阅读说明：本技术 一种转速可调的双涵道喷水推进泵 (Double-duct water jet propulsion pump with adjustable rotating speed ) 是由 陈泰然 鲁航 王国玉 张富毅 耿昊 谢晓天 于 2021-02-10 设计创作，主要内容包括：本发明涉及一种转速可调的双涵道喷水推进泵,属于流体机械工程、水上航行器领域。该装置采用内嵌式双涵道并联泵,实现多级嵌套,简化导叶和叶轮处的交界面,内外泵均采用轴流泵设计,外泵轮毂采用中空设计,内泵叶轮外径为外泵轮毂内径。内泵与传统泵相同,采用轮毂内的轴向电机驱动,外泵采用传动轴进行传动。本发明在提升推力性能和小流量下的扬程的基础上,还可以实现内外涵道各自调配转速,形成全新的流域流道,同时可以提高抗空化性能,可以广泛应用于船舶、两栖车辆、潜艇和水下潜器等技术领域。(The invention relates to a double-duct water jet propulsion pump with adjustable rotating speed, belonging to the field of fluid mechanical engineering and water navigation devices. The device adopts embedded two duct parallel pumps, realizes multistage nestification, simplifies the interface of stator and impeller department, and interior outer pump all adopts axial-flow pump design, and outer pump wheel hub adopts the cavity design, and inner pump impeller external diameter is outer pump wheel hub internal diameter. The inner pump is the same as the traditional pump, and is driven by an axial motor in the hub, and the outer pump is driven by a transmission shaft. On the basis of improving the thrust performance and the lift under low flow, the invention can also realize the respective allocation of the rotating speed of the inner duct and the outer duct to form a brand-new basin flow passage, can improve the anti-cavitation performance at the same time, and can be widely applied to the technical fields of ships, amphibious vehicles, submarines, underwater vehicles and the like.)

1. The utility model provides a two duct water jet propulsion pumps of rotational speed adjustable which characterized in that: the pump comprises an outer pump transmission shaft, an inlet straight pipe, an outer pump impeller chamber, an outer pump impeller, an outer pump guide vane chamber, an outer pump guide vane, an inner pump impeller chamber, an axial motor, an inner pump impeller, an inner pump guide vane chamber and an inner pump guide vane;

the front end of the outer pump transmission shaft is connected with a power output shaft of the engine, and the rear end of the outer pump transmission shaft is connected with an outer pump impeller;

the inlet straight pipe is an equivalent section pipeline, is connected with the outer pump impeller chamber through a flange plate and is connected with a water inlet flow channel fixed on a ship through a flange;

the outer pump impeller chamber is of an equal-diameter cylindrical structure and is connected with the inlet straight pipe section and the outer pump guide vane chamber through bolts;

the outer pump impeller is a main acting part and is positioned in an outer pump impeller chamber to convert mechanical energy input by an outer pump transmission shaft into energy of fluid, the blades are fixed on a hub through nuts and positioning pins, and the hub is fixedly connected with the outer pump transmission shaft;

the outer pump guide vane chamber is of a reducing pipe structure and is connected with the outer pump impeller chamber through a bolt, and the outlet end of the outer pump guide vane chamber is provided with a flange plate which can be connected with the nozzle section;

the outer pump guide vane is positioned in the outer pump guide vane chamber and integrated with the outer pump guide vane chamber, the outer pump guide vane has the functions of eliminating the circumferential velocity component of water flow, performing rectification and converting the rotary motion of the water flow flowing out of the impeller into axial motion, and the hub of the outer pump guide vane is of a hollow structure and is used for arranging the inner pump impeller and the inner pump guide vane;

the inner pump impeller is a work-doing part and is arranged in the outer pump guide impeller hub, the transmission shaft is driven by the axial motor arranged in the outer pump guide impeller hub to drive the inner pump impeller to rotate, and the fluid flowing through the inner pump does work through the outer pump blades, so that the pressure is higher, and the requirement on the anti-cavitation performance of the inner pump is lower.

2. The dual-bypass water jet propulsion pump with adjustable rotation speed of claim 1, wherein: the inner pump is of a low-resistance wing type.

3. The dual-bypass water jet propulsion pump with adjustable rotation speed of claim 2, wherein: the inner pump is an airfoil of a Ge Ding and NACA44 series with the maximum thickness position of the airfoil being 0.3-1.3 chord length away from the leading edge; or the inner pump rotating speed is 115% -145% of the outer pump rotating speed.

4. The dual-duct water jet propulsion pump with the adjustable rotating speed of claim 1, wherein: the size of the blade is obtained by the following method:

designing an inner pump blade based on a discrete vortex lattice method; under the condition of giving radial and chordwise distribution of the ring vector, a plurality of control points are arranged on the surface of the initial blade, and iterative calculation is carried out through the resultant speed obtained by the formula (3) until the object plane boundary condition of the blade arch cambered surface is met, so that the final shape of the blade arch cambered surface is determined, and the initial shape of the blade is finally determined;

firstly, dividing M intervals on an initial surface along a radial direction, and dividing N grids along a chord direction; then, arranging a control point at the core of each grid, arranging a line source and a spanwise vortex at 1/4 chord lengths, arranging a chordwise vortex on a chordwise connecting line of the spanwise vortex end point, and setting the induced velocity of a vortex system on the control point:

wherein: (i, j) is a control point; (m, n) is a load point; k is the number of leaves; gamma-shaped_nm ^sIs the spanwise vorticity; gamma-shaped_nm ^cChord vortex strength; gamma-shaped_nm ^tWake vortex intensity; gamma-shaped_tipTip vortex strength; gamma-shaped_hubHub vortex strength;

the induction speed of the source system on the control band is as follows:

wherein: q_nmIs the strength of the source sink; k^Q _ijnmkFor line source elements on the K bladeThe influence coefficient of (a); the resultant velocity at the (i, j) th control point in the flow field is:

wherein: k^Q _ijnmkThe influence coefficient of the line source element on the Kth blade is shown; q_nmIs the strength of the source sink;

and (3) arranging a plurality of control points on the surface of the initial blade, and performing iterative calculation through the resultant velocity obtained by the formula (3) until all the control points on the blade meet the boundary condition of an object plane with the total found velocity equal to zero, so as to obtain the final shape of the blade.

5. The working method of the rotation speed adjustable double-duct water jet propulsion pump as claimed in claim 1, 2 or 3, characterized in that: water flow enters a pipeline through a water inlet of the inlet straight pipe and is guided to the outer pump impeller chamber through the inlet straight pipe, power is transmitted to an outer pump transmission shaft through a power output shaft of an engine, the outer pump transmission shaft drives blades of an outer pump impeller to rotate, work is done through rotation of the outer pump impeller, pressure energy and kinetic energy of the water flow are improved, a part of water flow eliminates circumferential velocity components through outer pump guide vanes, a part of water flow passes through the inner pump impeller, pressure energy generated by the outer duct impeller is increased in the part of incoming flow, the cavitation resistance of inner duct impeller blades is favorable, work is done through rotation of the inner pump impeller, the pressure energy and the kinetic energy are further improved, the circumferential velocity components are eliminated through the inner pump guide vanes, and the two parts of water flow are converged at the outlet of the outer pump impeller chamber and are finally sprayed out.

Technical Field

The invention relates to a double-duct water jet propulsion pump with adjustable rotating speed, belonging to the field of fluid mechanical engineering and water navigation devices.

Background

In order to improve the propelling performance and meet the shipbuilding trend of shallow draft and high navigational speed, the traditional propeller can not meet the increasingly complex design requirements of the underwater environment. The water jet propeller is a special propulsion mode different from a propeller, and mainly comprises a water inlet flow channel, a water jet propulsion pump, a nozzle and a reversing water bucket. Water flow is introduced through the water inlet flow channel, energy is increased through the water jet propulsion pump, the water flow is sprayed out from the rear of the ship body at a better speed through the nozzle, and the ship or other carriers obtain reverse thrust to move forwards. Steering operation can be realized by controlling the nozzle; by controlling the reversing water bucket, the reversing operation can be realized. When the reverse car hopper is pulled up, the ship body obtains a reverse acting force and moves forwards due to the fact that water flow sprayed out from the nozzle to the rear part of the stern is not physically blocked; when the reverse hopper is put down, the water flow sprayed out from the nozzle to the rear of the stern changes the spraying direction from the rear right behind the stern to the front right ahead of the bow due to the blockage of the reverse hopper, so that the ship body obtains backward thrust to form the operation of reversing. Compared with a propeller, the water jet propeller has the advantages of good maneuverability, strong cavitation resistance, higher relative efficiency at high speed, small vibration, low noise, shallow draft and the like, and is widely applied to navigation bodies such as ships, amphibious vehicles, submarines and the like.

The core component of the water jet propeller is a water jet propeller pump, and the invention adopts an axial flow pump with the advantages of high flow and low lift. In order to show the advantages of the double-bypass pump, the hydraulic performance of the inner pump and the hydraulic performance of the outer pump are similar, the specific rotating speed is the most conventional and most effective basis for measuring the hydraulic performance of the pump, and the lift is the main parameter for measuring the propelling performance of the pump, so that the specific rotating speed and the lift of the inner and outer bypass pumps in all sizes are kept the same when the double-bypass pump is drawn.

At present, the research on the water jet propulsion pump at home and abroad is not deficient, but most of the water jet propulsion pumps only aim at the traditional water jet propulsion pump, and the water jet propulsion pump does not have too many great innovations on the structure. For the axial-flow pump with large diameter blades and low rotating speed, the rotating speed of the shaft is gradually reduced along with the gradual increase of the size of the impeller, the impeller of the central watershed close to the hub is less stressed, the flow rate is low, the space utilization rate is not high, and the overall performance of the pump is reduced.

Through the research of documents, related patents related to the double-duct variable-speed water jet propulsion device are discovered for a while. Aiming at the current defects, the invention provides the double-duct water jet propulsion pump which can simultaneously realize independent work of the inner pump and the outer pump and respective regulation of the rotating speed on the premise of keeping the respective performances of the inner duct pump and the outer duct pump.

Disclosure of Invention

The invention aims to solve the problems of low space utilization rate and low overall performance of the existing water jet propeller and provides a double-duct water jet propeller pump with adjustable rotating speed. The device adopts embedded two duct parallel pumps, realizes multistage nestification, simplifies the interface of stator and impeller department, and interior outer pump all adopts axial-flow pump design, and outer pump wheel hub adopts the cavity design, and inner pump impeller external diameter is outer pump wheel hub internal diameter. The inner pump is the same as the traditional pump, and is driven by an axial motor in the hub, and the outer pump is driven by a transmission shaft. On the basis of improving the thrust performance and the lift under low flow, the invention can also realize the respective allocation of the rotating speed of the inner duct and the outer duct to form a brand-new basin flow passage, can improve the anti-cavitation performance at the same time, and can be widely applied to the technical fields of ships, amphibious vehicles, submarines, underwater vehicles and the like.

The purpose of the invention is realized by the following technical scheme:

a double-duct water jet propulsion pump with adjustable rotating speed comprises an outer pump transmission shaft, an inlet straight pipe, an outer pump impeller chamber, an outer pump impeller, an outer pump guide vane chamber, an outer pump guide vane, an inner pump impeller chamber, an axial motor, an inner pump impeller, an inner pump guide vane chamber and an inner pump guide vane.

The front end of the outer pump transmission shaft is connected with an engine power output shaft, and the rear end of the outer pump transmission shaft is connected with an outer pump impeller;

the inlet straight pipe is an equivalent section pipeline, is connected with the outer pump impeller chamber through a flange plate and is connected with a water inlet flow channel fixed on a ship through a flange;

the outer pump impeller chamber is of an equal-diameter cylindrical structure and is connected with the inlet straight pipe section and the outer pump guide vane chamber through bolts;

the outer pump impeller is a main acting part and is positioned in an outer pump impeller chamber to convert mechanical energy input by an outer pump transmission shaft into energy of fluid, the blades are fixed on a hub through nuts and positioning pins, and the hub is fixedly connected with the outer pump transmission shaft;

the outer pump guide vane chamber is of a reducing pipe structure and is connected with the outer pump impeller chamber through a bolt, and the outlet end of the outer pump guide vane chamber is provided with a flange plate which can be connected with the nozzle section;

the outer pump guide vane is positioned in the outer pump guide vane chamber and integrated with the outer pump guide vane chamber, the outer pump guide vane has the functions of eliminating the circumferential velocity component of water flow and rectifying, and a hub of the outer pump guide vane is of a hollow structure and is used for arranging an inner pump impeller and an inner pump guide vane;

the inner pump impeller is a work-doing part and is arranged in the outer pump guide impeller hub, the transmission shaft is driven by the axial motor arranged in the outer pump guide impeller hub to drive the inner pump impeller to rotate, and because fluid flowing through the inner pump does work through the outer pump blades and the pressure is high, the requirement on the anti-cavitation performance of the inner pump is low, and a low-resistance wing type is preferably selected. For the pump with the cavitation bubble lower than the rotating speed C, Ge Ding and NACA44 series airfoils can be selected, the maximum thickness positions of the airfoils are all at the distance l (l is the chord length) from the leading edge (0.3-1.3), and the ancient Hill airfoils can also be used, wherein the rotating speed of the inner pump is 115% -145% of that of the outer pump;

designing an inner pump blade based on a discrete vortex lattice method; under the condition of giving radial and chordwise distribution of the ring vector, a plurality of control points are arranged on the surface of the initial blade, and iterative calculation is carried out through the resultant speed obtained by the formula (3) until the object plane boundary condition of the blade arch cambered surface is met, so that the final shape of the blade arch cambered surface is determined, and the initial shape of the blade is finally determined;

firstly, dividing M intervals on an initial surface along a radial direction, and dividing N grids along a chord direction; then, arranging a control point at the core of each grid, arranging a line source and a spanwise vortex at 1/4 chord lengths, arranging a chordwise vortex on a chordwise connecting line of the spanwise vortex end point, and setting the induced velocity of a vortex system on the control point:

wherein: (i, j) is a control point; (m, n) are load points; k is the number of leaves; gamma-shaped_nm ^sIs the spanwise vorticity; gamma-shaped_nm ^cChord vortex strength; gamma-shaped_nm ^tWake vortex intensity; gamma-shaped_tipTip vortex strength; gamma-shaped_hubHub vortex strength;

the induction speed of the source system on the control band is as follows:

wherein: q_nmIs the strength of the source sink; k^Q _ijnmkThe influence coefficient of the line source element on the Kth blade is shown; the resultant velocity at the (i, j) th control point in the flow field is:

wherein: k^Q _ijnmkThe influence coefficient of the line source element on the Kth blade is shown; q_nmIs the strength of the source sink;

arranging a plurality of control points on the surface of the initial blade, and performing iterative calculation through the resultant speed obtained by the formula (3) until all the control points on the blade meet the boundary condition of an object plane with the total found speed equal to zero, so as to obtain the final shape of the blade;

the inner pump guide vane is positioned in the hub of the outer pump guide vane and is used for eliminating the circumferential velocity component of water flow and converting the rotary motion of the water flow flowing out of the impeller into axial motion;

the working process is as follows:

rivers get into the pipeline through the water inlet of entry straight tube, through drainage to outer pump impeller room of entry straight tube, engine power output shaft transmits power to outer pump transmission shaft, outer pump transmission shaft drives the blade rotation of outer pump impeller, through the rotatory doing work of outer pump impeller, the pressure energy and the kinetic energy of rivers have obtained the improvement, the circumference velocity component is eliminated through outer pump stator to some rivers, some rivers are through inner pump impeller, do work through the rotation of inner pump impeller, make pressure energy and kinetic energy further improve, the circumference velocity component is eliminated to the rethread inner pump stator, two parts rivers converge in outer pump guide vane room exit, final blowout.

Has the advantages that:

1. the double-duct water jet propulsion pump with the adjustable rotating speed is different from a traditional axial flow type water jet propeller, a parallel structure is adopted in the structure, an inner pump with high rotating speed is embedded in a central flow area of an outer pump, the thrust is obviously improved, the propulsion performance of the double-duct pump is obviously improved under the same inlet area, and the lift is improved under the working condition of small flow.

2. The double-duct water jet propulsion pump with the adjustable rotating speed is different from the traditional multistage water jet propulsion device, can simplify mechanical transmission, respectively allocate the rotating speed, form a brand new basin flow channel, has stronger adaptability under variable working conditions, and can meet navigation requirements under complex working conditions.

3. According to the double-duct water jet propulsion pump with the adjustable rotating speed, the pipeline connection adopts flange connection, the installation is convenient, and the maintenance and repair cost is low.

Drawings

FIG. 1 is a sectional view of a reference plane in front view of a dual-bypass water jet propulsion pump with adjustable rotation speed according to the present invention;

FIG. 2 is a sectional view of a dual-bypass water jet propulsion pump with adjustable rotation speed according to the present invention;

FIG. 3 is a perspective view of a dual bypass water jet propulsion pump with adjustable rotational speed according to the present invention.

The pump comprises an outer pump transmission shaft 1, an inlet straight pipe 2, an outer pump impeller chamber 3, an outer pump impeller 4, an outer pump guide vane chamber 5, an outer pump guide vane 6, an inner pump impeller chamber 7, an axial motor 8, an inner pump impeller 9, an inner pump guide vane chamber 10 and an inner pump guide vane 11.

Detailed Description

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

example 1

As shown in attached figures 1 and 2, the double-duct water jet propulsion pump with the adjustable rotating speed comprises an outer pump transmission shaft 1, an inlet straight pipe 2, an outer pump impeller chamber 3, an outer pump impeller 4, an outer pump guide vane chamber 5, an outer pump guide vane 6, an inner pump impeller chamber 7, an axial motor 8, an inner pump impeller 9, an inner pump guide vane chamber 10 and an inner pump guide vane 11.

The diameter of the outer pump transmission shaft 1 is 68mm, the front end of the outer pump transmission shaft is connected with a power output shaft of an engine, and the rear section of the outer pump transmission shaft is connected with an outer pump impeller;

the inlet straight pipe 2 is an equivalent section pipeline, is connected with the outer pump impeller chamber through a flange plate and is connected with a water inlet flow channel fixed on a ship through a flange;

as shown in fig. 3, the outer pump impeller chamber 3 is of an equal-diameter cylinder structure, the inner diameter is 304.8mm, the wall thickness is 8mm, flange plates are arranged at two ends, 8 holes with the diameter of 18mm are uniformly distributed, the right side of the outer pump impeller chamber 3 is connected with the inlet straight pipe 2 through a bolt, and the left side of the outer pump impeller chamber 3 is connected with the outer pump guide vane chamber 5 through a bolt;

the outer pump impeller 4 is a main acting part, the diameter of the impeller is 304.3mm, the blade top gap is 0.5mm, the number of blades is 5, the rotating speed is 1000rpm, the outer pump impeller is positioned in the outer pump impeller chamber 3, mechanical energy input by the outer pump transmission shaft 1 is converted into energy of fluid, the blades are fixed on a hub through nuts and positioning pins, and the hub is fixedly connected with the outer pump transmission shaft 1;

the outer pump guide vane chamber 5 is of an equal-diameter cylinder structure, the inner diameter is 304.8mm, the wall thickness is 8mm, flange plates are arranged at two ends of the outer pump guide vane chamber, 8 holes with the diameter of 18mm are uniformly distributed, the right side of the outer pump guide vane chamber 5 is connected with the outer pump vane chamber 3 through bolts, and a flange plate is arranged at the outlet end and can be connected with a nozzle section; (ii) a

The outer pump guide vanes 6 are positioned in the outer pump guide vane chamber 5 and integrated with the outer pump guide vane chamber, the number of the guide vanes is 8, the guide vanes are used for eliminating the circumferential velocity component of water flow, and the hubs of the outer pump guide vanes 6 are of hollow structures and used for arranging inner pump impellers 9 and inner pump guide vanes 11;

the inner pump impeller 9 is an acting part, the diameter of the impeller is 149.5mm, the blade top gap is 0.25mm, the number of blades is 6, the rotating speed is 1450rpm, the inner pump impeller is arranged in the hub of the outer pump guide vane 6 and is driven by a driving shaft through an axial motor 8 arranged in the hub of the outer pump guide vane 6 to drive the inner pump impeller 9 to rotate, and the position of the axial motor is shown in fig. 2 and 3;

designing an inner pump blade based on a discrete vortex lattice method; under the condition of giving radial and chordwise distribution of the ring vector, a singular point system is arranged on the surface of the initial blade, iterative calculation is carried out by the singular point system until the boundary condition of the object plane of the blade arch cambered surface is met, the final shape of the blade arch cambered surface is further determined, and the initial shape of the blade is finally determined.

Firstly, dividing M intervals on an initial surface along a radial direction, and dividing N grids along a chord direction; then, arranging a control point at the core of each grid, arranging a line source and a spanwise vortex at 1/4 chord lengths, arranging a chordwise vortex on a chordwise connecting line of the spanwise vortex end point, and setting the induced velocity of a vortex system on the control point:

wherein: (i, j) is a control point; (m, n) is a load point; k is the number of leaves; gamma-shaped_nm ^sIs the spanwise vorticity; gamma-shaped_nm ^cChord vortex strength; gamma-shaped_nm ^tWake vortex intensity; gamma-shaped_tipTip vortex strength; gamma-shaped_hubHub vortex strength;

the induction speed of the source system on the control band is as follows:

wherein: q_nmIs the strength of the source sink; k^Q _ijnmkThe influence coefficient of the line source element on the Kth blade is shown; the resultant velocity at the (i, j) th control point in the flow field is:

wherein: k^Q _ijnmkThe influence coefficient of the line source element on the Kth blade is shown; q_nmIs the strength of the source sink;

performing iterative computation on the singularity system according to the blade section as an initial surface until all control points on the blade meet the boundary condition of an object plane with the total found speed equal to zero, and obtaining the final shape of the blade, wherein the final shape is shown in table 1;

TABLE 1 basic parameters of dual-duct impeller in propeller pump

The inner pump guide vanes 11 are positioned inside the hub of the outer pump guide vanes 6, the number of the guide vanes is 8, and the guide vanes are used for eliminating the circumferential velocity component of water flow;

the specific working process is as follows:

rivers pass through the water inlet and get into water jet propulsion ware, through the drainage of entry straight tube 2 to outer pump impeller chamber 3, engine power output shaft is with power transmission to outer pump transmission shaft 1, outer pump transmission shaft 1 drives the blade rotation of outer pump impeller 4, through the rotatory work of outer pump impeller 4, the pressure energy and the kinetic energy of rivers have obtained the improvement, the circumferential velocity component is eliminated through outer pump stator 6 to some rivers, some rivers are through inner pump impeller 9, the rotatory work of doing through inner pump impeller 9, make pressure energy and kinetic energy further improve, the circumferential velocity component is eliminated to the rectification of rethread inner pump stator 11, two parts rivers converge in outer pump stator chamber 5 exit, final blowout.

The numerical calculation verifies that under the design working condition, the lift of a double-duct water jet propulsion pump is not adopted and is 11.5m, the necessary cavitation allowance is 8.15m, the double-duct water jet propulsion pump is 13.2m, the necessary cavitation allowance is 7.8m, the lift size is obviously improved, and the cavitation resistance is obviously improved.

The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.