Heat transfer coefficient for flat and ribbed surfaces with interrupted heating

The heat dissipation due to flat and ribbed surfaces is extensively studied, mainly with uniform temperature or uniform heat flux conditions. It is known that when the boundary layer is interrupted, the heat transfer coefficient can increase significantly. In view of the increase of heat flux in devices and applications, a computational study of interrupted heating with flat and ribbed surfaces is conducted. The findings of the study can provide useful insight into enhancing the forced convection cooling by air in various applications. Computations were conducted using the commercial computational fluid dynamics code FLUENT. The modelling parameters were selected to correspond to an experimental study being conducted at UC Davis. The renormalised group (RNG) k-ε (thermal conductivity-kinetic energy dissipation rate) turbulence model with nonequilibrium wall functions is used to model the turbulent flows. The computational results are verified with experimental data from UC Davis. In addition, the effects of using different turbulence models provided by FLUENT are also examined