抄録
It is well known that some of the noise sources of noise which radiate from an exhaust pipe of automobile engine exist in the flow field downstream of the pipe end. An unsteady jet issues periodically from the pipe end with shock wave, so that the discharged shock interacts with the jet, resulting in the formation of the complicated flow pattern. To clarify the mechanism of noise generation, the flow field downstream of the pipe end is experimentally examined using a shock tube. The shocks are successively discharged from open end of the pipe. The first shock induces the jet from the pipe end. And the following shock interacts with the jet. The flow field is visualized by shadowgraph method and different types of pressure waves are observed.
