Document Type

Article

Publication Date

2-16-2026

Abstract

The surface pressure distribution over a circular cylinder with a small, full-span, triangular bump is examined. The geometry of the bump is an isosceles triangle, the height of which is varied from 1.33 % to 5.33 % of the diameter of the cylinder and positioned between 60° and 120°. The Reynolds number (Re=V∞ D/ν, where V∞ is the velocity of the freestream, D is the diameter of the cylinder and ν is the kinematic viscosity) is varied between 1.1×105 and 1.8×105. The lift and drag are estimated through the surface integral of pressure over the cylinder. The results show that the smallest bump acts as a trip for the lower Re and orientations before 70°, leading to a separation farther upstream than in the case of no bump. For larger bumps, Re and orientation angles, the bump acts as a spoiler and fully separates the boundary layer at the bump. In addition, the surface pressure upstream of the bump is strongly dependent on the bump position. The lift is highest for bump position less than 90° and decreases significantly with increasing bump location angle. The drag is less sensitive to the position of the bump. These findings have implications for predicting the forces on bluff bodies due to small asymmetric surface geometry features and extension to applications such as atmospheric flow over topography.

Department

Integrated Engineering

College

Science, Engineering and Technology

Online ISSN

2633-4259

Publication Title

Flow

DOI

10.1017/flo.2026.10042

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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