Microfiber Coating for Flow Control over a Blunt Surface

Coatings

Hirotaka Sakaue¹  Mitsugu Hasegawa¹ 

[1] Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA;

关键词: microfiber;    electrostatic flocking;    passive flow control;    drag reduction;   

DOI  :  10.3390/coatings9100664

来源: DOAJ

【 摘 要 】

A microfiber coating having a hair-like structure is investigated as a passive flow control device of a bluff body. The effect of microfiber length is experimentally studied to understand the impact of the coating on drag on a cylinder. A series of microfiber coatings with different lengths are fabricated using flocking technology and applied to various locations over the cylinder surface under the constant Reynolds number of 6.1 × 10⁴ based on the diameter of the cylinder. It is found that the length and the location both play important roles in the drag reduction. Two types of drag reduction can be seen: (1) when the relative length of the microfiber, k/D, is less than 1.8%, and the coating is applied before flow separates over the cylinder; and (2) k/D is over 3.3%, and the coating is applied after the flow separation location on the cylinder. The maximum drag reduction for the former type is 59% compared to that from the cylinder without the microfiber coating. For the latter type, the maximum drag reduction is 27%.

【 授权许可】

Unknown