In impinging jets, vortices from incoming jets play a key factor in enhancing heat transfer. One mechanism to produce vortices is a two parallel plane jet, reported to have a periodic vortex shedding at certain jet spacing ratios and increase turbulent mixing. In this study, particle image velocimetry (PIV) measurements were done for a two parallel plane free jet with a vortex shedding phenomenon and a two parallel plane impinging jet with the same exit conditions. Turbulence statistics were focused upon to determine the effects created by the impingement plate upon a two parallel plane jet. Both cases showed a periodic vortex shedding phenomenon, but the impinging jet showed a smaller vortex shedding frequency, due to the pressure gradient caused by the impingement plate. Average velocities showed similar tendencies in the free jet region. However, once past 50% of the impingement height, differences emerged both in average velocity and turbulent statistics signifying the beginning of the impingement region. Due to a constant transverse flow, time-varying components were minimal in the impingement region, causing turbulence statistics to become smaller in the region. It can be said that the impingement plate does not prevent the vortex shedding phenomenon at the set impingement height, but causes turbulence statistics in downstream regions to decline for a two parallel plane impinging jet.

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