scholarly journals Speed Governing Performance of the Permanent Magnetic Coupler under Centrifugal Load

2019 ◽  
Vol 55 (14) ◽  
pp. 225
Author(s):  
WU Ming ◽  
MA Yushun ◽  
KUANG Jun ◽  
HUANG Xiaobing
Keyword(s):  
Centrifugal Load

Pre-Deformation Method for Manufactured Compressor Blade Based on Load Incremental Approach

2020 ◽  
Vol 37 (3) ◽  
pp. 259-265
Author(s):  
Kang Da ◽  
Wang Yongliang ◽  
Zhong Jingjun ◽  
Liu Zihao
Keyword(s):  
Compressor Blade ◽  
Aerodynamic Load ◽  
Deformation Method ◽  
Transonic Compressor ◽  
Incremental Approach ◽  
Compressor Rotor ◽  
Centrifugal Load ◽  
Blade Shape ◽  
Stationary Shape ◽  
Deformation Procedure

AbstractThe blade deformation caused by aerodynamic and centrifugal loads during operating makes blade configurations different from their stationary shape. Based on the load incremental approach, a novel pre-deformation method for cold blade shape is provided in order to compensate blade deformation under running. Effect of nonlinear blade stiffness is considered by updating stiffness matrix in response to the variation of blade configuration when calculating deformations. The pre-deformation procedure is iterated till a converged cold blade shape is obtained. The proposed pre-deformation method is applied to a transonic compressor rotor. Effect of load conditions on blade pre-deformation is also analyzed. The results show that the pre-deformation method is easy to implement with fast convergence speed. Neither the aerodynamic load nor centrifugal load can be neglected in blade pre-deformation.

Analysis of Coupled Bending-Axial Vibration of a Rotor

2013 ◽  
Vol 662 ◽  
pp. 608-611 ◽  
Author(s):  
Jian Feng Ye ◽  
Chun Long Zheng ◽  
Xue Shi Yao
Keyword(s):  
Axial Force ◽  
Vibration Frequency ◽  
Torsional Vibration ◽  
Stiffness Matrix ◽  
Tensile Force ◽  
Vibration Frequencies ◽  
Axial Vibration ◽  
Bending Vibration ◽  
Centrifugal Load ◽  
Rotor Model

Aiming at a rotor model, the coupled bending-axial vibration is being analyzed.Calculation results show that the prestress relative to rotational centrifugal load may influence bending vibration frequencies of a rotor.The bending vibration frequencies will increase when the prestress increases.The axial vibration frequency has not an influence because the direction of the spinning prestress is perpendicular to axis.When a rotor is applies axial force, a compressional force will tend to increase the axial vibration frequencies while a tensile force will decrease the axial vibration frequencies.The effects of the prestress(centrifugal load )of the spinning rotor and the axial prestress can be accounted by an adjustment of the stiffness matrix for analysis.By use of the stiffness matrix,the changed axial and bending vibration frequencies can be explained.The coupled bending-axial vibration may take place when the bending vibration frequencies have increased in the state of the changed prestress.In the end, the coupled bending-axial vibration frequency can be calculated.On the basis of prestress, the coupled lateral-torsional vibration and the coupled torsional-axial vibration frequency can be analysed,similarly.

The Use of Experimental Design for the Shrink-Fit Assembly of Multi-Ring Flywheel

2014 ◽  
Author(s):  
Yujin Wang ◽  
DeZhong Wang ◽  
Junlian Yin ◽  
Yaoyu Hu
Keyword(s):  
Wall Thickness ◽  
Structural Integrity ◽  
Tungsten Alloy ◽  
Surface Model ◽  
Latin Hypercube Design ◽  
Coolant Pump ◽  
Centrifugal Load ◽  
Key Variables ◽  
Integrity Analysis ◽  
Shrink Fit

The flywheel of latest coolant pump provides high inertia to ensure a slow decrease in coolant flow to prevent fuel damage after the loss of power. Flywheel comprises a hub, twelve tungsten alloy blocks and a retainer ring shrink-fit assembled on the outer surface of blocks. In the structural integrity analysis, the shrinkage load due to shrink-fit and the centrifugal load due to rotation are considered, so the wall thickness of retainer ring and the magnitude of shrink-fit are key variables. In particular, these variables will change the flywheel running state. This paper considers the influence of these variables, we employ Latin hypercube design to obtain the response surface model and analyze the influence of these variables. Finally we obtain the magnitude of wall thickness of retainer ring and the range of shrink-fit.

Study on Bending-Torsional Coupling Vibration of Intermediate Axis

2012 ◽  
Vol 166-169 ◽  
pp. 3180-3183
Author(s):  
Xue Shi Yao ◽  
Chun Long Zheng
Keyword(s):  
Torsional Vibration ◽  
Dynamic Equations ◽  
Optimized Design ◽  
Modal Shape ◽  
Bending Vibration ◽  
Coupling Vibration ◽  
Centrifugal Load ◽  
Torsional Coupling ◽  
Nature Frequency ◽  
Torsional Frequency

In order to find the cause of the cracked intermediate axis in a transmission,the characteristic of the bending vibration，torsional vibration and bending-torsional coupling vibration were studied through the analysis of the nature frequency and modal shape based on prestress.The results show that the fatigue fracture of the axis is mainly due to the resonant torsional frequency and bending-torsional coupling vibration and It is basically demonstrated by experiment.It has been found that the fundamental frequency is increase with the increase in spin axis velocity because of the centrifugal load i.e.prestress.The effets can be accounted for by an adjustment of the stiffness,and the dynamic equations are derived.In the end,it is made the optimized design on the axis,the low inherent frequencies are optimized in order to avoid resonance.The problem of the cracked intermediate axis has been solved.

Parametric Bird Strike Study of a Transonic Rotor Using Isogeometric Analysis

2016 ◽  
Author(s):  
Sam Duckitt ◽  
Chiara Bisagni ◽  
Shahrokh Shahpar
Keyword(s):  
Isogeometric Analysis ◽  
Control Points ◽  
Bird Strike ◽  
Transonic Compressor ◽  
Mechanical Constraints ◽  
Compressor Rotor ◽  
Centrifugal Load ◽  
Design Variables ◽  
Particle Hydrodynamics ◽  
The Impact

This paper investigates the use of isogeometric analysis (IGA) to study high velocity impact on a transonic compressor rotor resulting from a bird strike. An approach is developed for creating volumetric NURBS blade models which are suitable for IGA. A newly implemented 3D solid NURBS element within the development version of LS-Dyna is validated against finite elements for the NASA rotor 37 under a steady centrifugal load. The smoothed particle hydrodynamics (SPH) method is then used to simulate impact from a bird strike. As a preliminary assessment for multi-disciplinary optimisation (MDO), with the objective to improve aerodynamic performance whilst satisfying mechanical constraints from impact, a number of different blade designs are created by modifying the NURBS control points directly. Hence the control points used in analysis can also be used in the design space. This approach eliminates the need for re-meshing, highlighting the advantages that IGA can bring to design optimisation, since without filtering, moving finite element nodes can result in non-smooth geometries. NURBS parametrisations are also more efficient resulting in fewer design variables, thereby accelerating the optimisation process. The effect of blade sweep, lean, twist and thickness on the impact response are investigated. The results in this paper show the promise that IGA holds in this field but some limitations of the current LS-Dyna implementation are also discussed.

Transient Rotordynamic Modeling of Rolling Element Bearing Systems

2001 ◽  
Author(s):  
A. Liew ◽  
N. S. Feng ◽  
E. J. Hahn
Keyword(s):  
Rolling Element Bearing ◽  
Hertzian Contact ◽  
Centrifugal Load ◽  
Linear Behavior ◽  
Deep Groove ◽  
Rolling Element ◽  
Rolling Elements ◽  
Load Effects ◽  
Element Bearing ◽  
Bearing Preload

Non-linearity effects in rolling element bearings may arise from the Hertzian contact force deformation relationship, the presence of clearance between the rolling elements and the bearing races, and the bearing to housing clearance. Assuming zero bearing to housing clearance and ignoring rolling element centrifugal load effects, it has been shown in earlier work that Rotor Bearing Systems (RBSs) with deep groove ball bearings can give rise to non-linear behavior such as chaotic motion and jump. This paper extends the bearing model to include rolling element centrifugal load, angular contacts and axial dynamics. The effect of more sophisticated bearing models is illustrated in both a rigidly supported rigid RBS and a flexibly supported flexible RBS, the latter being a model of a test rig designed to simulate an aircraft mounted accessory drive unit. Results are presented on the effect of bearing preload on the unbalance response up to a speed of 18,000 rpm.

Dynamic Modelling of Deep-Water Riser With Slug Flow Based on ALE-ANCF

2020 ◽  
Author(s):  
Depeng Liu ◽  
Shangmao Ai ◽  
Liping Sun
Keyword(s):  
Slug Flow ◽  
High Speed ◽  
Dynamic Modelling ◽  
Internal Flow ◽  
Bending Moment ◽  
Time Domain Analysis ◽  
Load Model ◽  
Centrifugal Load ◽  
Load Component ◽  
Euler Bernoulli Beam

Abstract The internal flow in gas-liquid mixing riser often displays a flow pattern known as slug flow, in which gas and liquid are alternately distributed. Dynamic effects due to slug flow is normally most obvious in areas along the riser with high curvature, which is caused by the centrifugal load component. The global riser response to this excitation can be predicted by nonlinear time domain analysis using the load model as described for slug flow conditions. In this study, the riser with internal slug flow is modeled under the framework of Arbitrary-Lagrange-Euler (ALE) description by using the Absolute Node Coordinate Formula (ANCF). The riser is discretized into ANCF cable element based on the Euler-Bernoulli beam assumption, while one-dimensional moving medium modeling method with time-varying density is used to model slug element. Compared with other FEA models of riser subjected to internal flow, the ALE-ANCF model allow easily modeling of complex mass flow and has the advantages of high speed and high precision in handling large deformation of riser, especially for the compliant riser configurations. Numerical simulations of two simplified models are carried out to validate the developed model, then the dynamic response such as displacement, tension force and bending moment of the riser conveying slug flow are analyzed.

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