Within the framework of some theses hypersonic flows have been investigated theoretically as well as by experiments in the hypersonic facility Gun Tunnel of the institute. Some of these activities during the last years are summarized. The first problem is of a blunt body of revolution with subsonic blowing in the stagnation point region against the hypersonic main flow. Surface pressure and heat transfer measurements have been carried out for two bodies at different free-stream Machnumbers and for various blowing rates. Remarkable agreement has been obtained in comparison with a combination of Newtonian and potential theory. The second problem is of the hypersonic flow in corners formed by intersecting swept wedges. The corner angle and the leading-edge sweep angle have been varied systematically. The flow field has been analysed by means of pitot pressure measurements in a characteristic cross-section and the flow structure near the wall has been determined from oilflow pictures as well as from wall pressure and heat transfer measurements. Strong vortical flows have been detected underneath the corner shock system. Starting from a 90 deg corner of unswept wedges, the heat flux in the corner center can be reduced considerably by increasing the corner angle and by sweeping the leading-edges back.