CFD Research on Aerostatic Bearing with Tangential Supply Holes

2010 ◽  
Vol 97-101 ◽  
pp. 2021-2026 ◽  
Author(s):  
He Chun Yu ◽  
Wen Qi Ma ◽  
Zu Wen Wang ◽  
Li Fang Xu
Keyword(s):  
Load Capacity ◽  
Dynamic Effect ◽  
Three Dimension ◽  
Static Characteristics ◽  
Pressure Distributions ◽  
Theoretical Support ◽  
Gas Consumption ◽  
Aerostatic Bearings ◽  
Volume Method ◽  
Gas Supply

The radial aerostatic bearings with reversely tangential gas supply holes have been proved successfully in some applications to improve the dynamic stability. However, the concept lacks firm theoretical support. Aerostatic bearings with reversely tangential gas supply holes and radial gas supply holes were designed. The finite volume method (FVM) was used to solve the three-dimension flow field, the static characteristics of them were studied, and the following conclusions were drawn: The tangential gas supply holes can improve the pressure distributions in the working clearance, but they can’t effectively improve the load capacity and stiffness. The improvement of the characteristics of aerostatic bearings with tangential gas supply holes is at the expense of excessive gas consumption. For aerostatic bearings, when the eccentricity ( ) is large and the rotor speed ( ) is high, the dynamic effect can effectively improve the load capacity and stiffness.

Three-Dimensional CFD Simulation for Water-Lubricated Guide Bearing of Large Tubular Pump

2014 ◽  
Vol 574 ◽  
pp. 160-166
Author(s):  
Hua Rong Xin ◽  
Ming Yue Zhang
Keyword(s):  
Cfd Simulation ◽  
Pressure Effect ◽  
Load Capacity ◽  
Dynamic Pressure ◽  
Water Pressure ◽  
Three Dimensional ◽  
Water Film ◽  
Static Characteristics ◽  
Pressure Distributions ◽  
High Speeds

A numerical simulation for flow field in water-lubricated guide bearing of large tubular pump is conducted by software Fluent, which shows the pressure distribution of water film with different rotating speeds and the rule of the influence of relevant parameters on the amount of lubricating water, dynamic and static characteristics of guide bearing.The result shows that the pressure distributions of water film at low and high speeds are very different, and with the obvious dynamic pressure effect, the bearing inner can be in a state of reflux and the water-lubricated amount and clearance are reduced. The load capacity and stiffness of guide bearing are increased along with the speed and water pressure increase meanwhile the amount of water is increased along with the speed lowering and the water pressure and clearance increase.

An Experimental Study on Externally Pressurized Supersonic Gas Thrust Bearings

1985 ◽  
Vol 107 (1) ◽  
pp. 122-127 ◽  
Author(s):  
Yutaka Miyake ◽  
Takehiko Inaba ◽  
Naoshige Kubo ◽  
Jun-ichi Takeoka
Keyword(s):  
Experimental Study ◽  
Flow Rate ◽  
Load Capacity ◽  
Experimental Results ◽  
Static Characteristics ◽  
Thrust Bearings ◽  
Pressure Distributions ◽  
Theoretical Predictions ◽  
New Type ◽  
Good Agreement

Externally pressurized supersonic gas thrust bearings whose generation of load capacity is substantially independent of the viscosity of working fluids, have been proposed and analyzed by the authors. This report presents the experimental results of the static characteristics of this new type of bearings. The experimental results including load capacity, stiffness, mass flow rate, and pressure distributions in the bearing clearance, generally show a good agreement with the theoretical predictions and verify the validity of this new bearing. The effect of an orifice to improve the stiffness is also examined. Some problems which should be solved to put the bearing in practical use are pointed out.

Investigating the influences of pressure-equalizing grooves on characteristics of aerostatic bearings based on CFD

2019 ◽  
Vol 71 (7) ◽  
pp. 853-860
Author(s):  
Ruzhong Yan ◽  
Liaoyuan Wang ◽  
Shengze Wang
Keyword(s):  
Optimization Design ◽  
Load Capacity ◽  
Static Characteristic ◽  
Aerostatic Bearing ◽  
Content Type ◽  
Distribution Form ◽  
Pressure Distributions ◽  
Static Performance ◽  
Ultra Precision ◽  
Aerostatic Bearings

Purpose The purpose of this study is to reveal the influence law of pressure-equalizing grooves on aerostatic bearings and improve the static performance of bearings by optimizing the distribution form of grooves. Design/methodology/approach In view of two kinds of common restrictor distribution forms on the thrust surface, the linear and the rectangular, six kinds of pressure-equalizing groove schemes were proposed – the line-shape, the extended-shape, the S-shape, the oblong-shape, the X-shape and the reticular-shape. Based on the analysis of lubrication theory of the orifice-type aerostatic bearing, the numerical simulations of different bearings were carried out. The pressure distributions and static characteristic curves of different bearings were obtained. Findings The study reveals that the adoption of the pressure-equalizing grooves can substantially improve the load capacity and static stiffness of the bearing and make the bearing maintain a uniform stress, which enhances operating accuracy and life of the bearing. The superior function of the reticular-shape groove is highlighted. Originality/value The research results can effectively guide the optimization design of aerostatic bearings and provide a crucial technical reference for application of ultra-precision aerostatic supporting system.

Research of pressure influence in the gas supply system on the energy consuption level of gas devices

2019 ◽  
Vol 6 (2) ◽  
pp. 56-63
Author(s):  
L. D. Pylypiv ◽  
І. І. Maslanych
Keyword(s):  
Natural Gas ◽  
Residential Buildings ◽  
Supply System ◽  
Normal Operation ◽  
Gas Combustion ◽  
Efficient Operation ◽  
Gas Consumption ◽  
Natural Gas Combustion ◽  
Gas Supply

There are investigated the influence of operating pressures in the gas supply system on the level of such energy indicators as efficiency, gas flow and gas overrun by gas equipment in residential buildings. There is established a relationship between the values of operating pressures in the gas supply system and the gas consumption level of household appliances. The causes of insufficient pressure in the gas networks of settlements are analyzed in the article. There is also developed an algorithm for calculating the change in the efficiency of gas appliances depending on the operational parameters of the gas network. It has been found that the most efficient operation of gas appliances is observed at an overpressure at the inlet of gas appliances of about 1200 Pa.To ensure the required quality of natural gas combustion among consumers and minimize gas consumption there are justified the following measures in the article: coordinating a domestic regulatory framework for assessing the quality of natural gas with international norms and standards; improving the preparation of gas coming from local wells before supplying it to gas distribution networks; auditing low pressure gas pipelines and reconstructing areas affected by corrosion; ensuring standard gas pressure in the network for the normal operation of domestic gas appliances; stating quality indicators of natural gas combustion by gas sales organizations.

scholarly journals Design and Analysis of an Aerostatic Pad Controlled by a Diaphragm Valve

Lubricants ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 47
Author(s):  
Federico Colombo ◽  
Luigi Lentini ◽  
Terenziano Raparelli ◽  
Andrea Trivella ◽  
Vladimir Viktorov
Keyword(s):  
Sensitivity Analysis ◽  
High Precision ◽  
Load Capacity ◽  
Design Procedure ◽  
Maximum Load ◽  
Air Gap ◽  
Diaphragm Valve ◽  
Compensation Methods ◽  
Aerostatic Bearings ◽  
Gap Height

Because of their distinctive characteristics, aerostatic bearings are particularly suitable for high-precision applications. However, because of the compressibility of the lubricant, this kind of bearing is characterized by low relative stiffness and poor damping. Compensation methods represent a valuable solution to these limitations. This paper presents a design procedure for passively compensated bearings controlled by diaphragm valves. Given a desired air gap height at which the system should work, the procedure makes it possible to maximize the stiffness of the bearing around this value. The designed bearings exhibit a quasi-static infinite stiffness for load variation ranging from 20% to almost 50% of the maximum load capacity of the bearing. Moreover, the influence of different parameters on the performance of the compensated pad is evaluated through a sensitivity analysis.

Numerical and experimental studies on the thermal and static characteristics of multi-leaf foil thrust bearing

2021 ◽  
pp. 135065012110110
Author(s):  
Yu Guo ◽  
Yu Hou ◽  
Qi Zhao ◽  
Xionghao Ren ◽  
Shuangtao Chen ◽  
...  
Keyword(s):  
High Speed ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Failure Process ◽  
Experimental Studies ◽  
Elastic Model ◽  
Static Characteristics ◽  
Bearing Load ◽  
Foil Thrust Bearing ◽  
Cooling Air

Foil bearing is considered to be a promising supporting technology in high-speed centrifugal machinery. Due to the high-speed shearing effect in the viscous lubricant film, heat generation could not be ignored. In this paper, a thermo-elastic model of the multi-leaf foil thrust bearing is proposed to predict its thermal and static characteristics. In the model, modified Reynolds equation, energy equation, and Kirchhoff equation are solved in a coupling way. The contact area between the foil and welding plate is taken into account. Besides, the effect of cooling air on the bearing temperature is investigated. The ultimate load capacity and transient overload failure process of the bearing is analyzed and discussed. The effect of rotation speed on the bearing temperature is more obvious than that of the bearing load. The bearing temperature drops obviously by introducing the cooling air, and the cooling effect is improved with the supply pressure. The transient overload failure of the bearing occurs when the bearing load exceeds the ultimate value.

Influence of Diameter and Number of Orifice on Static Characteristics of Radial-Thrust Aerostatic Bearing

2012 ◽  
Vol 497 ◽  
pp. 78-82
Author(s):  
Fei Hu Zhang ◽  
Sheng Fei Wang ◽  
Qiang Zhang ◽  
Peng Qiang Fu
Keyword(s):  
Machine Tool ◽  
Fluid Dynamic ◽  
Load Capacity ◽  
Large Diameter ◽  
Orifice Diameter ◽  
Static Characteristics ◽  
Aerostatic Bearing ◽  
Supporting System ◽  
Manufacturing Technologies ◽  
Radial Thrust

The working performance of the spindle system is the most important factor to embody the overall performance of the machine tool. To ensure the advanced capabilities, besides the high-precision manufacturing technologies, it is mainly depending on the bearing module and the forces on the spindle. In this paper, a new strategy of the vertical spindle supporting system is presented to meet the high stiffness requirement for the aerostatic bearing. Based on the computational fluid dynamics and finite volume method, a fluid dynamic model and structure model of the large diameter incorporate radial-thrust aerostatic bearing is developed and simulated to find out the pressure distribution laws of the spindle supporting system. The grid subdivision in the direction of film thickness is paid more attentions when establishing the grid of the whole gas film. Simulation results show that this special structure of bearing module can supply enough load capacity and stiffness for the machine tool. The results also indicate that the static characteristics of the bearing are improved as the supply pressure increases and as the supply orifice diameter decreases.

An Economic Alternative to Replacing Centralized Gas Supply with Autonomous Biogas Facilities in Russian Cities

2021 ◽  
Vol 20 (3) ◽  
pp. 582-612
Author(s):  
G. S. Chebotareva ◽  
◽  
A. A. Dvinayninov ◽  
Keyword(s):  
Economic Efficiency ◽  
Clean Energy ◽  
State Regulation ◽  
Biogas Plant ◽  
Main Trend ◽  
Effective Response ◽  
Biogas Plants ◽  
Gas Consumption ◽  
Gas Supply ◽  
Climatic Features

The main trend in energy development is to increase energy efficiency by reducing the use of limited natural resources, the spread of renewable energy, and reducing the negative impact on the environment. An effective response to these challenges is the use of biogas plants that produce clean energy and solve the environmental problems of waste disposal and recycling. The purpose of the article is to assess the economic efficiency of replacing district gas supply with autonomous biogas plants in public utilities. A hypothesis has been put forward that the feasibility of using such technologies depends on climatic features and the specific provisions of state regulation of prices and gas consumption rates. A cost approach was applied that assesses the overall structure of equipment costs, as well as a comparative assessment method according to the principle “with / without a biogas plant”, and a scenario analysis, the criterion of which is the size of the family owning the plant. An auxiliary method for forecasting retail and economically justified prices for natural gas for the population was used. The object of calculations is the “HomeBiogas” installation intended for home use. Three Russian cities were chosen as territorial subjects: Yekaterinburg, Irkutsk and Krasnodar. The cities which differ significantly in their natural characteristics and approaches to the formation of retail gas prices. It has been proved that although the average monthly temperatures differ significantly in the cities considered, none of them has a constant temperature exceeding the required standard value of 17°C. In each case, the initial capital investment is driven up by the cost of installing additional insulation and heating systems. This equalizes the costs of warmer and colder areas. Therefore, the climatic features of cities are not significant and do not affect the economic efficiency of using a biogas plant. In turn, state regulation of prices and norms of gas consumption by the population is of decisive importance. The findings are of theoretical and practical importance. The methodology can be applied to assess the efficiency of using biogas plants in industry and gasification projects in the remote areas of Russia.

Rotordynamics Performance of Hybrid Foil Bearing Under Forced Vibration Input

2017 ◽  
Author(s):  
Daejong Kim ◽  
Brian Nicholson ◽  
Lewis Rosado ◽  
Garry Givan
Keyword(s):  
Impulse Response ◽  
High Speed ◽  
Load Capacity ◽  
Supply System ◽  
Forced Response ◽  
Experimental Results ◽  
Lateral Acceleration ◽  
Foil Bearings ◽  
Foil Bearing ◽  
Gas Supply

Foil bearings are one type of hydrodynamic air/gas bearings but with a compliant bearing surface supported by structural material that provides stiffness and damping to the bearing. The hybrid foil bearing (HFB) in this paper is a combination of a traditional hydrodynamic foil bearing with externally-pressurized air/gas supply system to enhance load capacity during the start and to improve thermal stability of the bearing. The HFB is more suitable for relatively large and heavy rotors where rotor weight is comparable to the load capacity of the bearing at full speed and extra air/gas supply system is not a major added cost. With 4,448N∼22,240N thrust class turbine aircraft engines in mind, the test rotor is supported by HFB in one end and duplex rolling element bearings in the other end. This paper presents experimental work on HFB with diameter of 102mm performed at the US Air force Research Laboratory. Experimental works include: measurement of impulse response of the bearing to the external load corresponding to rotor’s lateral acceleration of 5.55g, forced response to external subsynchronous excitation, and high speed imbalance response. A non-linear rotordynamic simulation model was also applied to predict the impulse response and forced subsynchronous response. The simulation results agree well with experimental results. Based on the experimental results and subsequent simulations, an improved HFB design is also suggested for higher impulse load capability up to 10g and rotordynamics stability up to 30,000rpm under subsynchronous excitation.

A Calculation Method to Investigate the Effects of Geometric Parameters and Operational Conditions on the Static Characteristics of Aerostatic Spherical Bearings

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Hailong Cui ◽  
Huan Xia ◽  
Dajiang Lei ◽  
Xinjiang Zhang ◽  
Zhengyi Jiang
Keyword(s):  
Experimental Data ◽  
Calculation Method ◽  
Reynolds Equation ◽  
Geometric Parameters ◽  
Static Characteristics ◽  
Optimal Parameters ◽  
Film Pressure ◽  
Operational Conditions ◽  
Pressure Distributions ◽  
Calculation Results

In this paper, a calculation method based on matlab partial differential equations (PDE) tool is proposed to investigate the static characteristics of aerostatic spherical bearings. The Reynolds equation of aerostatic spherical bearings is transformed into a standard elliptic equation. The effects of geometric parameters and operational conditions on the film pressure, bearing film force, and stiffness are studied. The axial and radial eccentricities result in different film pressure distributions; the bearing film force and stiffness are significantly influenced by geometric parameters and operational conditions. The relative optimal parameters are confirmed based on the calculation results. A comparison between the numerical and experimental results is also presented. The highest relative error between the numerical results and the experimental data is 11.3%; the calculation results show good agreements with the experimental data, thus verifying the accuracy of the calculation method used in this paper.

Sign in / Sign up

Export Citation Format

Share Document