A method for testing drag-reduction on riblet surfaces based on the Spalding formula

Abstract

This paper presents a method based on the Spalding formula for testing drag-reduction on riblet surfaces. Its advantage lies in that it is more convenient and yields more precise data compared with testing methods using instruments such as a scale. With this method, data is obtained from the velocity distribution within the inner layer, nearest the riblet surface. Precision of measurement of the velocity distribution is the key factor affecting the precision of the testing.

Keywords

Spalding formula / riblet surface / drag-reduction testing