Numerical study on laminar flow over three side-by-side cylinders

The present study has numerically investigated two-dimensional flow over three circular cylinders in an equidistant side-by-side arrangement at a low Reynolds number. For the study, numerical simulations are performed, using the immersed boundary method, in the range ofg* < 5 at Re=100, whereg* is the spacing between two adjacent cylinder surfaces divided by the cylinder diameter. Results show that the flow characteristics significantly depend on the gap spacing and a total of five kinds of wake patterns are observed over the range: modulationsynchronized (g*≥2), inphase-synchronized(g*≈l.5), flip-flopping (0.3<g*≲1.2), deflected (g*≈0.3), and single bluff-body patterns (g*<0.3). Moreover, the parallel and symmetric modes are also observed depending ong* in the regime of the flip-flopping pattern. The corresponding flow fields and statistics are presented to verify the observations.