Transient Characteristics of Water-Jet Propulsion with a Screw Mixed Pump during the Startup Process

Abstract EN

In order to investigate the transient hydrodynamic characteristics of water-jet propulsion with a screw mixed pump during the startup period and to overcome the difficulties in measuring the transient process parameters over a very short period of time, a method based on a flume experiment combined with computational fluid dynamics (CFD) is proposed.

The thrust and torque of the pump-jet propulsion according to mooring status at different rotational speeds were measured by the test, which provided a group of data for the boundary and initial conditions of the numerical calculation of the user-defined function (UDF).

Consecutive changes in the parameters of the water-jet propulsion dynamics can be captured from the numerical simulation of the startup process with the UDF.

Thus, the transient hydrodynamic characteristics of water-jet propulsion according to time or rotation speed were obtained.

The results show that the relationship between the thrust or torque of the water-jet propeller and pump rotational speed is close to the quadratic functions.

The energy characteristic parameters of screw mixed water-jet pump, such as the flow rate, head, shaft power, and efficiency, rapidly increase and decrease and then remain relatively stable.