Study on the micro-dimpled surface in terms of drag performance

Abstract

The main objective of the present study is to assess the feasibility of a micro-dimpled surface on the drag performance. Flat plates and 3-D cylindrical bodies are prepared to study the effectiveness of the micro-dimpled surface. Micro-sized dimples are carved into the metal surface directly using an ultrasonic nano-crystal surface modification method. The turbulent boundary layer over the dimpled-surface and the wake behind the trailing edge of the flat plates are measured by flow measurement techniques and revealed the augmentation of axial momentum in the boundary layer. The dimpled surface with submicron-scaled roughness affected the hydrophobicity of the surface. It was eventually found that the dimple manufacturing provides better surface finish which causes the reduction in drag force. (C) 2015 Elsevier Inc. All rights reserved.