Investigating the effect of isothermal channel height on the vibrational and thermal behavior of elastically-mounted cylinder affected by unilateral and bilateral jet flow

In this paper, the active flow control of flow-induced vibration of a circular cylinder placed inside the isothermal channel affected by jet injection is studied. The effect of flow injection on heat transfer inside the channel has also been examined. For this purpose, three slots are placed symmetrically in the upper and lower walls of the channel at distances 0, D and 4D where D is the diameter of the cylinder from the side surface. The main innovation of the present study is to evaluate the effectiveness of the proposed flow control method in terms of channel height. For this purpose, 6 channels with heights of 5.5D, 6D, 7D, 8D, 9D and 10D are considered to perform fluid-solid interaction simulations. Numerical results show that for all channels with different heights, jet injection, either unilaterally or bilaterally, from slot 3 has no effect on displacement because the distance of the jet from the cylinder is large. The main reason for the complete reduction of vibrations by the jet flow injection method is seen in suppressing the vortex shedding and consequently reducing the amplitude of hydrodynamic coefficients. The average Nusselt number increases with increasing jet injection velocity and decreasing channel height. The effectiveness of bilateral jets in improving the Nusselt number is more than unilateral jets