stress between the flow layers is reduced, and the turbulent kinetic energy is also decreased. Consequently, the heat transfer is compromised, and further, the phenomenon of heat transfer deterioration appears . For the operating pressures of 4 and 5 MPa, there is no obvious M‐type velocity distribution and the velocity profile is the typical one for forced convective distribution.…”

Numerical investigation of heat transfer characteristics and flow resistance of kerosene RP-3 under supercritical pressure

“…The existing investigations into supercritical fluids are mainly focused on water and carbon dioxide [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Mokry et al [8] confirmed that there were three heat-transfer regimes for forced-convective heat transfer to water flowing inside tubes at supercritical pressures: namely, the normal heat-transfer regime, the deteriorated heat-transfer regime and the improved heat-transfer regime.…”

“…Kim et al [9] found that heat transfer deterioration occurred when q > 0.2G.2.0 regardless of the cross-sectional shapes of tubes. Bazargan and Mohseni [10] numerically studied the significance of the buffer zone in the boundary layer by using carbon dioxide in a round tube at supercritical pressure. They concluded that heat transfer deterioration was due to the turbulence reduction and flow laminarization.…”

Buoyancy induced heat transfer deterioration in vertical concentric and eccentric annuli

“…As this phenomenon is closely related to the mechanism by which turbulence energy is produced, the right choice of turbulence model is crucial here. A widespread choice for this problem has been low Reynolds variations of k-e model [9][10][11]. However more careful studies have recently revealed that this class of two-equation models may not be as loyal to the physics of problem as their results suggest.…”