CN115258032A

CN115258032A - Gas jet oscillation device and ship

Info

Publication number: CN115258032A
Application number: CN202210812987.1A
Authority: CN
Inventors: 张辉; 侯典俸; 吴宽宇
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2022-07-12
Filing date: 2022-07-12
Publication date: 2022-11-01

Abstract

The invention discloses a gas jet oscillation device and a ship, and relates to the technical field of ship drag reduction. The gas jet oscillation device and the ship can effectively improve the resistance reduction effect while improving the jet coverage area.

Description

Gas jet oscillation device and ship

Technical Field

The invention relates to the technical field of ship drag reduction, in particular to a gas jet oscillation device and a ship.

Background

The gas jet flow resistance reduction technology is a technology that stable gas jet flow is sprayed out of a ship bottom area in the ship advancing process, and a gas-liquid mixing layer covering the bottom surface of a ship is formed after the jet flow is mixed with water, so that the resistance borne by the bottom surface of the ship is reduced. The gas jet oscillation device comprises a gas supply system, a gas inlet, a jet oscillator and a jet outlet. The gas supply system leads gas into the jet oscillator through the gas inlet; the gas is converted into stable gas jet under the action of the oscillator and is emitted from the gas jet outlet.

The traditional single-jet direct impact jet oscillator has the problem of small coverage area of jet flow, namely the size of a gas-liquid mixing layer device formed in water is small; after the traditional single-jet direct impact jet oscillator is simply superposed, although the jet coverage area is improved, the mutual barrier effect between the traditional single-jet direct impact jet oscillator is very obvious, the total jet coverage area is seriously reduced, and a gas-liquid mixing layer with enough area is difficult to generate at the bottom of a ship once.

Disclosure of Invention

The invention aims to provide a gas jet oscillation device and a ship, which are used for solving the problems in the prior art, and effectively improving the resistance reduction effect while improving the jet coverage area.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a gas jet oscillation device which comprises a jet oscillator and a fluid supply assembly, wherein the jet oscillator comprises a main body and at least two groups of self-excitation generating channels, each group of self-excitation generating channels are arranged on the main body side by side, the middle parts of the adjacent self-excitation generating channels are communicated through a communicating cavity, the discharge end of the fluid supply assembly is communicated with one end of each self-excitation generating channel and is used for introducing fluid into the self-excitation generating channels, and the fluid is ejected out through the other ends of the self-excitation generating channels after jet self-excitation oscillation is formed in the self-excitation generating channels.

Preferably, the self-excitation generating channel comprises a fluid inlet, an oscillation cavity and a fluid outlet which are communicated in sequence, the fluid inlet is communicated with the discharge end of the fluid supply assembly, the oscillation cavity is used for self-excitation of fluid, and the fluid outlet is used for jet ejection.

Preferably, the fluid outlet is gradually widened, and the opening of the fluid outlet is gradually increased from the approach direction to the direction far away from the oscillation cavity.

Preferably, the fluid supply assembly includes a high-pressure pump, a storage tank and a transmission pipeline, the storage tank is used for storing fluid, two ends of the transmission pipeline are respectively communicated with the storage tank and the self-excitation generation channel, and the high-pressure pump is communicated with the storage tank and is used for pumping the fluid in the storage tank into the self-excitation generation channel through the transmission pipeline.

Preferably, the transmission pipeline is further provided with a one-way valve, and the one-way valve is used for enabling fluid to be only led into the self-excitation generating channel through the storage tank.

Preferably, a switch is further arranged on the transmission pipeline, and the switch is located between the one-way valve and the storage tank and used for controlling the on-off of fluid in the transmission pipeline.

Preferably, a first pressure gauge is arranged on the storage tank and used for detecting the pressure in the storage tank, a preset pressure value is obtained, and when the pressure detected by the first pressure gauge reaches the preset pressure value, the switch is controlled to be turned on.

Preferably, a second pressure gauge is further installed on the transmission pipeline at a position close to the fluidic oscillator, and the second pressure gauge is used for detecting the pressure in the transmission pipeline.

The invention also provides a ship, which comprises a ship body and a plurality of gas jet oscillation devices in any one of the technical schemes, wherein the gas jet oscillation devices are arranged in the ship body and are used for reducing the resistance of the ship body.

Compared with the prior art, the invention has the following technical effects:

the invention provides a gas jet oscillation device, which comprises a jet oscillator and a fluid supply assembly, wherein the fluid supply assembly is used for providing fluid and initial speed required by self-excitation for the jet oscillator, the jet oscillator comprises a main body and at least two groups of self-excitation generating channels, each group of self-excitation generating channels are arranged on the main body side by side, and two simple self-excitation generating channels are superposed to overcome the problem of small jet coverage area of a single simple oscillator.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a gas jet oscillation device provided in one embodiment;

FIG. 2 is a cross-sectional view of a fluidic oscillator according to one embodiment;

FIG. 3 is a schematic view of the jet direction of a gas jet oscillation device provided in accordance with an embodiment in a first state;

FIG. 4 is a schematic view of the jet direction of the gas jet oscillation apparatus provided in the first embodiment in a second state;

FIG. 5 is a schematic view of the jet direction of the gas jet oscillation device provided in the first embodiment in a third state;

FIG. 6 is a schematic view of the jet direction in a fourth state of the gas jet oscillation apparatus provided in the first embodiment;

FIG. 7 is a schematic structural view of a ship according to a second embodiment;

FIG. 8 is a schematic view of the jet direction of the ship provided by the second embodiment during traveling;

in the figure: 100-gas jet oscillation device, 1-fluid inlet, 2-oscillation cavity, 3-fluid outlet, 4-first pressure gauge, 5-high pressure pump, 6-storage tank, 7-transmission pipeline, 8-switch, 9-one-way valve, 10-second pressure gauge and 200-ship.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a gas jet oscillation device and a ship, and aims to solve the technical problems that the existing gas jet oscillation device is poor in drag reduction effect on the ship and small in jet coverage area.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Example one

As shown in fig. 1 to fig. 6, the present embodiment provides a gas jet oscillation device 100, which includes a jet oscillator and a fluid supply assembly, the fluid supply assembly is configured to provide a fluid and an initial velocity required for self-excitation for the jet oscillator, the jet oscillator includes a main body and at least two sets of self-excitation generation channels, each set of self-excitation generation channels is disposed side by side on the main body, two simple self-excitation generation channels are stacked to overcome the problem of small jet coverage area of a single simple oscillator, the middle portions of adjacent self-excitation generation channels are communicated through a communication cavity, so that air flows ejected from the two self-excitation generation channels are uniform and in the same direction, compared with the existing non-communication simple stacking, consistency of ejected air flows can be ensured, mutual blocking effect between the oscillators is reduced, compared with the conventional gas jet oscillator, the present embodiment can generate a larger area of gas jet within the same time, so as to effectively reduce resistance suffered by a ship hull, the exhaust end of the fluid supply assembly is communicated with one end of the self-excitation generation channel, and is configured to introduce the fluid into the generation channel, and the fluid is ejected from the other end of the self-excitation generation channel after forming self-excitation oscillation in the generation channel, thereby achieving drag reduction 200.

Specifically, the self-excitation generating channels are preferably two, and each channel comprises a fluid inlet 1, an oscillation cavity 2 and a fluid outlet 3 which are sequentially communicated, the fluid inlet 1 is communicated with the discharge end of the fluid supply assembly, so that the fluid supply assembly can conveniently introduce fluid (such as gas) into the fluid inlet 1 to provide fluid required by jet flow, and the initial speed is the initial speed, the fluid in the oscillation cavity 2 is used for self-excitation of the fluid, the fluid outlet 3 is used for jet flow ejection, for the fluid self-excitation principle, when fluid working medium is introduced into high-pressure gas at the fluid inlet 1 due to coanda wall effect, the fluid working medium is randomly deflected to the side of a wall-attached jet flow (assumed to be deflected to the right), a main jet flow can be ejected in the opposite direction of the prior deflection of the fluid outlet 3 (the jet flow is ejected along the left side), and due to the action of a feedback channel in the oscillation cavity 2, the direction of the jet flow at the fluid outlet 3 can be gradually changed (gradually from the left to the right, and then gradually moved to the left), so that a stable self-excitation oscillation cycle is formed, namely jet flow is formed.

The fluid outlet 3 is gradually widened, the openings of the fluid outlet 3 are gradually increased from the direction close to the oscillating cavity 2 to the direction far away from the oscillating cavity 2, two groups of self-excitation generating channels are preferred, the self-excitation generating channels have the characteristic of double-glancing impact jet flow generated by a synchronous jet flow oscillator, and the maximum diffusion angle of the jet flow at the outlet can reach 90 degrees. When the gas jet oscillation device 100 is designed and installed, all structures of the gas jet oscillation device are in threaded connection, so that the gas jet oscillation device is convenient to install and has strong interchangeability; the jet oscillator occupies small space, is convenient to carry, can be used as a high-efficiency spray head in various situations, is not only limited to the resistance reduction of the ship 200, but also can be used in various situations needing to form stable jet, such as the formation of a stable gas-liquid mixing layer, the large-area cleaning of stable jet and the plant irrigation.

The fluid supply assembly comprises a high-pressure pump 5, a storage tank 6 and a transmission pipeline 7, wherein the storage tank 6 is used for storing fluid, preferably gas, two ends of the transmission pipeline 7 are respectively communicated with the storage tank 6 and the self-excitation generation channel, the high-pressure pump 5 is communicated with the storage tank 6 and is used for pumping the fluid in the storage tank 6 into the self-excitation generation channel through the transmission pipeline 7, and therefore the gas discharged from the storage tank 6 is converted into gas jet with a large coverage area.

The transmission pipeline 7 is also provided with a one-way valve 9, and the one-way valve 9 is used for leading fluid into the self-excitation generation channel only through the storage tank 6, so that the fluid is prevented from flowing backwards and the formation of jet flow is prevented from being influenced.

The transmission pipeline 7 is further provided with a switch 8, the switch 8 is located between the one-way valve 9 and the storage tank 6 and is used for controlling on-off of fluid in the transmission pipeline 7 so as to control on-off of the switch 8 according to actual resistance reduction requirements and further control on-off of the fluid.

Be equipped with first pressure gage 4 on holding vessel 6, first pressure gage 4 is used for detecting 6 internal pressures of holding vessel, can survey 6 internal pressures of holding vessel in real time, avoid too big or undersize influence safety in utilization of pressure, simultaneously, predetermine a pressure value (accessible controller realization), this pressure value is the pressure value in the required leading-in transmission pipeline 7 of high-pressure pump 5, when the pressure that first pressure gage 4 detected reachs the predetermined pressure value, control switch 8 opens, gaseous transmission pipeline 7 that flows in rapidly via check valve 9, and then make each stock air current that gets into in the self-excitation emergence passageway have simultaneity and sameness.

The position that is close to fluidic oscillator on transmission line 7 still installs second manometer 10, second manometer 10 is used for detecting the pressure in the transmission line 7, avoid too big influence safety in utilization of pressure, can realize the real-time observation to pressure simultaneously, at concrete during operation, start high-pressure pump 5, when the pressure that awaits measuring first manometer 4 is unanimous with the settlement pressure, start switch 8, high-pressure fluid working medium is one-way entering transmission line 7 under check valve 9's effect, and leading-in to in the self excitation emergence passageway, accomplish that each fluid entry 1 receives the same fluid working medium simultaneously. The structures used in the embodiment are all mechanically controlled, so that the device is convenient to use in various severe environments (such as long-term immersion in water, no power device and strong magnetic field); meanwhile, the integral structure is small and exquisite, the carrying, the installation and the replacement are convenient, the oscillation is formed by self-excitation of the internal oscillation cavity 2, and an additional mechanism is not needed.

Example two

As shown in fig. 7 to 8, the present embodiment provides a ship 200 including a hull and a plurality of gas jet oscillation devices 100 of the first embodiment, the gas jet oscillation devices 100 being installed in the hull and used for drag reduction of the hull. When the ship 200 advances, the gas jet oscillation device 100 is started, gas jet acts on the bottom of the ship 200, the ship advances forwards along with the ship 200, gas jet is rapidly sprayed in a diffusion angle by the jet at the fluid outlet 3 according to a certain rule, namely, a gas jet curve similar to a sine function is formed at the bottom of the ship 200, and a gas-liquid mixing layer is formed by gas flow and water so as to achieve the function of drag reduction, namely, the resistance borne by the ship 200 is reduced by spraying the gas jet at the bottom of the ship 200, so that the transportation cost of the ship 200 is greatly reduced, and the gas jet oscillation device is also suitable for the condition that the friction resistance between solid and liquid walls needs to be reduced.

With regard to the coverage area of the jet at the bottom of the vessel 200, the time taken for one period of the gas jet oscillation device 100 (the states shown in fig. 3, 4, 5, and 6 are sequentially cyclically occurring) can be changed by adjusting (increasing or decreasing) the gas pressure in the transmission line 7, i.e., the curve distribution in fig. 8 is denser, wherein in fig. 3-6, the solid arrows indicate the main jet direction, and the hollow arrows indicate the small jet direction.

The installation density of the gas jet oscillation device 100 on the bottom of the ship 200 and the change frequency of the jet in the diffusion angle can be adjusted according to actual requirements.

The principle and the implementation mode of the present invention are explained by applying specific examples in the present specification, and the above descriptions of the examples are only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, this summary should not be construed as limiting the invention.

Claims

1. A gas jet oscillation apparatus characterized by: the jet flow generator comprises a jet flow oscillator and a fluid supply assembly, wherein the jet flow oscillator comprises a main body and at least two groups of self-excitation generation channels, each group of self-excitation generation channels are arranged on the main body side by side, the middle parts of the adjacent self-excitation generation channels are communicated through a communication cavity, the discharge end of the fluid supply assembly is communicated with one end of each self-excitation generation channel and is used for introducing fluid into the self-excitation generation channels, and the fluid is sprayed out through the other ends of the self-excitation generation channels after jet flow self-excitation oscillation is formed in the self-excitation generation channels.

2. A gas jet oscillation apparatus as claimed in claim 1 wherein: the self-excitation generation channel comprises a fluid inlet, an oscillation cavity and a fluid outlet which are sequentially communicated, the fluid inlet is communicated with the discharge end of the fluid supply assembly, the oscillation cavity is used for self-excitation of fluid, and the fluid outlet is used for jet ejection.

3. A gas jet oscillation apparatus as claimed in claim 2 wherein: the fluid outlet is gradually wide, and from being close to keeping away from in the direction of oscillation chamber, the opening of fluid outlet increases gradually.

4. A gas jet oscillation apparatus as defined in claim 1 wherein: the fluid supply assembly comprises a high-pressure pump, a storage tank and a transmission pipeline, wherein the storage tank is used for storing fluid, two ends of the transmission pipeline are respectively communicated with the storage tank and the self-excitation generation channel, and the high-pressure pump is communicated with the storage tank and is used for pumping the fluid in the storage tank into the self-excitation generation channel through the transmission pipeline.

5. A gas jet oscillation apparatus as defined in claim 4 wherein: and the transmission pipeline is also provided with a one-way valve which is used for leading the fluid into the self-excitation generating channel only through the storage tank.

6. A gas jet oscillation apparatus as defined in claim 5 wherein: and a switch is also arranged on the transmission pipeline, is positioned between the one-way valve and the storage tank and is used for controlling the on-off of the fluid in the transmission pipeline.

7. A gas jet oscillation apparatus as defined in claim 6 wherein: the pressure gauge is used for detecting the pressure in the storage tank and presetting a pressure value, and when the pressure detected by the first pressure gauge reaches the preset pressure value, the switch is controlled to be opened.

8. A gas jet oscillation apparatus as defined in claim 6 wherein: and a second pressure gauge is also arranged on the transmission pipeline close to the jet oscillator and used for detecting the pressure in the transmission pipeline.

9. A ship, characterized by: comprising a hull and a plurality of gas jet oscillation devices according to any one of claims 1 to 8, which are mounted in the hull and serve to reduce drag on the hull.