Asymmetric duct for behind ship propeller

A rear propeller, asymmetrical technology, applied in ship propulsion, ship components, ship construction, etc., to achieve the effect of equalizing the stern wake, improving efficiency, and improving wake

Inactive Publication Date: 2019-07-23
HARBIN ENG UNIV
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional duct mainly plays the role of changing the propeller load and providing additional thrust, and has little effect on improving the stern wake, reducing the stern excitation force and noise

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Asymmetric duct for behind ship propeller
  • Asymmetric duct for behind ship propeller
  • Asymmetric duct for behind ship propeller

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0023] The following examples describe the present invention in more detail.

[0024] to combine figure 1 and figure 2 , the asymmetric duct used for the rear propeller of the present invention is symmetrical left and right, and its cross section varies along the circumference according to the wake of the stern. The camber and angle of attack of its airfoil section vary according to the axial wake of the stern. The upper part uses the form of accelerating duct to increase the axial velocity of the water flow in front of the propeller; the lower part uses the form of decelerating duct to reduce the axial velocity of the water flow in front of the propeller. Thereby, the wake at the propeller disc surface is uniformized, thereby improving the propeller efficiency, and greatly reducing the vibration and noise of the propeller.

[0025] to combine image 3 as well as Figure 4a to Figure 4e , image 3 5 cross-sections at 5 positions of the asymmetric catheter are marked in ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides an asymmetric duct for a behind ship propeller. The duct is symmetric left and right, an inlet and an outlet of the duct are irregular curves and are not in a plane, the top ofthe inlet curve is inward concave, the middle and bottom of the inlet curve are flat and smooth, a sharp protrusion is arranged at the top of the outlet curve and declines from the top curve to the middle curve in a straight line shape, an outer protrusion is arranged in the middle, the camber and an attack angle along the duct perimeter profile wing section profiles change in the axial direction,and the shapes and thicknesses of the various profiles in the length direction of the duct are different. The asymmetric duct can improve wake of a stern, so that the asymmetric wake at a propeller disc surface is homogenized, vibration noise of the propeller is reduced and the efficiency of the propeller is improved, so that the effects of improving the efficiency and improving the vibration noise are achieved.

Description

technical field [0001] The present invention relates to a duct, in particular to a duct used for a ship's rear propeller. Background technique [0002] When an object such as a ship moves in water, the wake field will be generated due to the uneven distribution of velocity behind the object. The uneven wake field will affect the propeller, and the drastic change of the water flow at the propeller disk will cause uneven load on the propeller blades, which will cause great excitation force and noise at the tail of the ship. Since the late 20th century, the asymmetry of the ship's wake field has received extensive attention, and many methods for improving the wake of the propeller disk have emerged. There are two main methods, one is to improve the stern wake by optimizing the tail line design. The other is to install rectifying appendages on the ship, such as some special devices such as rectifying fins, compensating ducts, and front ducts. Among them, the ducted propeller ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): B63H5/15
CPCB63H5/15
Inventor 胡健毛翼轩王英铸李涛陈昉张维鹏赵旺王子斌
Owner HARBIN ENG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap