Abstract: The invention relates to a sonotrode for the ultrasonic welding of plastic components of an electronic cigarette. The sonotrode comprises: a body comprising a first end which can be connected to an ultrasound generator, and a second end; a cavity that develops from the second end towards the first end, for receiving at least partially a plastic component of an electronic cigarette to be welded. The cavity defines an opening at the second end of the body, communicating with the outside of the sonotrode. In particular, at the opening, the cross section of the cavity has an outline comprising: a first portion that has the shape of a first arc of a reference circumference, which comprises a first end and a second end, opposite each other; and a second portion, that has the shape of a second arc of said reference circumference, which comprises a first end and a second end, opposite each other.

Abstract: The invention relates to a sonotrode for the ultrasonic welding of plastic components of an electronic cigarette. The sonotrode comprises: a body comprising a first end which can be connected to an ultrasound generator, and a second end; a cavity that develops from the second end towards the first end, for receiving at least partially a plastic component of an electronic cigarette to be welded. The cavity defines an opening at the second end of the body, communicating with the outside of the sonotrode. In particular, at the opening, the cross section of the cavity has an outline comprising: a first portion that has the shape of a first arc of a reference circumference, which comprises a first end and a second end, opposite each other; and a second portion, that has the shape of a second arc of said reference circumference, which comprises a first end and a second end, opposite each other.

Abstract: The surge pressure ratio of a compressor is determined by transiently reducing the inlet flow to the compressor to increase the compressor pressure ratio sufficiently to produce the surge pressure ratio. The reduction in flow of fluid is maintained for a time period insufficient to exceed the exhaust gas temperature limit for the turbine. The area of the first-stage nozzle of the turbine is reduced and the inlet flow to the compressor is reduced to a steady state to achieve pressure ratios, in close proximity to the surge line. By transiently further reducing the inlet flow to the compressor and then increasing the inlet flow back to the steady-state condition, the surge pressure ratio can be obtained without exceeding machine operational limits.