Influence of surface roughness on the cross-flow around a circular cylinder

TLDR

The study investigates how surface roughness affects cross‑flow around a circular cylinder. Experiments were performed in a high‑pressure wind tunnel at Reynolds numbers up to 3 × 10⁶, measuring local pressure and skin‑friction to compute drag, friction, transition, and separation characteristics as functions of Reynolds number and roughness.

Abstract

The influence of surface roughness on the cross-flow around a circular cylinder is the subject of the present experimental work. The investigations were carried out in a high-pressure wind tunnel, thus high Reynolds numbers up to Re = 3 × 10 6 could be obtained. Local pressure and skin friction distributions were measured. These quantities were evaluated to determine the total drag coefficient and the percentage of friction as functions of Reynolds number and roughness parameter. In addition the local skin friction distribution yields the angular position of boundary-layer transition from laminar to turbulent flow and the location of boundary-layer separation.