Analysis on the Static Characteristics of the New Type Externally Pressurized Spherical Air Bearings

2010 ◽  
Author(s):  
Fusheng Wang ◽  
Gang Bao
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Structure Design ◽  
Measuring Instruments ◽  
Air Bearings ◽  
Static Characteristics ◽  
Mass Properties ◽  
New Type ◽  
Spherical Air Bearings

The new type externally pressurized spherical air bearings used mass properties measuring instruments are studied which are particularly recommended for determining mass properties of rockets, satellites and ballistic objects. The air bearings are the key component of the mass properties measuring instruments. In order to provide some theoretical guideline for the structure design of the new type externally pressurized spherical air bearings, this paper analyzes static characteristics and the factors affecting the static characteristics of the new type air bearings. A finite volume method is adopted to discretize the three-dimensional steady-state compressible Navier-Stokes equations, and a modified SIMPLE algorithm for compressible fluid is applied to solve the discretized governing equations. The pressure field and velocity field of the air bearings are obtained, from which the carrying capacity, static stiffness and mass flow of the air bearings can be derived, and the factors and rules affecting the static characteristics are analyzed. The calculation method proposed in this paper fits well the general principle, which can be extended to the characteristics analysis of other air bearings.

Research on a New Type of Center of Mass Measuring Instruments

2010 ◽  
Vol 29-32 ◽  
pp. 1722-1727
Author(s):  
Fu Sheng Wang ◽  
Gang Bao
Keyword(s):  
Attitude Control ◽  
Center Of Mass ◽  
Structure Design ◽  
Thin Plates ◽  
Elastic Displacement ◽  
Measuring Instruments ◽  
Satellite Attitude Control ◽  
Mass Properties ◽  
New Type ◽  
Measurement And Control

The accurate measurement and control of center of mass (CM) in mass properties for satellite attitude control are the most important. In order to accurately measure CM, this paper describes a new type of CM measuring instruments which are particularly recommended for determining mass properties of rockets, satellite and ballistic objects. A spherical air-bearing supports a precision rotary table and acts as a frictionless pivot axis for measuring unbalance moments due to the displacement of the test part CM relative to the central axis of the bearing. This paper emphasizes the research on reasons and laws of the load table CM offset caused by the elastic deformation, and according to curve theory of thin plates derives the formulary for the element center of mass displacement of the finite element and for the platform structure center of mass elastic displacement, and calculates the CM elasticity offset and the unbalance moment caused by the deformation of loaded table. The research results provide bases for the structure design of rotary tables.

scholarly journals Numerical Study of the Internal Flow Field of a Centrifugal Impeller

1994 ◽  
Author(s):  
Mou-jin Zhang ◽  
Chuan-gang Gu ◽  
Yong-miao Miao
Keyword(s):  
Flow Field ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Internal Flow ◽  
Staggered Grid ◽  
Navier Stokes ◽  
Centrifugal Impeller ◽  
High Reynolds

The complex three-dimensional flow field in a centrifugal impeller with low speed is studied in this paper. Coupled with high–Reynolds–number k–ε turbulence model, the fully three–dimensional Reynolds averaged Navier–Stokes equations are solved. The Semi–Implicit Method for Pressure–Linked Equations (SIMPLE) algorithm is used. And the non–staggered grid arrangement is also used. The computed results are compared with the available experimental data. The comparison shows good agreement.

THE INVESTIGATION OF THERMOHYDRODYNAMIC CHARACTERISTIC OF SINGLE AXIAL GROOVE JOURNAL BEARINGS WITH FINITE LENGTH BY USING CFD TECHNIQUES

2013 ◽  
Vol 10 (05) ◽  
pp. 1350031 ◽  
Author(s):  
ALIREZA ARAB SOLGHAR ◽  
S. A. GANDJALIKHAN NASSAB
Keyword(s):  
Stokes Equations ◽  
Control Volume ◽  
Three Dimensional ◽  
Theoretical Data ◽  
Simple Algorithm ◽  
Journal Bearings ◽  
Rate Equations ◽  
Navier Stokes ◽  
Computational Domain ◽  
Oil Flow

The three-dimensional steady state thermohydrodynamic (THD) analysis of an axial grooved oil journal bearing is obtained theoretically. Navier–Stokes equations are solved simultaneously along with turbulent kinetic energy and its dissipation rate equations coupled with the energy equation in the lubricant flow and the heat conduction equation in the bush. The AKN low-Re κ–ε turbulence model is used to simulate the mean turbulent flow field. Considering the complexity of the physical geometry, conformal mapping is used to generate an orthogonal grid and the governing equations are transformed into the computational domain. Discretized forms of the transformed equations are obtained by the control volume method and solved by the SIMPLE algorithm. The numerical results of this analysis can be used to investigate the pressure distribution, volumetric oil flow rate and the loci of shaft in the journal bearings. To validate the computational results, comparison with the experimental and theoretical data of other investigators is made, and reasonable agreement is found.

Influence of Rotor-Stator Interaction on Flow Stability in Centrifugal Pump Based on Energy Gradient Method

2016 ◽  
Vol 33 (4) ◽  
Author(s):  
Lu-Lu Zheng ◽  
Hua-Shu Dou ◽  
Wei Jiang ◽  
Xiaoping Chen ◽  
Zuchao Zhu ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Navier Stokes ◽  
Turbulent Model ◽  
Navier Stokes Equations ◽  
Energy Gradient ◽  
Rotor Stator Interaction ◽  
Volume Method

AbstractNumerical simulation is performed for the three-dimensional turbulent flow field in a centrifugal pump by solving the Reynolds-averaged Navier-Stokes equations and the RNG k-epsilon turbulent model. The finite volume method and the SIMPLE algorithm are employed for the solution of the system. All the parameters in the centrifugal pump at different blade angular positions are obtained by simulation. The flow structure is analyzed and the distributions of the energy gradient function

Performance of the Partially Porous and the Fully Porous Aerostatic Journal Bearings with Incompressible Air Flow

2014 ◽  
Vol 625 ◽  
pp. 384-391 ◽  
Author(s):  
Te Yen Huang ◽  
Shao Yu Hsu ◽  
Bo Zhi Wang ◽  
Sheam Chyun Lin
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Stokes Equations ◽  
Volume Flow Rate ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Journal Bearings ◽  
Coupling Scheme ◽  
Output Pressure

This report presents a study on the performance of the fully porous and the partially porous aerostatic journal bearings. Based on the finite volume method and the pressure-velocity coupling scheme of the SIMPLE algorithm with the standard k-ε turbulent model, this study utilized the CFD software to solve the incompressible three dimensional Navier-Stokes equations to calculate the pressure of the flow field in the bearings. The effects of the size of the porous medium, the bearing gap, the eccentric ratio and the rotational speed of the spindle on the characteristics of the bearing such as the pressure distribution, the load carrying capacity and the stiffness were investigated. The computed results revealed that, when the spindle rotated at high speed, the effect of the dynamic pressure became dominant, while the effect of the static pressure became insignificant. Among the three types of journal bearings under investigation, the partially porous aerostatic journal bearing exhibited the highest ratio of output pressure to air volume flow rate. It indicated that, in terms of operational efficiency, the partially porous aerostatic journal bearing is superior to the fully porous aerostatic journal bearing.

Design of Body Structure for New Type Lightweight Electric Vehicle

2014 ◽  
Vol 620 ◽  
pp. 335-340 ◽  
Author(s):  
Li Xia Wang ◽  
Tian Feng Zhao ◽  
Jian Bo Cao ◽  
Ji Feng Shen ◽  
Yan Bin Xiao ◽  
...  
Keyword(s):  
Energy Saving ◽  
Electric Vehicle ◽  
Three Dimensional ◽  
Structure Design ◽  
The Body ◽  
Vehicle Body ◽  
Body Structure ◽  
Three Dimensional Modeling ◽  
Body Design ◽  
New Type

Considering the efficient use of energy and environmental pollution, people's lives tend to energy saving and environmental protection, and energy saving electric vehicles has gradually been widely used. Through combining theoretical analysis, numerical simulation, system design and experimental validation, based on studying electric vehicle body design principles, the experiment optimized electric vehicle body design, and reduced the weight of the vehicle effectively. Its performance becomes more advanced, and the application becomes more economical and safe. By using Solidworks software, lightweight electric vehicle body structure of two-dimensional design and three-dimensional modeling was built to reach practical requirements. The body structure design is original and simple, which has good practical value.

Numerical Simulation and Experiment Research on Pressure Fluctuation and Aerodynamic Noise Field of a Multi-Blade Centrifugal Fan

2012 ◽  
Vol 468-471 ◽  
pp. 2231-2234
Author(s):  
Feng Gao ◽  
Wei Yan Zhong
Keyword(s):  
Numerical Simulation ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Aerodynamic Noise ◽  
Navier Stokes ◽  
Computational Domain ◽  
Centrifugal Fan ◽  
Navier Stokes Equations ◽  
Simulation And Experiment

Numerical simulation of the three-dimensional steady and unsteady turbulent flow in the whole flow field of a multi-blade centrifugal fan is performed. Unstructured grids is used to discrete the computational domain. Pressure boundary conditions are specified to the inlet and the outlet. The SIMPLE algorithm in conjunction with the RNG k-ε turbulent model is used to solve the three-dimensional Navier-Stokes equations. The moving reference frame is adopted to transfer data between the interfaces of the rotating field and the stationary field. Based on the calculation of the inner-flow in the fan, the pressure pulsation of some important monitoring points and the aerodynamic noise distribution, banding together experiment data were farther analyzed The simulation results are of important significance to the optimal design and noise control of the fan.

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