The wind tunnel null which has the free jet measurement interval which simulates the direction change of the wind

摘要

A wind tunnel with an open jet measurement section for simulating wind direction changes, preferably for testing vehicles, is provided with a nozzle that can be swivelled during operation of the wind tunnel in order to change the wind direction. The front part of the nozzle is surrounded by a cylindrical surface sealed with respect to the measurement chamber in the front face of the nozzle pre-chamber, in the manner of a plug. When the front part of the nozzle is swivelled, a compensating flow may be generated within the nozzle prechamber which surrounds the nozzle, so that the quality of the jet blowing in the wind tunnel is only imperceptibly affected, if at all, by the swivelling movement. To allow flow-acoustic problems to be analyzed with changing wind direction, the wind tunnel may be provided with sound insulating and sound absorbing arrangements, as well as with an absorbing lining.