Experimental study of the dynamic characteristics of a cyclone by hot wire/film anemometry: Effects of gas leakage

•Dynamic characteristics are described by fluctuations of tangential velocity.•Gas leakage caused the vortex core to swing from geometric center to wall.•Vortex tail has been located by tangential velocity measurement at first time.•High frequency (~131 Hz) was produced by the rotation of the quasi-forced vortex.•Low frequency (~35 Hz) was related to the swing of the vortex core.