Instability of liquid jet penetrated into stream in channel

Penetration process and an instability on a liquid jet impinging to a stream of the same fluid in a channel is focused. The jet penetrated into the stream is wrapped by entrained air, and coalesces with the stream when the air sheath around the jet collapses. We introduce instability arisen on the jet and the vigorous effect of the entrained-air sheath on the dynamic behavior of the jet in this fluid dynamics video.