On bifurcations and traction forces on an obstacle in incompressible flow

Abstract: We present a numerical study of flow-regime transitions in the two‑dimensional incompressible Navier--Stokes flow past a confined cylinder, focusing on Reynolds numbers up to 1000 within the Schäfer--Turek benchmark. For a fixed geometry, we observe a clear empirical correspondence between qualitative changes in steady boundary traction profiles, defined as the pointwise force density induced by the Cauchy stress tensor on the obstacle boundary, and bifurcations in the long‑time behavior of the unsteady flow. The observed transitions include onset of time‑periodic oscillations, secondary modifications of the oscillatory wake, emergence of pronounced asymmetry and the appearance of multiple steady solutions. These results indicate that steady traction profiles on the obstacle provide a sensitive diagnostic of critical Reynolds numbers at which qualitative changes in the global flow dynamics occur.

MathematicsPhysics

Audience: researchers in the topic

Nečas Seminar on Continuum Mechanics

Series comments: This seminar was founded on December 14, 1966.

Faculty of Mathematics and Physics, Charles University, Sokolovská 83, Prague 8. Unless stated otherwise, we will meet on Mondays at 15:40 in the lecture hall K3 (2nd floor)