CN2071163U

CN2071163U - Non-symmetric double tail fin ship mould

Info

Publication number: CN2071163U
Application number: CN 90207128
Authority: CN
Inventors: 叶立钦; 陈昌运
Original assignee: Traffic Department Shanghai Scientific Research Institute Of Shipping
Current assignee: Traffic Department Shanghai Scientific Research Institute Of Shipping
Priority date: 1990-04-11
Filing date: 1990-04-11
Publication date: 1991-02-13

Abstract

The utility model discloses a non-symmetric double tail fin ship mould, whose main distinction from the existing double tail fin ship mould is that the tail fins thereof are non-symmetric, namely, non-axial-symmetric and non-plane-symmetrical. The non-symmetric tail fin, which is matched with a propeller, can effectively overcome the existing problem of the existing symmetric double tail fin ship mould: (1) the contradiction between propulsion performance and manipulating performance, (2) the contradiction between energy saving and shock reduction.

Description

Non-symmetric double tail fin ship mould

The utility model is a kind of new ship type, and it relates to the hull tail structure.Particularly relate to improvement to double tail fins.

Along with the appearance and the development of a kind of so-called shallow draft or Ultra Shallow Draft Vessel, propulsion of ship is also advanced to two oars by single-blade gradually and advances transition, and r Zweier adopts double bracket afterbody form during beginning, and its resistance of this form, propulsion quality are poorer than the single-blade ship.Afterwards, double tail fins ship type occurs, this ship type makes the hull efficiency of r Zweier approach the single-blade ship, and total drag also is more or less the same with the single-blade ship, therefore, its quick performance is better (referring to the kind former grade of Lang Liu " Twln-Skeg stern ship type on the river than single-blade ship behind the employing double tail fins The research of propulsion quality experiment " Japanese ship skill reports that the 18th rolled up 1981).But current double tail fins ship type, its tail fin shape all is symmetric form, further studies show that, there are two subject matters again in symmetric form double tail fins ship type: the contradiction of (1) propulsion quality and maneuvering performance: because this ship type is when cooperating the screw propeller of inward turning direction, the propulsion coefficient height, propulsion coefficient during outward turning is much lower during than inward turning, and r Zweier often adopts with car and realizes control to motion of ship for the operation of rudder, the rotation direction of screw propeller to the boats and ships influence greatly, the screw propeller of inward turning with car for behaviour's ship of rudder in effect relatively poor, sometimes even can occur and require opposite motion.Therefore most of boats and ships because road-holding property is had to abandon propulsion coefficient and imitated high inward turning oar and adopt the outward turning oar, make double tail fins ship propulsion coefficient lower like this, and what preceence compares with the support ship type of routine does not have.(2) contradiction of energy-conservation and vibration damping: the stern wake field of symmetric double tail fin ship type is very inhomogeneous, top position at propeller disk, often exist higher wake peak, and near the local wake gradient the peak value is bigger, cause screw propeller to produce cavity and induce the local exciting of hull easily like this,, then reduced hull efficiency again if remove wake peak, in other words, the double tail fins ship type of symmetric form exists energy-conservation again and contradiction vibration damping.

The purpose of this utility model is exactly in order to solve or improve the problem of above-mentioned symmetric double tail fin ship type existence, when even double tail fins ship type cooperates with outward turning propeller, also can obtain and the cooresponding propulsion coefficient of inward turning spiral shell, make the stern wake field more even, avoid screw propeller to produce cavity, reduce the hull local vibration.

The purpose of this utility model is achieved in that with a kind of asymmetric double tail fin ship type and replaces existing symmetric double tail fin ship type.So-called asymmetric double tail fin ship type is meant that in screw propeller the place ahead normally the tail fin shape at place, 1 station is neither rotational symmetry, on-plane surface symmetry again.

Owing to improve propulsion of ship efficient, improve the propeller cavitation performance, reduce the hull local vibration, all closely related with the distribution situation of potential wake field, and mainly being hull shape with screw propeller the place ahead, the distribution situation of wake field directly interrelates, therefore for obtaining desirable wake field, mainly be the hull form to oar the place ahead, particularly the tail fin shape is improved.Test shows: when double tail fins is asymmetrical shape, can obtain good wake field, the direction of the tangential speed component in the flow field is opposite with the screw propeller rotation direction, help improving propulsion coefficient, propulsion coefficient when propulsion coefficient during the outward turning oar and symmetric form tail fin ship type inward turning oar is suitable, axial velocity component in the flow field distributes more even along the oar dish, thereby make the thrust of screw propeller, the torque ripple amplitude is less, wake peak value in the wake field is less, local wake gradient is less near the peak value, the danger of the ship vibration that can make screw propeller produce cavity and induce reduces, and generally all can make the control of cavity vibration situation within the range of permission.

For clearer the utility model is illustrated.Further set forth concrete enforcement below in conjunction with accompanying drawing.

Fig. 1: be hull afterbody schematic side view.

Fig. 2: be hull afterbody schematic cross section.

Fig. 3: be hull afterbody elevational schematic view.

With reference to accompanying drawing, among Fig. 1: 0,1,2 expression station numbers, 11-hull, 12-tail fin, 13-screw propeller, 14-rudder, 15-prop shaft.Two sides at the vertical midship section of hull 11 afterbodys are provided with two tail fins 12, and at place, 1 station, the shape of tail fin is an asymmetry usually, neither rotational symmetry, on-plane surface symmetry again, the bottom of fin is big than top generally, can make that wake is evenly distributed, keep higher average wake.Be " peach " sub-shape in tail fin bench section, place, 1 station, the top of fin body slopes inwardly, and the below is outward-dipping, and the upper end of tail fin is connected as shown in Figure 2 with hull, and the 0-10 label among the figure is the hull afterbody.The section station number at each station, their shape cooperate 1 station section shape fairing to form.Screw propeller oar axle is all surrounded by the fin body.As shown in Figure 3.

Below just summarized the utility model and existing boats and ships key distinction part, other and existing ship something in common, be interpreted as with existing ship usually the technology of employing be as good as.

Claims

1, a kind of asymmetric double tail fin ship type comprises hull (11), screw propeller (13), double tail fins (12), rudder (14), it is characterized in that double tail fins is asymmetric, and the upper end of tail fin is connected with hull, and prop shaft is all surrounded by the fin body.

2, ship type as claimed in claim 1, it is characterized in that: the bottom of asymmetric double tail fins is bigger than top.

3, ship type as claimed in claim 1 is characterized in that the top of the fin body of asymmetric double tail fins slopes inwardly, and the bottom is outward-dipping.