IDDES simulation of side-by-side cylinder flow with different turbulence intensities at subcritical Reynolds number

In the present study, the OpenFOAM single-flow solver based on the Improved Delayed Detached Eddy Simulation (IDDES) is used to simulate the side-by-side cylinder flow at a subcritical Reynolds number Re = 3900 under different turbulence intensities ( I ) and space ratios ( T / D , where T is the center-to-center distance between cylinders and D is the diameter). We analyzed the time-averaged flow characteristics, transient flow characteristics, and hydrodynamic parameter distributions of the side-by-side cylinder flow under different space ratios and turbulence intensities. Results show that (1) When 1.1 ≤ T / D ≤ 2.5 , the increase in turbulence intensity changes the size of the time-averaged wake region and the length of the shear layer behind the cylinders, but has no effect on the shape of the distribution contour. (2) As the I increases, the peak velocity position in the gap side between the two cylinders moves away from the cylinder surfaces. The curvature of the velocity distribution curve decreases, and the curve tends toward symmetry about the x -axis. (3) The increase in turbulence intensity changes the law of variation in the time history of drag coefficients and lift coefficients for side-by-side cylinders, and I is one of the main reasons for the random flip-flop of gap flow, resulting in bistable characteristics. (4) The increase in I changes the magnitude and distribution pattern of the time and space averaged pressure coefficient on the cylinder surface, and delays flow separation on both sides of the side-by-side cylinders. However, it does not affect the time-averaged pressure stagnation angle. • Numerical simulations of side-by-side cylinder flow at Re = 3900 were performed under different turbulence intensities ( I ). • The increase in I is one of the main reasons for the random flip-flop of gap flow, resulting in bistable characteristics. • As I rise, gap-side peak flow velocity moves off the cylinder, with the velocity distribution curve curvature decreasing. • The increase in I delays flow separation on both sides of the side-by-side cylinders. • The influence of I on drag, lift, pressure coefficient, and other hydrodynamic parameters was investigated.