Title: Lipschitz Continuous Subsonic-sonic Flows in General Nozzles

Speaker: Prof.Chunpeng Wang （Jilin University）

Time: Mon, Nov.13, 2017,PM 04:30-05:30

Location: Room 4318, Building No.4, Wushan Campus

Abstract: This talk concerns subsonic-sonic potential flows in two dimensional nozzles. For a finitely long symmetric nozzle which is suitably flat near the throat (where the cross section is smallest) and whose wall is parallel to the symmetric axis at its two endpoints, we formulate the subsonic-sonic flow problem by prescribing the flow angle at the inlet and the outlet. It is shown that there is a unique subsonic-sonic flow whose acceleration is bounded for such a problem. Moreover, its sonic points must occur at the wall or the throat. More precisely, there exists a critical value such that the flow is sonic on the whole throat if the height of the nozzle is not greater than this critical value, while the sonic points must be located at the wall if the height is greater than this value. There are similar results for infinitely long symmetric nozzles and the asymptotic behavior at the infinity of subsonic-sonic flows are shown.