Abstract: Turbine comprising a tubular body that receives an upstream stator, a rotor including a propeller and a downstream stator. The trailing edge of the blades of the upstream stator is inclined through a negative angle relative to a normal relative to the axis, and the leading edge of the blades of the propeller is inclined and rounded in an incline directed downstream. The rotational mounting of the propeller in the turbine involves a fixed shaft installed in the upstream and downstream stators, and which carries an upstream bearing bush and a downstream bearing bush, close to the end of the location of the propeller, and a stop formed by a crown of support pins in an upstream and downstream direction. The propeller comprises a tubular hub through which the fixed shaft extends and which has a bearing bush at each end in order to co-operate at the same time with the corresponding bearing bush of the fixed shaft and with the corresponding peripheral stop.

Abstract: The invention concerns a method for measuring the displacement of a fluid in a conduit, by measuring the transit time of ultrasounds between two transducers (12, 13), in one direction and in the other, characterised in that it consists in: simultaneously exciting (16) both transducers; then simultaneously measuring (17, 18) the signals received on each of the transducers coming from the other transducer. The measured signals can then be digitised and correlated to determine the difference between the transit times. The invention enables to obtain faster and more reliable, measurement of transit times between transducers.