CN103963948B - Method for designing efficient duct - Google Patents

Abstract

The invention discloses a method for designing an efficient duct and relates to the field of designing of a ship propelling system. Ducted propellers are applied to ships with heavy loads more and more widely. A duct is one of key components of the ducted propeller. The research direction can be that the efficient ducts are found, so that the method for designing the efficient duct is provided and based on a duct parameterization expressing method. According to the efficient duct designing method, the linetype of the duct is expressed in a parameterized mode, and the efficient duct is designed according to a CFD calculation method. By the adoption of the method for designing the efficient duct, the efficient duct can be conveniently and rapidly designed.

Description

A kind of efficient catheter design method

Technical field

The present invention relates to marine propuision system design field, especially a kind of method for designing of propeller nozzle.

Background technology

Ducted propeller is a kind of driving tool of ship, refers to add conduit around screw, just becomes conduit spiral shell Rotation oar.At present, application on the ship of heavy load for the ducted propeller is more and more extensive.

Conduit is a kind of part of the fixation installed in the periphery of screw, and the axial cross section of catheter wall is in airfoil, the wing The inner face convex surface facing conduit of shape, the circular edge of its front end towards the direction of motion, using conduit, thus it is possible to vary by spiral The fluid velocity of oar.

Conduit, as one of the critical component of all-direction propeller, directly affects the efficiency of all-direction propeller, especially It is the efficiency of moored condition.Conduit the more commonly used at present is No.19A conduit etc., and the expression way for conduit does not also have at present There is formation Parameter Expression, the method for designing simultaneously also not forming effectively efficiently conduit is it is impossible to make all-direction propeller reach To highest efficiency.Therefore, seek the research direction that efficient conduit has become following.

Content of the invention

The applicant is directed to the problems referred to above and technical need it is proposed that a kind of efficient based on conduit Parameter Expression method Catheter design method.Efficient conduit can quickly and easily be designed using this method.

Technical scheme is as follows：

A kind of efficient catheter design method, comprises the steps：

1) conduit line style is divided into catheter inside surface and catheter outer surface, wherein catheter inside surface be divided into duct inlet section, Conduit interlude and conduit outlet section；Define P0 (x0, y0), P1 (x1, y1), P2 (x2, y2), P3 (x3, y3), P4 (x4, Y4), P5 (x5, y5), seven control points of P6 (x6, y6)；Catheter inside surface is by 5 points of controls of P0, P6, P1, P2, P3, wherein conduit , by 3 points of controls of P0, P6, P1, by 2 points of controls of P1, P2, conduit outlet section is by 2 points of controls of P2, P3 for conduit interlude for inducer； Catheter outer surface is by 3 points of controls of P0, P5, P4；Define control point P1, P2, P3, P4, P5, P6 slope be respectively k1, k2, k3, k4、k5、k6；

2) duct inlet area coefficient Ain, conduit outlet area coefficient Aout, rounding radius RLE and with radius of circle are defined RTE；Conduit guide margin curveFor one section of arc length of guide margin rounding, wherein rounding initial point is defined as O (RLE, y0), controls The angle of point P0 and P5 is α=90 degree, and the angle of control point P0 and P6 is β=45 degree；Conduit draw ratio is 0.5, defines spiral Oar radius R=1, then catheter length L is 1,

3) seven control points P0, P1, P2, P3, P4, P5, P6 are defined respectively as：

P0:X0=0,

P1:X1=0.4, y1=0；

P2:X2=0.6, y2=0；

P3:X3=1.0,

P4:X4=1, y4=y3+RTE × 2；

P5:X5=RLE (1-cos α), y5=y0+RLE sin α；

P6:X6=RLE (1-cos β), y6=y0-RLE sin β；

4) slope k 1, k2, k3, k4, k5, k6 are defined respectively as：

K1=k2=0；

K5=k4 or k5=0；

K6=-tan β；

5) removeCurve adopts rounding part arc length to constitute, and other conduit sections curves are all using three times Hermite interpolation method is constituted；Conduit sectional line style expression formula is：

Catheter outer surface：

f_out2=Hermite (P4, P5, k4, k5, x) (x5<x≤1.0)；

Catheter inside surface：

f_in2=Hermite (P6, P1, k6, k1, x) (x6<x≤x1)；

f_in3=Hermite (P1, P2, k1, k2, x) (x1<x≤x2)；

f_in4=Hermite (P2, P3, k2, k3, x) (x2<x≤1.0)；

6) CFD computational methods are adopted to design conduit line style；

7) the line style expression formula according to conduit section, by duct inlet area coefficient Ain, conduit outlet area coefficient Aout, rounding radius RLE and the conduit line style generating design with tetra- parameters of radius of circle RTE；

8) performance evaluation is carried out to the conduit generating, if efficient conduit then terminates to design；Otherwise adjusting parameter is again Generate conduit line style, until obtaining efficient conduit.

The method have the benefit that：

Present invention employs Parameter Expression conduit line style, and come using CFD (computational fluid dynamics) computational methods Design efficient conduit, computational efficiency is high, be a kind of simple, efficiently efficient catheter design method.

Brief description

Fig. 1 is conduit sectional line style control point schematic diagram.

Fig. 2 is given inlet -duct area coefficient, parameterizes the conduit sectional line style of generation under different discharge area coefficients.

Fig. 3 is given discharge area coefficient, parameterizes the conduit sectional line style of generation under different inlet -duct area coefficients.

Fig. 4 is the design cycle of efficient conduit.

Specific embodiment

Below in conjunction with the accompanying drawings the specific embodiment of the present invention is described further.

As shown in figure 1, conduit line style is divided into catheter inside surface and catheter outer surface, wherein catheter inside surface is divided into conduit to enter Mouth section, conduit interlude and conduit outlet section.In order to become more meticulous expression conduit line style, altogether adopt P0 (x0, y0), P1 (x1, Y1), P2 (x2, y2), P3 (x3, y3), P4 (x4, y4), P5 (x5, y5) and seven control points of P6 (x6, y6).Wherein table in conduit Face amounts to 5 points by P0, P6, P1, P2, P3 and controls, and catheter outer surface is by 3 points of controls of P0, P5 and P4.P1、P2、P3、P4、 The slope at P5, P6 control point is respectively k1, k2, k3, k4, k5, k6.

Using duct inlet area coefficient Ain, conduit outlet area coefficient Aout, rounding radius RLE and with radius of circle RTE To determine the control point near conduit guide margin and conduit lagging edge.Conduit guide margin curveOne section of arc for guide margin rounding Long, the angle that wherein rounding initial point is defined as O (RLE, y0), P0 and P5 is α=90 degree, and the angle of P0 and P6 is β=45 degree.Remove ?Curve adopts rounding part arc length to constitute, and other conduit sections curves are all using three Hermites (Hermite) interpolation method.Conduit draw ratio is 0.5, defines propeller radius R=1, then catheter length L is 1,7 control points It is defined as follows：

P0:X0=0,

P1:X1=0.4, y1=0；

P2:X2=0.6, y2=0；

P3:X3=1.0,

P4:X4=1, y4=y3+RTE × 2；

P5:X5=RLE (1-cos α), y5=y0+RLE sin α；

P6:X6=RLE (1-cos β), y6=y0-RLE sin β；

K1, k2, k3, k4, k5, k6 are defined as follows：

K1=k2=0；

K5=k4 or k5=0；

K6=-tan β；

Conduit sectional line style expression formula can be expressed as：

Catheter outer surface：

f_out2=Hermite (P4, P5, k4, k5, x) (x5<x≤1.0)；

Catheter inside surface：

f_in2=Hermite (P6, P1, k6, k1, x) (x6<x≤x1)；

f_in3=Hermite (P1, P2, k1, k2, x) (x1<x≤x2)；

f_in4=Hermite (P2, P3, k2, k3, x) (x2<x≤1.0)；

According to the line style expression formula of conduit section, the parameter forming conduit sectional line style is duct inlet area system Number Ain, conduit outlet area coefficient Aout, rounding radius RLE and with radius of circle RTE.

Fig. 2 and Fig. 3 is the catheter design example using the present invention.Wherein, Fig. 2 is given inlet -duct area coefficient, and difference goes out The conduit sectional line style of generation is parameterized under open area coefficient.Fig. 3 is given discharge area coefficient, under different inlet -duct area coefficients The conduit sectional line style that parametrization generates.

Fig. 4 gives the design cycle of the efficient conduit based on conduit Parameter Expression method.In the parameter obtaining conduit After changing expression, design conduit line style using existing CFD computational methods, and pass through duct inlet area coefficient Ain, conduit outlet Area coefficient Aout, rounding radius RLE and the conduit line style generating design with tetra- parameters of radius of circle RTE.Subsequently to generation Conduit carries out performance evaluation, if efficient conduit then terminates to design；Otherwise adjusting parameter regenerates conduit line style, until To efficient conduit.

Above-described is only the preferred embodiment of the present invention, the invention is not restricted to above example.It is appreciated that this Skilled person directly derive without departing from the spirit and concept in the present invention or associate other improve and become Change, be all considered as being included within protection scope of the present invention.

Claims (1)

1. a kind of efficient catheter design method is it is characterised in that comprise the steps：

1) conduit line style is divided into catheter inside surface and catheter outer surface, wherein catheter inside surface is divided into duct inlet section, conduit Interlude and conduit outlet section；Define P0 (x0, y0), P1 (x1, y1), P2 (x2, y2), P3 (x3, y3), P4 (x4, y4), P5 (x5, y5), seven control points of P6 (x6, y6)；Catheter inside surface is by 5 points of controls of P0, P6, P1, P2, P3, wherein duct inlet section By 3 points of controls of P0, P6, P1, by 2 points of controls of P1, P2, conduit outlet section is by 2 points of controls of P2, P3 for conduit interlude；Outside conduit Surface is by 3 points of controls of P0, P5, P4；Define control point P1, P2, P3, P4, P5, P6 slope be respectively k1, k2, k3, k4, k5, k6；

2) duct inlet area coefficient Ain, conduit outlet area coefficient Aout, rounding radius RLE and with radius of circle RTE are defined； Conduit guide margin curveFor one section of arc length of guide margin rounding, wherein rounding initial point is defined as O (RLE, y0), control point P0 Angle with P5 is α=90 degree, and the angle of control point P0 and P6 is β=45 degree；Conduit draw ratio is 0.5, defines screw half Footpath R=1, then catheter length L is 1；

3) seven control points P0, P1, P2, P3, P4, P5, P6 are defined respectively as：

P1:X1=0.4, y1=0；

P2:X2=0.6, y2=0；

P4:X4=1, y4=y3+RTE × 2；

P5:X5=RLE (1-cos α), y5=y0+RLE sin α；

P6:X6=RLE (1-cos β), y6=y0-RLE sin β；

4) slope k 1, k2, k3, k4, k5, k6 are defined respectively as：

K1=k2=0；

K5=k4ork5=0；

K6=-tan β；

5) removeCurve adopts rounding part arc length to constitute, and other conduit sections curves are all using cubic Hamiltonian symmetrical systems Method is constituted；Conduit sectional line style expression formula is：

Catheter outer surface：

Wherein, 0≤x≤x5；

f_out2=Hermite (P4, P5, k4, k5, x), wherein, x5≤x≤1.0；

Catheter inside surface：

Wherein, 0≤x≤x6；

f_in2=Hermite (P6, P1, k6, k1, x), wherein, x6≤x≤x1；

f_in3=Hermite (P1, P2, k1, k2, x), wherein, x1≤x≤x2；

f_in4=Hermite (P2, P3, k2, k3, x), wherein, x2≤x≤1.0；

6) CFD computational methods are adopted to design conduit line style；

7) the line style expression formula according to conduit section, by duct inlet area coefficient Ain, conduit outlet area coefficient Aout, Rounding radius RLE and the conduit line style generating design with tetra- parameters of radius of circle RTE；

8) performance evaluation being carried out to the conduit generating, if being so that all-direction propeller reaches the conduit of peak efficiency, tying Bundle design；Otherwise adjusting parameter regenerates conduit line style, until obtaining so that all-direction propeller reaches leading of peak efficiency Pipe.