Title: Investigation of the flow topology evolution between two tandem cylinders using a discontinuous Galerkin method

Authors: Xiangjun Shan; Fangjin Sun

Addresses: School of Mechanics and Engineering, Liaoning Technical University, Fuxin, 123000, China ' School of Mechanics and Engineering, Liaoning Technical University, Fuxin, 123000, China

Abstract: A high-order discontinuous Galerkin method is used to study the transient behaviour of the flow between two cylinders in a tandem arrangement. A low Reynolds number of 200 and a pitch ratio of 3.7 are particularly employed, where a gradual transition process of the flow from reattachment flow to co-shedding flow is observed. The evolution of the flow topology in the gap between two cylinders, the transient surface pressure and the phase lag of the lift signal from reattachment flow to co-shedding flow are investigated, and the physical mechanism responsible for the flow transition is also discussed. The results show that the rolling up of the separated shear layer between two cylinders is closely related to the development of the gap flow. The gap flow is a unidirectional flow in the reattachment regime and gradually develops into a 'horseshoe-shaped' bidirectional flow when the flow transitions to the co-shedding regime.

Keywords: discontinuous Galerkin method; higher-order accuracy; tandem cylinders; low Reynolds number; transient characteristics; incompressible flow.

DOI: 10.1504/PCFD.2024.135634

Progress in Computational Fluid Dynamics, An International Journal, 2024 Vol.24 No.1, pp.29 - 41

Received: 25 Jun 2021
Received in revised form: 26 Jul 2022
Accepted: 24 Oct 2022
Published online: 20 Dec 2023 *