An extremely low speed, compact pump propulsion system inlet channel and its design method

Abstract

The invention discloses a very low speed, compact pump propulsion system inlet channel geometry and a design method thereof, including that the channel geometry is obtained by setting out the channel outlet circle, axial surface projection curve and inlet section curve in three-dimensional CAD software . The diameter of the outlet circle of the flow channel is equal to the diameter of the pump inlet; the axial surface projection curve is controlled by three geometric parameters: the inclination angle of the flow channel, the radial installation height and the arc radius of the upper wall of the elbow section; the section curve of the inlet is square and Semi-elliptical composite curve, controlled by the outlet diameter of the flow channel and the inclination angle of the flow channel; the upper wall surface of the axial projection curve includes the elbow section, transition section and back arc section, and the lower wall surface includes the elbow section and lip arc section In the section, the inclined straight pipe section of the medium and high speed flow channel is cancelled, and it has the geometric shape characteristics of the shortest in the radial direction and the shortest in the axial direction. The design speed of the inlet channel is 12 knots, the inclination angle of the channel is 25 degrees, the diameter of the channel outlet is 1 meter, the radial installation height is 0.7 meters, the radius of the upper wall of the elbow section is 2.42 meters, and the total axial length is 4.18 meters. The non-uniformity coefficient is 0.137, no flow separation and cavitation are generated, and the total propulsion efficiency after matching with the pump is not less than 0.5, realizing the parametric design of the extremely low speed flow channel under the shortest and shortest conditions. The design method is applicable to typical transom jet pumps, submerged jet pumps and built-in pump jet propulsion systems. After popularization and application, it can effectively promote the engineering application of pump propulsion systems on special propulsion platforms.

Description

A very low speed, compact pump propulsion system inlet flow channel and design method thereof technical field The present invention relates to the technical field of marine propellers, particularly to those with low design speed and strict restrictions on installation space. Pump propulsion system, including transom jet propulsion system and built-in pump jet propulsion system. Background technique The main battleship of the western naval power in the 21st century, the Littoral Combat Ship (LCS), adopts a water jet (Waterjet, Jane Pump jet), "Virginia" class and "Smart" class nuclear submarines use pump jet propulsion (Pumpjet, referred to as pump jet), marking the Jet pumps and pump-jet-based pump propulsion systems have embarked on a fast track in the application of high-performance ship propulsion. From the structural layout Judging from the fact that jet pumps are mostly used in surface ships, there are two common types of sternboard jet pumps and submerged jet ...

AI Technical Summary

Problems solved by technology

The above conclusions and measures have a certain enlightening effect on the design of the extremely low speed and compact water inlet flow channel of the present invention, but the geometric parameters of the flow channel and the design process thereof are not given in the above inventions, which cannot be reproduced, nor can it be judged whether it can be used for extremely low speed. Low speed propulsion needs

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