CN106383930A - Multiple fluid-solid coupling calculation method for tail bearing-rotor system - Google Patents

Abstract

The invention discloses a multiple fluid-solid coupling calculation method for a tail bearing-rotor system, and belongs to the technical field of fluid-solid coupling of ocean platforms. The method involves a plurality of tail bearings and a propeller shaft, and comprises the steps of setting a step length of unit time and total calculation time, discretizing a fluid domain unit, discretizing a solid domain unit, calculating a discretized fluid domain, calculating a discretized solid domain, performing data coupling calculation, and ending the calculation. According to the multiple fluid-solid coupling calculation method for the tail bearing-rotor system, accurate simulation of a working process of the tail bearing and rotor system is realized, and the problem of low fluid domain calculation precision caused by excessively large mesh distortion in application of an existing dynamic mesh technique to spatial regions occupied by the tail bearings to perform numerical simulation is solved; and multiple fluid-solid coupling calculation is realized, the defects of coupling calculation of a symmetric bearing-rotor system are overcome, and multiple coupling effects, between vibration and lubrication, of the propeller shaft and the tail bearings can be accurately simulated.

Description

A kind of multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system

Technical field

A kind of multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system, belongs to ocean platform fluid structurecoupling technical field.

Background technology

With oil investigation, investigation and prospecting center of gravity gradually from land, shallow sea steering deep-sea, the application of ocean platform is constantly expanded Greatly.Ocean platform is divided into fixed, movable and semi-fixed type by architectural feature and working condition.Screw is that ocean is floating type One of critical component of platform, ocean floating platform relies on the buoyancy of itself to support its platform weight, and by screw Dynamic positioning platform, propeller shaft is the tailing axle of the argosy system with complicated shafting, supports fortune by the tail bearing of ship afterbody OK, it runs the reaction force opposing wind producing, wave, the active force such as stream, reaches balance positioning purpose it is ensured that ocean floating platform Can long period safety and stability operation.Therefore, study the fluid and structural simulation method of asymmetric drift tail bearing-rotor-support-foundation system off field Significant to ocean platform long period trouble free service；At present, the tail bearing major part of China's propeller shafting use is By introduction of foreign technology or copy external product to be produced, autonomous Design power is not strong, multi- scenarios method operation process simulation Simultaneously there are various problems it is impossible to develop the boat of the deep sea drilling floating platform with autonomous property right for China's depth in weak foundation Row provides technical support with positioning power system.

In realizing process of the present invention, inventor finds at least there is problems with prior art：1st, tail bearing and spiral shell The Working Process of rotation oar axle system is inaccurate；2nd, tail bearing-rotor-support-foundation system carries out the fluid during fluid structurecoupling Domain computational accuracy is low；3rd, tail bearing-rotor-support-foundation system cannot accurately disclose propeller shaft and multiple tails during carrying out fluid structurecoupling Coupling mechanism between vibration, lubrication for the bearing.

Find that through analysis being primarily due to of the problems referred to above occurs：

1st, the large-scale CAE software of existing fluid structurecoupling technology application, enters to the discretization data of fluid domain and solid domain Row unified calculation is processed, and leads to tail bearing inaccurate with the Working Process of propeller shaft system；

2nd, existing fluid domain calculates and is applied to tail bearing numerical simulation using Dynamic mesh to there is mesh distortion excessive Problem；

3rd, in propeller shafting, propeller shaft is supported jointly by multiple tail bearings, has very strong between each tail bearing Coupled relation, the change of working condition between rotor-support-foundation system and a tail bearing influences whether the working condition of adjacent tail bearing, The lubrication working condition of each tail bearing interacts, influences each other；Therefore, tail bearing will with the calculating process that couples of propeller shaft Different from the calculating of symmetrical Rotor-Bearing System, need to consider the asymmetry between each tail bearing, realize fluid-fluid- The multiple coupling of solid calculates.

Content of the invention

The technical problem to be solved in the present invention is：Overcome the deficiencies in the prior art, provide a kind of accurate simulation tail bearing with The rotor-support-foundation system course of work, the fluid domain computational accuracy that improves, accurate simulation propeller shaft and multiple tail bearing coupling mechanism Tail bearing-rotor-support-foundation system multiple fluid and structural simulation method.

The technical solution adopted for the present invention to solve the technical problems is：This multiple fluid structurecoupling of tail bearing-rotor-support-foundation system Computational methods, including multiple tail bearings, a propeller shaft, further comprising the steps of：

The setting of unit interval step-length and the total time setting calculating；

Fluid domain cell discretization, the cell discretization of the area of space that multiple tail bearings occupy；

Solid domain cell discretization, the cell discretization of propeller shaft rotor dynamics equation；

The calculating of discretization fluid domain, updates discretization fluid domain grid node using structuring dynamic mesh update method, And obtain fluid matasomatism in the borderline Nonlinear Oil-Film Forces of Sliding of propeller shaft；

The calculating of discretization solid domain, solves propeller shaft rotor dynamics equation using time-domain integration method, obtains spiral Displacement and center at oar axle journal；

Data coupling calculates, in unit interval step-length, using multiple described Nonlinear Oil-Film Forces of Slidings as discretization solid domain Boundary condition, is input to discretization solid domain and is calculated；In same time step, by displacement and centre bit at screw axle journal Put, the grid as discretization fluid domain updates coordinate, is input to multiple discretization fluid domains and is calculated；

Calculating terminates, and the total time of calculating arrives.

Preferably, the calculating of described discretization fluid domain comprises the following steps：

S201, sets up multiple Nonlinear Oil-Film Forces of Sliding equations；

S202, calls rigid boundary condition's database file, determines the grid section at the lower screw axle journal of current time step Point coordinates；

S203, in computation fluid dynamics software, updates discretization fluid domain using structuring dynamic mesh update method Grid node, obtain up-to-date grid node under multiple Nonlinear Oil-Film Forces of Slidings；

S204, multiple Nonlinear Oil-Film Forces of Slidings are write multiple Nonlinear Film force boundary condition database files；

S205, rigid boundary condition's database file exists, return to step S202；Otherwise, the calculating of discretization fluid domain Terminate.

Preferably, the calculating of described discretization solid domain comprises the following steps：

S301, sets up propeller shaft rotor dynamics equation；

S302, calls multiple Nonlinear Film force boundary condition database files, determines integral domain；

S303, multiple Nonlinear Oil-Film Forces of Slidings are coupled with propeller shaft rotor dynamics equation；

S304, solves propeller shaft rotor dynamics equation using time-domain integration method, obtains at up-to-date screw axle journal Displacement and center；

S305, displacement at described screw axle journal and center are write rigid boundary condition's database file；

S306, multiple Nonlinear Film force boundary condition database files exist, return to step S302；Otherwise, discretization The calculating of solid domain terminates.

Preferably, described structuring dynamic mesh update method comprises the following steps：

S401, calls rigid boundary condition's database file, obtains displacement and center at screw axle journal；

S402, mesh point coordinate identifies；

S403, determines grid node region according to bearing shell line of demarcation equation；

S404, grid node displacement assignment；

S405, determines up-to-date mesh point coordinate.

Preferably, the method for the assignment of mesh point coordinate displacement described in step S404 is：With screw axle journal weight The grid node closing and screw axle journal synchronizing moving assignment, the grid node overlapping with bearing shell keeps assignment constant, screw Grid node between axle journal and bearing shell moves assignment as follows：

${x^{\′}}_i-x_i+\frac{(1-q^{N_i})}{(1-q^N)}\mathrm{\Δ}x,{y^{\′}}_i=y_i+\frac{(1-q^{N_i})}{(1-q^N)}\mathrm{\Δ}y,$

Wherein, (x_i, y_i) coordinate for the mobile front nodal point i of screw axle journal, (x'_i, y'_i) for screw axle journal mobile after The coordinate of node i, N_iRepresent the radial grid number of plies that node i is located, reticulate layer numbering node at bearing shell saves at axle journal The incremented by successively o'clock from 0 to N, N represents total radial grid number of plies, N≤10, and q represents the growth ratio of grid height, 0.96≤q≤ 1.06, and q ≠ 1.

Preferably, the expression formula of described propeller shaft rotor dynamics equation is：

$M\stackrel{\·\·}{s}+C\stackrel{\·}{s}+Ks=B_1{\mathrm{\ω}}^2{\mathrm{Qe}}^{j\mathrm{\ω}t}+B_2{F}_2+B_3{F}_3+B_4{\mathrm{Kr}}_0{e}^{j\mathrm{\ω}t},$

Wherein, M is the mass matrix of propeller shaft rotor-support-foundation system, and s is the displacement of propeller shaft rotor-support-foundation system, and C is spiral shell The damping matrix of rotation oar bearing-rotor system, K is the stiffness matrix of propeller shaft rotor-support-foundation system, and Q is that the quality of propeller shaft is uneven Weigh, F₂For propeller shaft gravity, F₃For Nonlinear Oil-Film Forces of Sliding；Kr₀e^jωtIt is the exciting force being caused by initial bending, r₀Represent just Begin to bend, ω is propeller shaft angular velocity of rotation；B_iFor the location matrix of active force, i≤4.

Preferably, the equation of bearing shell line of demarcation described in step S403 is：

When tail bearing is for elliptic bearing, the general expression of line of demarcation equation is：

$b_1=\frac{b_0(a_1+R)}{a_0-r+R},b_2=\frac{b_0(a_2-R)}{a_0+r-R},$

Wherein：R is the radius of tail bearing, and r is the radius of screw axle journal, (a₀, b₀) sit for screw axle journal center Mark；

When tail bearing is that four oily rachises are held, general expression is：

$b_1=(b_0-r_1)+\frac{(r_1-R_1-b_0)(a_1-a_0-r_1)}{R_1-a_0-r_1},$

$b_2=(b_0+r_1)+\frac{(R_1-r_1-b_0)(a_2-a_0-r_1)}{R_1-a_0-r_1},$

$b_3=(b_0+r_1)+\frac{(R_1-r_1-b_0)(a_3-a_0+r_1)}{-R_1-a_0+r_1},$

$b_4=(b_0-r_1)+\frac{(r_1-R_1-b_0)(a_4-a_0+r_1)}{-R_1-a_0+r_1},$

Wherein：R is the radius of tail bearing, and r is the radius of screw axle journal, (a₀, b₀) sit for screw axle journal center Mark,

Preferably, described time-domain integration method be Newmark method, any one in Runge-Kutta method.

Preferably, described unit interval step-length is according to formula：Unit interval step-length=L × minimum grid length/fluid is special Levy speed to be set, 0.1≤L≤1.

Preferably, the total time of described calculating is according to formula：Total time=calculating total step number × unit time step length is carried out Set.

Being described as follows of the technical solution adopted for the present invention to solve the technical problems：

By fluid domain cell discretization and solid domain cell discretization step, respectively list is carried out to fluid domain and solid domain First discretization, the drawbacks of overcoming traditional mainframe computer software and unify sliding-model control, simplifies subsequent calculations step, after saving Continuous computing resource.

Calculation procedure is coupled by the calculating of discretization fluid domain, the calculating of discretization solid domain and data, in unit In spacer step, the calculating process that Nonlinear Film force boundary condition is discretized solid domain is called, and determines its time-domain integration region, and Using the arbitrary time-domain integration method in Newmark method or Runge-Kutta method calculate output screw axle journal displacement and Center, this screw axle journal displacement and center are written into rigid boundary condition's database file；In same time step Interior, the calculating process that this rigid boundary condition's database file is discretized fluid domain is called, and using structuring dynamic mesh more It is same to obtain the multiple Nonlinear Oil-Film Forces of Slidings under new grid node, the plurality of Nonlinear Oil-Film Forces of Sliding that new method updates grid node When write Nonlinear Film force boundary condition database file, wait the calculating process of discretization solid domain in next time step Call, and so on circulate, until calculate arrives total time, calculating terminates；Achieve discretization fluid domain in same time step With the multiple fluid and structural simulation of discretization solid domain, the course of work of accurate simulation tail bearing and propeller shaft system.

Structuring dynamic mesh update method, accurately judges grid node region using bearing shell line of demarcation equation, passes through Follow the assignment method of screw axle journal movement using mesh point coordinate, the grid node overlapping and spiral shell with screw axle journal Rotation oar axle journal synchronizing moving assignment, the grid node overlapping with bearing shell keeps assignment constant, between screw axle journal and bearing shell Grid node moves assignment as follows：

${x^{\′}}_i=x_i+\frac{(1-q^{N_i})}{(1-q^N)}\mathrm{\Δ}x,{y^{\′}}_i=y_i+\frac{(1-q^{N_i})}{(1-q^N)}\mathrm{\Δ}y,$

Overcome that mesh distortion in traditional dynamic mesh update method is excessive and too low the asking of fluid domain computational accuracy that lead to Topic.

The propeller shaft rotor dynamics equation that discretization solid domain is set up, has taken into full account that the quality of propeller shaft is uneven Weigh, propeller shaft gravity, the various mechanism of action of Nonlinear Oil-Film Forces of Sliding and the exciting force being caused by initial bending, complete many Individual Nonlinear Oil-Film Forces of Sliding and the coupling of propeller shaft rotor dynamics equation, overcome symmetrical Rotor-Bearing System coupling The drawbacks of calculating, the more accurate simulation and announcement propeller shaft and tail bearing coupling mechanism between vibration, lubrication.

Compared with prior art, the present invention is had an advantageous effect in that：

1st, this tail bearing-rotor-support-foundation system multiple fluid and structural simulation method is directed to fluid domain and solid domain carries out unit respectively Discretization, and the calculation procedure of the calculation procedure by discretization fluid domain and discretization solid domain is respectively completed for fluid domain Calculating with solid domain；The feature modeling result that calculation procedure couples discretization fluid domain and solid domain is coupled by data, complete Become the multiple fluid and structural simulation of tail bearing-rotor-support-foundation system it is achieved that tail bearing and the propeller shaft system course of work accurate Simulation；

2nd, using the structuring dynamic mesh update method following screw axle journal moving method based on mesh point coordinate, solution The mesh distortion that existing Dynamic mesh of having determined is applied to the presence of tail bearing numerical simulation is excessive, thus leading to fluid domain to calculate essence Spend low problem；

3rd, this tail bearing-rotor-support-foundation system multiple fluid and structural simulation method take into full account asymmetric between multiple tail bearings Property, the multiple coupling realizing fluid-fluid-solid calculates, and overcomes symmetrical Rotor-Bearing System and couples the drawbacks of calculate, more The accurate simulation and announcement propeller shaft and tail bearing coupling mechanism between vibration, lubrication, is that China's depth develops tool The navigation of deep sea drilling floating platform of autonomous property right and positioning power system is had to provide important technical support.

Brief description

Fig. 1 tail bearing-rotor-support-foundation system multiple fluid and structural simulation method and step FB(flow block).

The calculation procedure FB(flow block) of Fig. 2 discretization fluid domain.

The calculation procedure FB(flow block) of Fig. 3 discretization solid domain.

Fig. 4 structuring dynamic mesh update method steps flow chart block diagram.

Specific embodiment

The multiple fluid and structural simulation method of 1～4 pair of tail bearing-rotor-support-foundation system of the present invention is done furtherly below in conjunction with the accompanying drawings Bright.

Fig. 1 be tail bearing-rotor-support-foundation system multiple fluid and structural simulation method and step FB(flow block), including multiple tail bearings, One propeller shaft, further comprising the steps of：

Step S101, unit interval step-length installation warrants formula：Unit interval step-length=L × minimum grid length/fluid Characteristic velocity is set, wherein, 0.1≤L≤1；The total time installation warrants formula calculating：Total time=calculating total step number × Unit time step length is set, and calculates step number and presets；

Step S102, fluid domain cell discretization；That is, the cell discretization of the area of space that multiple tail bearings occupy；Adopt Carry out fluid domain with Gambit software discrete, grid cell size is set, using Cooper gridding method, by tail bearing oil film Gap is divided into structured grid；

Step S103, solid domain cell discretization；That is, the cell discretization of propeller shaft rotor dynamics equation；Using The cubic polynomial overlapping each other, as Rayleigh function, propeller shaft is processed as continuous beam, whole axle not only displacement and speed Degree is continuous, and moment of flexure and shearing also keep continuous, and the corner of rotating shaft is then represented by the derivative of rotating shaft displacement, is so examining On the premise of considering the impact of system gyroscope moment, its number of degrees of freedom, decreases half than conventional Finite Element Discretization Technique, screw The equation of motion of axle is linear, and other non-linear factors are by acting on the description of the generalized force on propeller shaft, and adopt Nonlinear fault power is coupled in system differential equation for Modal Synthesis Technique and position function；

Step S104, the calculating of discretization fluid domain；Discretization fluid domain is updated using structuring dynamic mesh update method Grid node, and obtain fluid matasomatism in the borderline Nonlinear Oil-Film Forces of Sliding of propeller shaft；

Step S105, the calculating of discretization solid domain；Propeller shaft rotor dynamics equation is solved using time-domain integration method, Obtain displacement and center at screw axle journal；Time-domain integration method can adopt Newmark method or Runge-Kutta method；

Step S106, data coupling calculates；In unit interval step-length, using multiple described Nonlinear Oil-Film Forces of Slidings as discretization The boundary condition of solid domain, is input to discretization solid domain and is calculated；In same time step, by displacement at screw axle journal And center, as the grid renewal coordinate of discretization fluid domain, it is input to multiple discretization fluid domains and is calculated；

Step S107, the total time of calculating arrives, and calculating terminates, and otherwise continues discretization solid domain or discretization fluid domain Calculate.

Fig. 2 is the calculation procedure FB(flow block) of discretization fluid domain, and the calculating of described discretization fluid domain includes following step Suddenly：

Step S201, sets up multiple Nonlinear Oil-Film Forces of Sliding equations, and equation expression formula is：

$F_x=R{\∫}_0^L{\∫}_0^{2\mathrm{\π}}psin\mathrm{\θ}d\mathrm{\θ}dz,$

$F_y=R{\∫}_0^L{\∫}_0^{2\mathrm{\π}}pcos\mathrm{\θ}d\mathrm{\θ}dz,$

Wherein：R is tail bearing radius, and L is tail bearing length, and θ is tail bearing angle of circumference, and p is oil film pressure；By calculating Hydrodynamics software, after the parameter such as setting unit time step, calculating total step number, boundary condition, propeller shaft rotating speed, calculating can Obtain multiple Nonlinear Oil-Film Forces of Slidings；

Step S202, calls rigid boundary condition's database file, determines grid at the lower screw axle journal of current time step Node coordinate, rigid boundary condition's database file extends entitled .dat；

Step S203, updates the grid node of discretization fluid domain using structuring dynamic mesh update method, obtains up-to-date Multiple Nonlinear Oil-Film Forces of Slidings under grid node；

Step S204, multiple Nonlinear Oil-Film Forces of Slidings are write multiple Nonlinear Film force boundary condition database files；Many Individual Nonlinear Film force boundary condition database file extends entitled .dat；

Step S205, rigid boundary condition's database file exists, return to step S202；Otherwise, discretization fluid domain Calculating terminates.

Nonlinear Film force boundary condition database file and rigid boundary condition's database file, are being calculated accordingly It is automatically deleted after the invocation of procedure.

Fig. 3 is the calculation procedure FB(flow block) of discretization solid domain, and the calculating of described discretization solid domain includes following step Suddenly：

Step S301, sets up propeller shaft rotor dynamics equation：

$M\stackrel{\·\·}{s}+C\stackrel{\·}{s}+Ks=B_1{\mathrm{\ω}}^2{\mathrm{Qe}}^{j\mathrm{\ω}t}+B_2{F}_2+B_3{F}_3+B_4{\mathrm{Kr}}_0{e}^{j\mathrm{\ω}t},$

Wherein, M is the mass matrix of propeller shaft rotor-support-foundation system, and s is the displacement of propeller shaft rotor-support-foundation system, and C is spiral shell The damping matrix of rotation oar bearing-rotor system, K is the stiffness matrix of propeller shaft rotor-support-foundation system, and Q is that the quality of propeller shaft is uneven Weigh, F₂For propeller shaft gravity, F₃For Nonlinear Oil-Film Forces of Sliding；Kr₀e^jωtIt is the exciting force being caused by initial bending, r₀Represent just Begin to bend, ω is propeller shaft angular velocity of rotation；B_iFor the location matrix of active force, i≤4；

Step S302, calls multiple Nonlinear Film force boundary condition database files, determines time-domain integration region；

Step S303, multiple Nonlinear Oil-Film Forces of Slidings are coupled with propeller shaft rotor dynamics equation, and its coupled wave equation is：

$F={\stackrel{\‾}{X}}^T\underset{i=1}{\overset{n}{\Σ}}{\left[\begin{array}{cc}{J}_T& J_R\end{array}\right]}_{z=z_{fi}}={\left[\begin{array}{cc}{f}_i^e& l_i^e\end{array}\right]}^T$

Wherein：F is generalized force, herein refers to Nonlinear Oil-Film Forces of Sliding, this equation can be used for other non-linear exciting-vibration force Coupling,For modal transfer matrix, Represent screw respectively 1 rank of axle rotor dynamics equation, 2 ranks ..., n rank characteristic vector, J_TAnd J_RIt is respectively translation and the rotation of Nonlinear Oil-Film Forces of Sliding Location matrix,W is the axial location function of propeller shaft, f_i ^eAnd l_i ^eIt is respectively and act on The concentrated force of i-th Nonlinear Oil-Film Forces of Sliding on propeller shaft and concentrated moment, active position isZ direction is parallel In propeller shaft axially direction.

Step S304, solves propeller shaft rotor dynamics equation using time-domain integration method, obtains up-to-date propeller shaft Displacement and center at neck；

Step S305, displacement at described screw axle journal and center are write rigid boundary condition's database file；

Step S306, multiple Nonlinear Film force boundary condition database files exist, return to step S302；Otherwise, from The calculating of dispersion solid domain terminates.

Nonlinear Film force boundary condition database file and rigid boundary condition's database file, are being calculated accordingly It is automatically deleted after the invocation of procedure.

Fig. 4 be structuring dynamic mesh update method steps flow chart block diagram, described structuring dynamic mesh update method include with Lower step：

Step S401, calls rigid boundary condition's database file, obtains displacement and center at screw axle journal；

Step S402, identifies mesh point coordinate according to displacement at screw axle journal and center；

Step S403, determines grid node region according to bearing shell line of demarcation equation；The bearing shell line of demarcation of different structure bearing Equation is also different, and when tail bearing is for elliptic bearing, the general expression of line of demarcation equation is：

$b_1=\frac{b_0(a_1-R)}{a_0+r-R},b_2=\frac{b_0(a_2+R)}{a_0-r+R},$

Wherein：R is the radius of tail bearing, and r is the radius of screw axle journal, (a₀, b₀) it is journal centre's position coordinates；

When tail bearing is that four oily rachises are held, general expression is：

$b_1=(b_0-r_1)+\frac{(r_1-R_1-b_0)(a_1-a_0-r_1)}{R_1-a_0-r_1},$

$b_2=(b_0+r_1)+\frac{(R_1-r_1-b_0)(a_2-a_0-r_1)}{R_1-a_0-r_1},$

$b_3=(b_0+r_1)+\frac{(R_1-r_1-b_0)(a_3-a_0+r_1)}{-R_1-a_0+r_1},$

$b_4=(b_0-r_1)+\frac{(r_1-R_1-b_0)(a_4-a_0+r_1)}{-R_1-a_0+r_1},$

Wherein：R is the radius of tail bearing, and r is the radius of screw axle journal, (a₀, b₀) it is journal centre's position coordinates,

Step S404, grid node displacement assignment；The grid node overlapping with screw axle journal and screw axle journal Synchronizing moving assignment, the grid node overlapping with bearing shell keeps assignment constant, the grid node between screw axle journal and bearing shell Move assignment as follows：

${x^{\′}}_i-x_i+\frac{(1-q^{N_i})}{(1-q^N)}\mathrm{\Δ}x,{y^{\′}}_i=y_i+\frac{(1-q^{N_i})}{(1-q^N)}\mathrm{\Δ}y,$

Wherein, (x_i, y_i) coordinate for the mobile front nodal point i of axle journal, (x'_i, y'_i) coordinate for the mobile posterior nodal point i of axle journal, N_i Represent the radial grid number of plies that node i is located, reticulate layer numbering node node at axle journal at bearing shell is passed to N successively from 0 Increase, N represents total radial grid number of plies, N is positive integer, N≤10, q represents the growth ratio of grid height, 0.96≤q≤1.06, and q≠1；

Step S405, determines and updates mesh point coordinate, and that is, up-to-date mesh point coordinate determines.

The initial fluid domain grid model of embodiment 1～2 adopts structured grid to divide, and radial grid gap length is consistent, Grid node in identical tile fragment region has the identical center of circle, and propeller shaft system is processed as continuous beam, has multiple thin circles Disk rigid body forms, and propeller shaft is overall to be to support by two tail bearings, and propeller shaft quality is divided in the width range of itself Cloth quality treatment, the corner vibration of propeller shaft is represented by the displacement derivatives of propeller shaft.

Embodiment 1：Two four oily leaf tail Rotor-Bearing System multiple fluid and structural simulation processes, are that the present invention is most preferably real Apply example.

1.1, setting unit time step Δ t₁, the total time T of calculating₁；

1.2, using computation fluid dynamics software, numerical computations are carried out to two four oily leaf tail bearings simultaneously, obtain two Nonlinear Oil-Film Forces of Sliding (the Fx of individual four oily leaf tail bearings₁, Fy₁)、(Fx₂, Fy₂)；

1.3, by Δ t₁, current calculate time T_d1、(Fx₁, Fy₁)、(Fx₂, Fy₂) non-as the calculating of discretization solid domain Linear oil-film force boundary condition writes two four oily leaf tail bearing boundary condition database files；

1.4, discretization solid domain calculates and sets up propeller shaft rotor dynamics equation：

$M\stackrel{\·\·}{s}+C\stackrel{\·}{s}+Ks=B_1{\mathrm{\ω}}^2{\mathrm{Qe}}^{j\mathrm{\ω}t}+B_2{F}_2+B_3{F}_3+B_4{\mathrm{Kr}}_0{e}^{j\mathrm{\ω}t},$

Wherein, M is the mass matrix of propeller shaft rotor-support-foundation system, and s is the displacement of propeller shaft rotor-support-foundation system, and C is spiral shell The damping matrix of rotation oar bearing-rotor system, K is the stiffness matrix of propeller shaft rotor-support-foundation system, and Q is that the quality of propeller shaft is uneven Weigh, F₂For propeller shaft gravity, F₃For Nonlinear Oil-Film Forces of Sliding, Kr₀e^jωtFor propeller shaft in exciting, touch and rub, misalign situation Under, the exciting force that caused by initial bending, r₀Represent initial bending, ω is propeller shaft angular velocity of rotation；B_iFor above-mentioned active force Location matrix, i≤4, i rounds numerical value；

1.5, discretization solid domain calculates and calls the oily leaf tail bearing boundary condition database file of above-mentioned two four, determines Newmark method integral domain；

1.6, by formula：

$F-{\stackrel{\‾}{X}}^T\underset{i=1}{\overset{n}{\Σ}}{{\left[\begin{array}{cc}{J}_T& J_R\end{array}\right]}^T}_{z=z_{Fi}}{\left[\begin{array}{cc}{f}_i^e& l_i^e\end{array}\right]}^T$

By (Fx₁, Fy₁)、(Fx₂, Fy₂) couple with propeller shaft rotor dynamics equation；Wherein, X^TFor modal transformation square Battle array,

$\stackrel{\‾}{X}=\left(\begin{array}{cc}\stackrel{\‾}{X_w}& 0\\ 0& \stackrel{\‾}{X_w}\end{array}\right),$

Represent respectively propeller shaft rotor dynamics equation 1 rank, 2 Rank ..., n rank characteristic vector, J_TAnd J_RIt is respectively translation and the turned position matrix of Nonlinear Oil-Film Forces of Sliding,

$J_T=\left[\begin{array}{cc}{w}^T& 0\\ 0& w^T\\ 0& 0\end{array}\right],J_R=\left[\begin{array}{cc}0& -w^{,T}\\ w^{,T}& 0\\ 0& 0\end{array}\right],$

W is the axial location function of propeller shaft, f_i ^eAnd l_i ^eI-th respectively acted on propeller shaft non-linear The concentrated force of oil-film force and concentrated moment；

1.7, solve above-mentioned propeller shaft rotor dynamics equation using Newmark integration method；

1.8, by calculated screw axle journal displacement (the Δ x at two four oily leaf tail bearings respectively₁、Δy₁)、 (Δx₂、Δy₂) and center (x₁、y₁)、(x₂、y₂) it is stored in rigid boundary condition's database file；

1.9, the total time T of calculating₁Do not arrive and Nonlinear Film force boundary condition database file exists, then return to step 1.5；Otherwise, if the total time T calculating₁Do not arrive then entrance step 1.10, the total time T of calculating₁Terminate to then calculating；

1.10, using structuring dynamic mesh update method, call rigid boundary condition's database file, read current spiral Displacement (Δ x at two four oily leaf tail bearings for the oar axle journal₁、Δy₁)、(Δx₂、Δy₂) and center (x₁、y₁)、(x₂、 y₂)；Identify that current time walks Δ t by calculating fluid software CFD₁Interior mesh point coordinate is (m₁, n₁), two four oily leaves The region occupied by single four oily leaf tail bearings of tail bearing be divide into four parts by four tile fragment lines of demarcation, and line of demarcation with The movement of screw axle journal and change, four marginal equations are respectively：

$b_1=(y_1-r_1)+\frac{(r_1-R_1-y_1)(a_1-x_1-r_1)}{R_1-x_1-r_1}$

$b_2=(y_1+r_1)+\frac{(R_1-r_1-y_1)(a_2-x_1-r_1)}{R_1-x_1-r_1}$

$b_3=(y_1+r_1)+\frac{(R_1-r_1-y_1)(a_3-x_1+r_1)}{-R_1-x_1+r_1}$

$b_4=(y_1-r_1)+\frac{(r_1-R_1-y_1)(a_4-x_1+r_1)}{-R_1-x_1+r_1}$

The bearing shell line of demarcation equation of another four oily leaf tail bearing is

$b_5=(y_2-r_1)+\frac{(r_1-R_1-y_2)(a_5-x_2-r_1)}{R_1{x}_2-r_1}$

$b_6=(y_2+r_1)+\frac{(R_1-r_1-y_2)(a_6-x_2-r_1)}{R_1-x_2-r_1}$

$b_7=(y_2+r_1)+\frac{(R_1-r_1-y_2)(a_7-x_2+r_1)}{-R_1-x_2+r_1}$

$b_8=(y_2-r_1)+\frac{(r_1-R_1-y_2)(a_8-x_2+r_1)}{-R_1-x_2+r_1};$

(m is judged according to above-mentioned bearing shell line of demarcation equation₁, n₁) the flow field domain that is located, that is,：

Work as n₁≤b₁And n₁＜ b₄When, mesh point coordinate (m₁, n₁) it is in a₁b₁And a₄b₄The fluid domain that line of demarcation determines Interior；

Work as n₁≤b₂And n₁＞ b₁When, mesh point coordinate (m₁, n₁) it is in a₁b₁And a₂b₂The fluid domain that line of demarcation determines Interior；

Work as n₁＞ b₂And n₁≥b₃When, mesh point coordinate (m₁, n₁) it is in a₂b₂And a₃b₃The fluid domain that line of demarcation determines Interior；

Work as n₁＜ b₃And n₁≥b₄When, mesh point coordinate (m₁, n₁) it is in a₃b₃And a₄b₄The fluid domain that line of demarcation determines Interior；

Work as n₁≤b₅And n₁＜ b₈When, mesh point coordinate (m₁, n₁) it is in a₅b₅And a₈b₈The fluid domain that line of demarcation determines Interior；

Work as n₁≤b₆And n₁＞ b₅When, mesh point coordinate (m₁, n₁) it is in a₅b₅And a₆b₆The fluid domain that line of demarcation determines Interior；

Work as n₁＞ b₆And n₁≥b₇When, mesh point coordinate (m₁, n₁) it is in a₆b₆And a₇b₇The fluid domain that line of demarcation determines Interior；

Work as n₁＜ b₇And n₁≥b₈When, mesh point coordinate (m₁, n₁) it is in a₇b₇And a₈b₈The fluid domain that line of demarcation determines Interior；

1.11 for the assignment of the grid node displacement in the domain of each flow field, the grid node overlapping with screw axle journal With screw axle journal synchronizing moving assignment, the grid node that overlaps with bearing shell keeps assignment constant, screw axle journal and bearing shell it Between grid node move assignment as follows：

$x_{i^{,}}=x_i+\frac{(1-q^{N_i})}{(1-q^N)}\mathrm{\Δ}x,y_{i^{,}}=y_i+\frac{(1-q^{N_i})}{(1-q^N)}\mathrm{\Δ}y,$

I.e. for time step Δ t₁Interior mesh point coordinate (m₁, n₁), when it is overlapped with screw axle journal, now net Lattice node coordinate is (m₁+ Δ x, n₁+Δy)；When it is overlapped with bearing shell, now mesh point coordinate is (m₁, n₁)；When it is in spiral shell (N when between rotation oar axle journal and bearing shell_i=2, N=7, q=0.96), now mesh point coordinate is

${m^{\′}}_1=m_1+\frac{(1-{0.96}^2)}{(1-{0.96}^7)}\mathrm{\Δ}x,{n^{\′}}_1=n_1+\frac{(1-{0.96}^2)}{(1-{0.96}^7)}\mathrm{\Δ}y,$

Wherein, as mesh point coordinate (m₁, n₁) determine in a₁b₁～a₄b₄During the flow field domain that bearing shell line of demarcation is located, Δ x =Δ x₁, Δ y=Δ y₁；Mesh point coordinate (m₁, n₁) determine in a₅b₅～a₈b₈Δ x during the flow field domain that bearing shell line of demarcation is located =Δ x₂, Δ y=Δ y₂；

1.12, grid node updates and completes, and obtains up-to-date grid node (m'₁, n'₁) under two four oily leaf tail bearings Nonlinear Oil-Film Forces of Sliding (Fx₃, Fy₃)、(Fx₄, Fy₄)；

1.13, the total time T of calculating₁Do not arrive and rigid boundary condition's database file exists, return to step 1.4；Otherwise, If the total time T calculating₁Do not arrive then entrance step 1.3, the total time T of calculating₁Terminate to then calculating.

Embodiment 2：The multiple fluid and structural simulation process of three oval tail bearing-rotor-support-foundation systems.

2.1, setting unit time step Δ t₂, the total time T of calculating₂；

2.2, using computation fluid dynamics software, numerical computations are carried out to three oval tail bearings simultaneously, obtain three Nonlinear Oil-Film Forces of Sliding (the Fx of oval tail bearing₅, Fy₅)、(Fx₆, Fy₆)、(Fx₇, Fy₇)；

2.3, by Δ t₂, current calculate time T_d2、(Fx₅, Fy₅)、(Fx₆, Fy₆)、(Fx₇, Fy₇) as discretization solid domain The Nonlinear Film force boundary condition calculating writes three oval tail bearing boundary condition database files；

2.4, discretization solid domain calculates and sets up propeller shaft rotor dynamics equation：

$M\stackrel{\·\·}{s}+C\stackrel{\·}{s}+Ks=B_1{\mathrm{\ω}}^2{\mathrm{Qe}}^{j\mathrm{\ω}t}+B_2{F}_2+B_3{F}_3+B_4{\mathrm{Kr}}_0{e}^{j\mathrm{\ω}t};$

2.5, discretization solid domain calculates and calls above three ellipse tail bearing boundary condition database file, determines Runge-Kutta method integral domain；

2.6, formula is coupled by (Fx by Nonlinear Oil-Film Forces of Sliding of the present invention with propeller shaft rotor dynamics equation₅, Fy₅)、 (Fx₆, Fy₆)、(Fx₇, Fy₇) couple with propeller shaft rotor dynamics equation；

2.7, solve propeller shaft rotor dynamics equation using Runge-Kutta integration method；

2.8, by calculated screw axle journal displacement (the Δ x at three oval tail bearings respectively₃、Δy₃)、(Δ x₄、Δy₄)、(Δx₅、Δy₅) and center (x₃、y₃)、(x₄、y₄)、(x₅、y₅) it is stored in rigid boundary condition's database file；

2.9, the total time T of calculating₂Do not arrive and Nonlinear Film force boundary condition database file exists, then return to step 2.5；Otherwise, if the total time T calculating₂Do not arrive then entrance step 2.10, the total time T of calculating₂Terminate to then calculating；

2.10, using structuring dynamic mesh update method, call rigid boundary condition's database file, read current (Δx₃、Δy₃)、(Δx₄、Δy₄)、(Δx₅、Δy₅) and (x₃、y₃)、(x₄、y₄)、(x₅、y₅), by calculating fluid software CFD Identification current time step Δ t₂Interior mesh point coordinate is (m₂, n₂), shared by the single ellipse tail bearing of three oval tail bearings According to region be divide into two parts by two tile fragment lines of demarcation, and line of demarcation changes, two with the movement of screw axle journal The marginal equation of bar is respectively：

$b_2=\frac{y_3(a_2+R)}{x_3-r+R},b_1=\frac{y_3(a_1-R)}{x_3+r-R};$

The bearing shell line of demarcation equation of other two oval tail bearings is：

$b_3=\frac{y_4(a_3-R)}{x_4+r-R},b_4=\frac{y_4(a_4+R)}{x_4-r+R},$

$b_5=\frac{y_5(a_5-R)}{x_5+r-R},b_6=\frac{y_5(a_6+R)}{x_5-r+R},$

(m is judged according to above-mentioned bearing shell line of demarcation equation₂, n₂) the flow field domain that is located, that is,：

Work as m₂>=0 and n₂≤b₁When or m₂＜ 0 and n₂≤b₂When, mesh point coordinate (m₂, n₂) it is in a₁b₁Line of demarcation is along suitable Clockwise is to a₂b₂In the fluid domain that line of demarcation is located；

Work as m₂>=0 and n₂＞ b₁When or m₂＜ 0 and n₂＞ b₂When, mesh point coordinate (m₂, n₂) it is in a₁b₁Line of demarcation is along inverse Clockwise is to a₂b₂In the fluid domain that line of demarcation is located；

Work as m₂>=0 and n₂≤b₃When or m₂＜ 0 and n₂≤b₄When, mesh point coordinate (m₂, n₂) it is in a₃b₃Line of demarcation is along suitable Clockwise is to a₄b₄In the fluid domain that line of demarcation is located；

Work as m₂>=0 and n₂＞ b₃When or m₂＜ 0 and n₂＞ b₄When, mesh point coordinate (m₂, n₂) it is in a₃b₃Line of demarcation is along inverse Clockwise is to a₄b₄In the fluid domain that line of demarcation is located；

Work as m₂>=0 and n₂≤b₅When or m₂＜ 0 and n₂≤b₆When, mesh point coordinate (m₂, n₂) it is in a₅b₅Line of demarcation is along suitable Clockwise is to a₆b₆In the fluid domain that line of demarcation is located；

Work as m₂>=0 and n₂＞ b₅When or m₂＜ 0 and n₂＞ b₆When, mesh point coordinate (m₂, n₂) it is in a₅b₅Line of demarcation is along inverse Clockwise is to a₆b₆In the fluid domain that line of demarcation is located；

2.11, grid node displacement assignment moves assignment method also in compliance with grid node of the present invention, and root According to screw axle journal displacement (the Δ x at three oval tail bearings respectively₃、Δy₃)、(Δx₄、Δy₄)、(Δx₅、Δy₅) assigning Value simultaneously accurately judges current mesh node region；I.e. for time step Δ t₂Interior mesh point coordinate (m₂, n₂), when it When overlapping with screw axle journal, now mesh point coordinate is (m₂+ Δ x, n₂+Δy)；When it is overlapped with bearing shell, now grid section Point coordinates is (m₂, n₂)；(the N when it is between screw axle journal and bearing shell_i=9, N=10, q=1.01), now grid node Coordinate is

${m^{\′}}_2=m_2+\frac{(1-{1.01}^9)}{(1-{1.01}^{10})}\mathrm{\Δ}x,{n^{\′}}_2=n_2+\frac{(1-{1.01}^9)}{(1-{1.01}^{10})}\mathrm{\Δ}y,$

Wherein, as mesh point coordinate (m₂, n₂) determine in a₁b₁、a₂b₂During the flow field domain that bearing shell line of demarcation is located, Δ x= Δx₃, Δ y=Δ y₃；Mesh point coordinate (m₂, n₂) determine in a₃b₃、a₄b₄During the flow field domain that bearing shell line of demarcation is located, Δ x= Δx₄, Δ y=Δ y₄；Mesh point coordinate (m₂, n₂) determine in a₅b₅、a₆b₆During the flow field domain that bearing shell line of demarcation is located, Δ x= Δx₅, Δ y=Δ y₅；

2.12, grid node updates and completes, and obtains the Nonlinear Film of three oval tail bearings under up-to-date grid node Power (Fx₈, Fy₈)、(Fx₉, Fy₉)、(Fx₁₀, Fy₁₀)；

2.13, the total time T of calculating₂Do not arrive and rigid boundary condition's database file exists, return to step 2.4；Otherwise, If the total time T calculating₂Do not arrive then entrance step 2.3, the total time T of calculating₂Terminate to then calculating.

The above, be only presently preferred embodiments of the present invention, is not the restriction that the present invention is made with other forms, appoints What those skilled in the art possibly also with the disclosure above technology contents changed or be modified as equivalent variations etc. Effect embodiment.But every without departing from technical solution of the present invention content, according to the present invention technical spirit to above example institute Any simple modification, equivalent variations and the remodeling made, still falls within the protection domain of technical solution of the present invention.

Claims (10)

1. a kind of multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system, including multiple tail bearings, a propeller shaft, its It is characterised by：Further comprising the steps of：

The setting of unit interval step-length and the total time setting calculating；

Fluid domain cell discretization, the cell discretization of the area of space that multiple tail bearings occupy；

Solid domain cell discretization, the cell discretization of propeller shaft rotor dynamics equation；

The calculating of discretization fluid domain, updates discretization fluid domain grid node using structuring dynamic mesh update method, and obtains Obtain fluid matasomatism in the borderline Nonlinear Oil-Film Forces of Sliding of propeller shaft；

The calculating of discretization solid domain, solves propeller shaft rotor dynamics equation using time-domain integration method, obtains propeller shaft Displacement and center at neck；

Data coupling calculate, in unit interval step-length, using multiple described Nonlinear Oil-Film Forces of Slidings as discretization solid domain border Condition, is input to discretization solid domain and is calculated；In same time step, by displacement and center at screw axle journal, Grid as discretization fluid domain updates coordinate, is input to multiple discretization fluid domains and is calculated；

Calculating terminates, and the total time of calculating arrives.

2. the multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system according to claim 1 it is characterised in that：Described The calculating of discretization fluid domain comprises the following steps：

S201, sets up multiple Nonlinear Oil-Film Forces of Sliding equations；

S202, calls rigid boundary condition's database file, determines that the grid node at the lower screw axle journal of current time step is sat Mark；

S203, in computation fluid dynamics software, updates the net of discretization fluid domain using structuring dynamic mesh update method Lattice node, obtains the multiple Nonlinear Oil-Film Forces of Slidings under up-to-date grid node；

S204, multiple Nonlinear Oil-Film Forces of Slidings are write multiple Nonlinear Film force boundary condition database files；

S205, rigid boundary condition's database file exists, return to step S202；Otherwise, the calculating of discretization fluid domain terminates.

3. the multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system according to claim 1 it is characterised in that：Described The calculating of discretization solid domain comprises the following steps：

S301, sets up propeller shaft rotor dynamics equation；

S302, calls multiple Nonlinear Film force boundary condition database files, determines integral domain；

S303, multiple Nonlinear Oil-Film Forces of Slidings are coupled with propeller shaft rotor dynamics equation；

S304, solves propeller shaft rotor dynamics equation using time-domain integration method, obtains displacement at up-to-date screw axle journal And center；

S305, displacement at described screw axle journal and center are write rigid boundary condition's database file；

S306, multiple Nonlinear Film force boundary condition database files exist, return to step S302；Otherwise, discretization solid The calculating in domain terminates.

4. the multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system according to claim 2 it is characterised in that：Described Structuring dynamic mesh update method comprises the following steps：

S401, calls rigid boundary condition's database file, obtains displacement and center at screw axle journal；

S402, mesh point coordinate identifies；

S403, determines grid node region according to bearing shell line of demarcation equation；

S404, grid node displacement assignment；

S405, determines up-to-date mesh point coordinate.

5. the multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system according to claim 4 it is characterised in that：Step The method of the assignment of mesh point coordinate displacement described in S404 is：The grid node overlapping with screw axle journal and screw Axle journal synchronizing moving assignment, the grid node overlapping with bearing shell keeps assignment constant, the grid between screw axle journal and bearing shell Node moves assignment as follows：

${x^{\′}}_i=x_i+\frac{(1-q^{N_i})}{(1-q^N)}\mathrm{\Δ}x,{y^{\′}}_i=y_i+\frac{(1-q^{N_i})}{(1-q^N)}\mathrm{\Δ}y,$

Wherein, (x_i, y_i) coordinate for the mobile front nodal point i of screw axle journal, (x'_i, y'_i) move posterior nodal point i for screw axle journal Coordinate, N_iRepresent the radial grid number of plies that node i is located, reticulate layer numbering at bearing shell node at axle journal node from 0 To N incremented by successively, N represents total radial grid number of plies, N≤10, and q represents the growth ratio of grid height, 0.96≤q≤1.06, and q ≠1.

6. the multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system according to claim 3 it is characterised in that：Described The expression formula of propeller shaft rotor dynamics equation is：

$M\stackrel{\·\·}{s}+C\stackrel{\·}{s}+Ks=B_1{\mathrm{\ω}}^2{\mathrm{Qe}}^{j\mathrm{\ω}t}+B_2{F}_2+B_3{F}_3+B_4{\mathrm{Kr}}_0{e}^{j\mathrm{\ω}t},$

Wherein, M is the mass matrix of propeller shaft rotor-support-foundation system, and s is the displacement of propeller shaft rotor-support-foundation system, and C is screw The damping matrix of bearing-rotor system, K is the stiffness matrix of propeller shaft rotor-support-foundation system, and Q is the mass unbalance amount of propeller shaft, F₂For propeller shaft gravity, F₃For Nonlinear Oil-Film Forces of Sliding；Kr₀e^jωtIt is the exciting force being caused by initial bending, r₀Represent initially curved Song, ω is propeller shaft angular velocity of rotation；B_iFor the location matrix of active force, i≤4.

7. the multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system according to claim 4 it is characterised in that：Step The equation of bearing shell line of demarcation described in S403 is：

When tail bearing is for elliptic bearing, the general expression of line of demarcation equation is：

$b_1=\frac{b_0(a_1-R)}{a_0+r-R},b_2=\frac{b_0(a_2+R)}{a_0-r+R},$

Wherein：R is the radius of tail bearing, and r is the radius of screw axle journal, (a₀, b₀) it is screw axle journal center position coordinates；

When tail bearing is that four oily rachises are held, general expression is：

$b_1=(b_0-r_1)+\frac{(r_1-R_1-b_0)(a_1-a_0-r_1)}{R_1-a_0-r_1},$

$b_2=(b_0+r_1)+\frac{(R_1-r_1-b_0)(a_2-a_0-r_1)}{R_1-a_0-r_1},$

$b_3=(b_0+r_1)+\frac{(R_1-r_1-b_0)(a_3-a_0+r_1)}{-R_1-a_0+r_1},$

$b_4=(b_0-r_1)+\frac{(r_1-R_1-b_0)(a_4-a_0+r_1)}{-R_1-a_0+r_1},$

Wherein：R is the radius of tail bearing, and r is the radius of screw axle journal, (a₀, b₀) it is screw axle journal center position coordinates,

8. the multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system according to claim 1 it is characterised in that：Described Time-domain integration method is Newmark method, any one in Runge-Kutta method.

9. the multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system according to claim 1 it is characterised in that：Described Unit interval step-length is according to formula：Unit interval step-length=L × minimum grid length/characteristic of fluid speed is set, 0.1≤ L≤1.

10. the multiple fluid and structural simulation method of tail bearing-rotor-support-foundation system according to claim 1 it is characterised in that：Described The total time calculating is according to formula：Total time=calculating total step number × unit time step length is set.