CN102930118B - A kind of optimization design method for blade root of compound propeller blade - Google Patents

Abstract

A kind of optimization design method for blade root of compound propeller blade, it relates to a kind of blade root Optimization Design, is specifically related to a kind of optimization design method for blade root of compound propeller blade.The present invention is in order to solve the blade root fastenings form of traditional design method design, and when being applied in naval vessels screw propeller, between adjacent blades, profile often exists overlapping phenomenon, and hub diameter is relatively little, causes blade and propeller hub can not meet the problem of request for utilization.The present invention is by the geometric model of 3D solid configuration Software on Drawing composite propeller, RANS equation is utilized to calculate the hydrodynamic performance of composite propeller, and then build the geometric model of the composite propeller leaf containing wedge shape blade root, calculated the stress distribution of blade and blade root by finite element analysis software, finally complete the optimal design of blade root.The present invention is used for the means of transports such as naval vessels.

Description

A kind of optimization design method for blade root of compound propeller blade

Technical field

The present invention relates to a kind of blade root Optimization Design, be specifically related to a kind of optimization design method for blade root of compound propeller blade.

Background technology

Composite propeller, as a kind of novel naval vessels screw propeller, has the features such as lightweight, efficient, low vibration, low noise, seawater corrosion resistance and easy-maintaining, is day by day subject to the favor of naval vessels Design of Propeller person this year.Usually, composite propeller comprises composite material blade and metal propeller hub two parts, and is fixed on propeller hub by blade by blade root.The dynamic loading that blade is all and static load are all delivered on propeller hub by blade root, thus blade root is the position that blade stress is the most complicated, also be the difficult point of composite material blade design, should ensure during design to be connected firmly under any service condition, make every effort to manufacture simple, easy to assembly simultaneously.

At present, the type of attachment that composite material blade blade root adopts has the connection of flange flange bolt, staight shank axis tile connects, inverted-cone connects, ear inserts bolt connection etc., above-mentioned connected mode is used for the sleeve configuration composite structures such as composite machine wing blade, composite wind turbine blade, for naval vessels screw propeller, especially seven leaves of low noise or nine leaf highly skewed propellers, between adjacent blades often there is overlapping phenomenon in profile, and hub diameter is relatively little, adopt traditional blade root fastenings form, blade and propeller hub are not well positioned to meet design request for utilization.Based on the above, the patent of invention that publication number is CN101706833A, publication date is on May 12nd, 2010 discloses a kind of method for designing of marine propeller made of carbon fiber composite material, but in the document and the unexposed design procedure how simplifying screw propeller, reduce development cost, and how to extend the military service cycle of composite propeller.

Summary of the invention

The present invention is for solving existing Design Method of Propeller complex steps, and development cost is higher, the problem that the cycle is short and the composite propeller be designed to is on active service, and then proposes a kind of optimization design method for blade root of compound propeller blade.

The present invention is the technical scheme taked that solves the problem: concrete steps of the present invention are:

Step one, the end face diameter of propeller hub and basal diameter doubly to be increased with m simultaneously;

Step 2, composite material blade to be evenly arranged on the propeller hub after increase, and to use the geometric model of 3D solid configuration Software on Drawing composite propeller;

Step 3, the geometric model of composite propeller is imported the front processor GAMBIT of Fluid Mechanics Computation analysis software, set up fluid domain, dividing flow volume mesh, build hydrodynamic model;

Step 4, on the Calculation of Hydrodynamic model basis built, the computational fluid dynamics method based on RANS equation is utilized to calculate the hydrodynamic performance of composite propeller,

Wherein RANS equation is:

$\frac{\∂}{\∂t}\left({\mathrm{\ρu}}_i\right)+\frac{\∂}{{\∂x}_j}\left({\mathrm{\ρu}}_i{u}_j\right)=-\frac{\∂p}{{\∂x}_i}+\frac{\∂}{{\∂x}_j}(\mathrm{\μ}\frac{{\∂u}_i}{{\∂x}_j}-\mathrm{\ρ}\stackrel{\‾}{u_i^{\′}{u}_j^{\′}})+S_i---\left(1\right),$

In formula (1), u is the velocity under cartesian coordinate system, and ρ is fluid density, and p is static pressure, and μ is the dynamic viscosity coefficient of fluid, reynolds stress item, S _irepresent source item,

The hydrodynamic performance of composite propeller comprises thrust coefficient, torque coefficient and efficiency:

Thrust coefficient K _t=T/ ρ n ²d ⁴,

Torque coefficient K _q=Q/ ρ n ²d ⁵,

Efficiency eta=JK _t/ 2 π K _q,

Wherein ρ represents fluid density, n represents revolution speed of propeller, D represents the composite propeller diameter after propeller hub adjustment, J represents advance coefficient J=0.2, T represent the thrust that screw propeller produces, Q represent the moment of torsion suffered by screw propeller obtain and derive low enter speed time act on pressure on composite material blade;

Step 5, increase the primary design of large diameter propeller hub carrying out the wedge shape blade root of composite material blade, determine the initial value of leading the outer lead angle θ that fillet Φ and blade root are connected with composite material blade of the length a in composite material blade wedge shape blade root cross section, width b, the wedge shape section back taper angle ω of wedge shape blade root, wedge shape blade root and propeller hub junction;

Step 6, primary design value according to wedge shape blade root in the geometry offset of composite propeller and step 5, utilize 3D solid configuration software building containing the geometric model of the composite material blade of wedge shape blade root;

Step 7, will to import in FEM-software ANSYS containing the geometric model of the composite material blade of wedge shape blade root in step 6, choose cell type SOLID46 and stress and strain model is carried out to it, definition elastic constant, Poisson ratio, wherein elastic constant EX=1.1e11Pa, EY=EZ=8.97e9Pa, Poisson ratio is 0.34, and modulus of shearing is 3.9e9Pa, selected ply stacking-sequence is the ply sequence of composite material blade, and ply stacking-sequence is build the finite element model of the composite material blade containing wedge shape blade root;

Step 8, based on the finite element model of step composite material blade wherein, by the length a of the wedge shape section of wedge shape blade root, the wedge shape section back taper angle ω of width b and wedge shape blade root is defined as design variable, according to the value range of selected hub diameter determination design variable, using the stress of wedge shape blade root and propeller shank junction as objective function, using the blade pressure that obtains in step 4 as load-up condition, FEM-software ANSYS is utilized to carry out the objective optimization design of blade root, namely the stress distribution situation of composite material blade and blade root under different designs variable is calculated, Stress calculation is completed by finite element analysis software,

Step 9, by comparing with the ultimate strength of material system, whether the wedge shape blade root of test design meets strength of joint requirement, finite element software is utilized to obtain the stress value of blade and each node of propeller hub, then the limit strength values of these stress values and selected materials system is compared, as being less than limit strength values, then meet the demands, as being more than or equal to limit strength of joint, then do not meet, be back to step one and readjust hub diameter and each geometric element of wedge shape blade root, until the geometric configuration of the wedge shape blade root of design meets strength of joint requirement, namely the optimal design of composite propeller blade root is completed.

The invention has the beneficial effects as follows: the composite propeller blade root designed by the present invention, can be good at realizing the transmission of the dynamic and static load of blade to propeller hub, and be connected firmly, manufacture simple, easy to assembly.Compared with prior art, this method for designing is simple, greatly can reduce the development cost of composite propeller, can meet the actual operation requirements of composite propeller, is conducive to the military service cycle extending composite propeller, replacing for convenience detach.

Accompanying drawing explanation

Fig. 1 is the cross sectional representation of blade root, and Fig. 2 is the schematic cross-section that blade root is connected with propeller hub.

Embodiment

Embodiment one: composition graphs 1 and Fig. 2 illustrate present embodiment, described in present embodiment, a kind of concrete steps of blade root of compound propeller blade method for designing are as follows:

Step one, the end face diameter of propeller hub and basal diameter doubly to be increased with m simultaneously;

Step 2, composite material blade to be evenly arranged on the propeller hub after increase, and to use the geometric model of 3D solid configuration Software on Drawing composite propeller;

Step 3, the geometric model of composite propeller is imported the front processor GAMBIT of Fluid Mechanics Computation analysis software, set up fluid domain, dividing flow volume mesh, build hydrodynamic model;

Step 4, on the Calculation of Hydrodynamic model basis built, the computational fluid dynamics method based on RANS equation is utilized to calculate the hydrodynamic performance of composite propeller,

Wherein RANS equation is:

$\frac{\∂}{\∂t}\left({\mathrm{\ρu}}_i\right)+\frac{\∂}{{\∂x}_j}\left({\mathrm{\ρu}}_i{u}_j\right)=-\frac{\∂p}{{\∂x}_i}+\frac{\∂}{{\∂x}_j}(\mathrm{\μ}\frac{{\∂u}_i}{{\∂x}_j}-\mathrm{\ρ}\stackrel{\‾}{u_i^{\′}{u}_j^{\′}})+S_i---\left(1\right),$

In formula (1), u is the velocity under cartesian coordinate system, and ρ is fluid density, and p is static pressure, and μ is the dynamic viscosity coefficient of fluid, reynolds stress item, S _irepresent source item,

The hydrodynamic performance of composite propeller comprises thrust coefficient, torque coefficient and efficiency:

Thrust coefficient K _t=T/ ρ n ²d ⁴,

Torque coefficient K _q=Q/ ρ n ²d ⁵,

Efficiency eta=JK _t/ 2 π K _q,

Wherein ρ represents fluid density, n represents revolution speed of propeller, D represents the composite propeller diameter after propeller hub adjustment, J represents advance coefficient J=0.2, T represent the thrust that screw propeller produces, Q represent the moment of torsion suffered by screw propeller obtain and derive low enter speed time act on pressure on composite material blade;

Step 5, increase the primary design of large diameter propeller hub carrying out the wedge shape blade root of composite material blade, determine the initial value of leading the outer lead angle θ that fillet Φ and blade root are connected with composite material blade of the length a in composite material blade wedge shape blade root cross section, width b, the wedge shape section back taper angle ω of wedge shape blade root, wedge shape blade root and propeller hub junction;

Step 6, primary design value according to wedge shape blade root in the geometry offset of composite propeller and step 5, utilize 3D solid configuration software building containing the geometric model of the composite material blade of wedge shape blade root;

Step 7, will to import in FEM-software ANSYS containing the geometric model of the composite material blade of wedge shape blade root in step 6, choose cell type SOLID46 and stress and strain model is carried out to it, definition elastic constant, Poisson ratio, wherein elastic constant EX=1.1e11Pa, EY=EZ=8.97e9Pa, Poisson ratio is 0.34, and modulus of shearing is 3.9e9Pa, selected ply stacking-sequence is the ply sequence of composite material blade, and ply stacking-sequence is build the finite element model of the composite material blade containing wedge shape blade root;

Step 8, based on the finite element model of step composite material blade wherein, by the length a of the wedge shape section of wedge shape blade root, the wedge shape section back taper angle ω of width b and wedge shape blade root is defined as design variable, according to the value range of selected hub diameter determination design variable, using the stress of wedge shape blade root and propeller shank junction as objective function, using the blade pressure that obtains in step 4 as load-up condition, FEM-software ANSYS is utilized to carry out the objective optimization design of blade root, namely the stress distribution situation of composite material blade and blade root under different designs variable is calculated, Stress calculation is completed by finite element analysis software,

Step 9, by comparing with the ultimate strength of material system, whether the wedge shape blade root of test design meets strength of joint requirement, finite element software is utilized to obtain the stress value of blade and each node of propeller hub, then the limit strength values of these stress values and selected materials system is compared, as being less than limit strength values, then meet the demands, as being more than or equal to limit strength of joint, then do not meet, be back to step one and readjust hub diameter and each geometric element of wedge shape blade root, until the geometric configuration of the wedge shape blade root of design meets strength of joint requirement, namely the optimal design of composite propeller blade root is completed.

In present embodiment, flow dynamics analysis software is the CFX flow dynamics analysis software that Britain AEATechnology develops, finite element software refers to ANSYS finite element analysis software, 3D solid configuration software refers to the UG 3D solid configuration software that EDS company of the U.S. develops, RANS equation refers to Reynolds Nevier-Stokes equation, in the step 7 of present embodiment 0 ° of direction represents the line direction at propeller hub axle center and blade tip place, and 2 represent that laying is two-layer, and S represents symmetrical laying.

Embodiment two: composition graphs 1 and Fig. 2 illustrate present embodiment, the m=1.05 in the step one of a kind of optimization design method for blade root of compound propeller blade described in present embodiment, 1.1,1.15,1.2.Other composition and annexation identical with embodiment one.

Claims (1)

1. an optimization design method for blade root of compound propeller blade, is characterized in that: the concrete steps of described a kind of blade root of compound propeller blade method for designing are as follows:

Step one, the end face diameter of propeller hub and basal diameter doubly to be increased with m simultaneously, m=1.05,1.1,1.15,1.2;

Step 2, composite material blade to be evenly arranged on the propeller hub after increase, and to use the geometric model of 3D solid configuration Software on Drawing composite propeller;

Step 3, the geometric model of composite propeller is imported the front processor GAMBIT of Fluid Mechanics Computation analysis software, set up fluid domain, dividing flow volume mesh, build hydrodynamic model;

Step 4, on the Calculation of Hydrodynamic model basis built, the computational fluid dynamics method based on RANS equation is utilized to calculate the hydrodynamic performance of composite propeller,

Wherein RANS equation is:

$\frac{\∂}{\∂t}\left(\mathrm{\ρ}{u}_i\right)+\frac{\∂}{\∂x_j}\left(\mathrm{\ρ}{u}_i{u}_j\right)=-\frac{\∂p}{\∂x_i}+\frac{\∂}{\∂x_j}(\mathrm{\μ}\frac{\∂u_i}{\∂x_j}-\mathrm{\ρ}\stackrel{\‾}{u_i^{\′}{u}_j^{\′}})+S_i---\left(1\right),$

In formula (1), u is the velocity under cartesian coordinate system, and ρ is fluid density, and p is static pressure, and μ is the dynamic viscosity coefficient of fluid, reynolds stress item, S _irepresent source item,

The hydrodynamic performance of composite propeller comprises thrust coefficient, torque coefficient and efficiency:

Thrust coefficient K _t=T/ ρ n ²d ⁴,

Torque coefficient K _q=Q/ ρ n ²d ⁵,

Efficiency eta=JK _t/ 2 π K _q,

Wherein ρ represents fluid density, n represents revolution speed of propeller, D represents the composite propeller diameter after propeller hub adjustment, J represents advance coefficient J=0.2, T represent the thrust that screw propeller produces, Q represent the moment of torsion suffered by screw propeller obtain and derive low enter speed time act on pressure on composite material blade;

Step 5, increase the primary design of large diameter propeller hub carrying out the wedge shape blade root of composite material blade, determine the initial value of leading the outer lead angle θ that fillet Φ and blade root are connected with composite material blade of the length a in composite material blade wedge shape blade root cross section, width b, the wedge shape section back taper angle ω of wedge shape blade root, wedge shape blade root and propeller hub junction;

Step 6, primary design value according to wedge shape blade root in the geometry offset of composite propeller and step 5, utilize 3D solid configuration software building containing the geometric model of the composite material blade of wedge shape blade root;

Step 7, will to import in FEM-software ANSYS containing the geometric model of the composite material blade of wedge shape blade root in step 6, choose cell type SOLID46 and stress and strain model is carried out to it, definition elastic constant, Poisson ratio, wherein elastic constant EX=1.1e11Pa, EY=EZ=8.97e9Pa, Poisson ratio is 0.34, and modulus of shearing is 3.9e9Pa, selected ply stacking-sequence is the ply sequence of composite material blade, and ply stacking-sequence is build the finite element model of the composite material blade containing wedge shape blade root;

Step 8, based on the finite element model of step composite material blade wherein, by the length a of the wedge shape section of wedge shape blade root, the wedge shape section back taper angle ω of width b and wedge shape blade root is defined as design variable, according to the value range of selected hub diameter determination design variable, using the stress of wedge shape blade root and propeller shank junction as objective function, using the blade pressure that obtains in step 4 as load-up condition, FEM-software ANSYS is utilized to carry out the objective optimization design of blade root, namely the stress distribution situation of composite material blade and blade root under different designs variable is calculated, Stress calculation is completed by finite element analysis software,

Step 9, by comparing with the ultimate strength of material system, whether the wedge shape blade root of test design meets strength of joint requirement, finite element software is utilized to obtain the stress value of blade and each node of propeller hub, then the limit strength values of these stress values and selected materials system is compared, as being less than limit strength values, then meet the demands, as being more than or equal to limit strength of joint, then do not meet, be back to step one and readjust hub diameter and each geometric element of wedge shape blade root, until the geometric configuration of the wedge shape blade root of design meets strength of joint requirement, namely the optimal design of composite propeller blade root is completed.