Drag and heat transfer effect of grooved hydrophobic bluff bodies

This research delves into an examination of the potential reduction in friction drag within turbulent channel flow through the implementation of superhydrophobic surfaces. The focus lies on considering the effect of the hydrophobic surface as a slip boundary condition along the wall. Consequently, this newly introduced boundary condition becomes an integral part of the Large Eddy Simulation (LES) equations. The projected outcome suggests a substantial drag reduction of approximately 15% at Re = 5000-8000 and enhanced heat transfer by 20%, aligning harmoniously with the findings derived from Direct Numerical Simulation (DNS). Significantly, this discovery holds implications regarding the modification of near-wall turbulence structures through the introduction of streamwise slip velocity. Moreover, it becomes evident that the turbulence structure experiences a discernible transformation when the slip length exceeds a specific threshold value.