Properly-Designed Rough Surfaces can Reduce Drag: Study

Majorly, objects moving through water are smooth. But as a research, a study carried out by a group of researchers from UCLA, bumpiness can be better in certain cases.
Prof. John Kim from the mechanical and aerospace engineering department at UCLA said that some rough surfaces are able to reduce skin-friction drag. Before, conducting the study, they used to believe contrary to the same.
In their study, fluid movement was monitored between two surfaces coated with small ridge. The study researchers found very astonishing results that the rough surface was able to reduce drag in bumpy conditions generated by the frictions of moving water.
Studies have been taken on the topic earlier as well, but not much success has been achieved. In the current study, the study researchers have modeled a superhydrophobic surface. The surface was coated with ridges and was positioned in the direction of water flow.
Laminar and turbulent flows, bother were modeled. To their surprise, the drag reduction was found to be greater in turbulent conditions. The revelation of the same has been published in the American Institute of Physics.
Prof. Kim said about properly-designed rough surfaces, "It could lead to significant energy savings and reduction of greenhouse gas emissions".