This experimental study investigates the wake flow behind a pair of cylinders displaced normal to a free stream and the flow characteristics around staggered cooling tube arrays of fan coil unit used in merchant vessel. This study is also aimed to analyze the transition mechanism of the large vortex generating process in the wake having unique vortex shedding pattern associated with the gap difference between the cylinders. The detailed visualization is carried out using the PIV measurement. The transition mechanism of the large generating vortex is clarified by showing the streak lines, the vorticity and the statistical fluctuating velocity distributions.
As for the results of this experimental study, The flow characteristics around cooling tube of fan coil unit are divided into two distinctly areas between the wake behind cylinder. Flow velocity with pressure drop effects is shown according to various Reynolds numbers. Futhermore, the wake of cylinder shows a vortex region with the periodic flow separation due to the wake unsteady phenomena. With increasing air velocity into fan coil unit, heat transfer is also enhanced at evaporator from the temperature measurement.