Heat transfer and vibration response of a stationary cylinder and an elastic cylinder under mutual interference

Flow-induced vibration (FIV) of bluff bodies is an important safety-related issue in heat exchange equipment. The interaction of oscillation and heat exchange of two circular cylinders in staggered arrangement was numerically investigated. One cylinder (S-cyl.) is stationary and another cylinder (V-cyl.) undergoes FIV in the transverse flow direction. The influences of the spacing (S) and staggered angle (phi) of the two cylinders on the FIV response, near-wake structure, Nusselt number, and temperature distribution were studied. The results show that when the phi and S increase, the vortex pattern undergoes the following changes: double-row vortex street, 2S -> S + P -> 2S, three-row vortex street. As the staggered angle raises, the amplitude of V-cyl. firstly reduces to the lowest value, then increases and finally decreases. The maximum amplitude 0.79D is obtained when phi = 45 degrees and S/D = 1.5 for the V-cyl. For the S-cyl., the local Nusselt number (NuL) generally peaks near the front stagnation point, and the main difference in the distribution of NuL can be observed around the back stagnation point. The averaged Nusselt number (NuA) of two cylinders rises as phi changes from 0 degrees to 45 degrees for S/D = 1.5. The maximum NuA increases by 54%. The change trends of NuA for the V-cly. with staggered angle are similar for S/D > 1.5.