Thermohydrodynamic Analysis of High-Speed Water-Lubricated Spiral Groove Thrust Bearing Using Cavitating Flow Model

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Xiaohui Lin ◽  
Shuyun Jiang ◽  
Chibin Zhang ◽  
Xiang Liu
Keyword(s):  
Temperature Rise ◽  
High Speed ◽  
Thrust Bearing ◽  
Cavitating Flow ◽  
Maximum Temperature ◽  
Static Characteristics ◽  
Spiral Groove ◽  
Bubble Volume ◽  
Cavitation Effect ◽  
Bubble Number

A thermohydrodynamic lubrication model of turbulent cavitating flow for high-speed spiral groove thrust bearing was developed considering the effects of cavitation, turbulence, inertia, breakage, and coalescence of bubbles. Comparing with the classical thermohydrodynamic model, this model can predict not only the distributions of pressure and temperature rise but also the distribution of bubble volume and bubble number density. Static characteristics of the water-lubricated spiral groove thrust bearing in the state of turbulent cavitating flow were analyzed, and the influences of multiple effects on the static characteristics of the bearing were researched. The numerical calculation result shows that the bubbles are mainly distributed in inlet and outlet of the spiral groove, the distribution of bubble volume is skewed under the equilibrium state, and small bubbles account for a large proportion of the cavitating flow under high-speed condition. Furthermore, the load carrying capacity and the leakage flow of the bearing decrease due to the effect of cavitation under high-speed. The maximum temperature rise of the bearing decreases due to the effect of cavitation effect.

scholarly journals Dynamic Characteristics of High-speed Water-lubricated Spiral Groove Thrust Bearing based on Turbulent Cavitating Flow Lubrication Model

2020 ◽  
Author(s):  
Xiaohui Lin ◽  
shun Wang ◽  
shuyun Jiang ◽  
shaowen Zhang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Cavitating Flow ◽  
Spiral Groove ◽  
Two Phase ◽  
Damping Coefficients ◽  
Stiffness Coefficients ◽  
Cavitation Effect ◽  
Experimental Apparatus ◽  
Rotary Speed

Abstract In this paper, a turbulent cavitating flow lubrication model based on two-phase fluid and population balance equation of bubbles was established to analyze dynamic characteristics of high speed water-lubricated spiral groove thrust bearings(SGTB). Stiffness and the damping coefficients of the SGTB were calculated using the perturbation pressure equations. An experimental apparatus was developed to verify the theoretical model. Simulating and experimental results show that the small-sized bubbles tend to generate in the turbulent cavitating flow when at a high rotary speed, and the bubbles mainly locate at the edges of the spiral groove. The simulating results also show that the direct stiffness coefficients are increased due to cavitation effect, and cross stiffness coefficients and damping coefficients are hardly affected by the cavitation effect. Turbulent effect on the dynamic characteristics of SGTB is much stronger than the cavitating effect.

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.

Study of Cavitation Bubbles Evolution for High-Speed Water-Lubricated Spiral Groove Thrust Bearings

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Xiaohui Lin ◽  
Ruiqi Wang ◽  
Shaowen Zhang ◽  
Chibin Zhang ◽  
Shuyun Jiang
Keyword(s):  
Theoretical Model ◽  
High Speed ◽  
Groove Depth ◽  
Skewed Distribution ◽  
Outer Diameter ◽  
Spiral Groove ◽  
High Rotational Speed ◽  
Cavitation Bubbles ◽  
Bubble Evolution ◽  
Bubble Number

The purpose of this study is to investigate the evolution of cavitation bubbles for the high-speed water-lubricated spiral groove thrust bearing. A theoretical model of cavitation bubble evolution considering multiple effects (interface, breakage, and coalescence of bubbles) was established for the bearing. A high-speed experimental setup was developed to measure the distribution of bubbles. The theoretical model is verified by the experimental data. The results show that the Boltzmann-type bubble transport equation can be used to describe the bubble evolution of the bearing under the breakup and coalescence at high-speed conditions; the volume of the bubble group presents a skewed distribution in equilibrium; the number of small-sized bubbles is greater than that of large-sized bubbles at high rotational speed; the bubbles are mainly distributed at the inlets and outlets of spiral grooves; the bubble number density increases with the groove depth and spiral angle; more bubbles are generated near the outer diameter of the bearing. The study provides a theoretical and experimental basis for the bubble evolution of the water-lubricated spiral groove bearing under high speeds.

Particularities of Grinding High Speed Steel Punching Tools

2011 ◽  
Vol 325 ◽  
pp. 177-182 ◽  
Author(s):  
Peter Krajnik ◽  
Radovan Drazumeric ◽  
Jeffrey Badger ◽  
Janez Kopač ◽  
Cornel Mihai Nicolescu
Keyword(s):  
Simulation Model ◽  
Material Removal Rate ◽  
Temperature Rise ◽  
Material Removal ◽  
High Speed ◽  
Removal Rate ◽  
High Speed Steel ◽  
Maximum Temperature ◽  
Specific Grinding Energy ◽  
Specific Material

A simulation model of a punch grinding process has been used to determine optimal parameters to reduce grinding cycle time and achieve a constant-temperature no-burn situation. Two basic outputs of the simulation model include arc length of contact and specific material removal rate that are both time-variant. A thermal model is included in the simulation to calculate maximum grinding temperature rise. The simulation-based optimization can help to avoid thermal damage, which includes thermal softening, residual tensile stress, and rehardening burn. The grindability of high speed steel (HSS) is presented in terms of specific grinding energy versus undeformed chip thickness and maximum temperature rise versus specific material removal rate. It is shown that for a given specific material removal rate lower temperatures are achieved when grinding fast and shallow. Higher temperatures, characteristic for slow and deep grinding, soften the material leading to a lower specific grinding energy, especially if grinding is timid. Lowest values of specific grinding energy can be achieved in fast and shallow grinding at aggressive grinding conditions.

Comparative Study on Static Characteristics of Double-Pad Inwardly and Outwardly Pumping Water-Lubricated Spiral-Groove Thrust Bearings

2021 ◽  
Vol 143 (10) ◽  
Author(s):  
Shaowen Zhang ◽  
Shuyun Jiang
Keyword(s):  
Axial Load ◽  
High Speed ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Operating Conditions ◽  
Static Characteristics ◽  
Spiral Groove ◽  
Thrust Bearings ◽  
Axial Load Capacity ◽  
Better Than

Abstract The purpose of this technical brief is to investigate comparatively the static characteristics of the double-pad inwardly pumping and outwardly pumping water-lubricated spiral-groove thrust bearings (SGTBs). Firstly, a thermo-hydrodynamic lubrication model including the cavitating, centrifugal, and turbulent effects is established for the double-pad water-lubricated SGTB operating at a high-speed condition. Subsequently, the film thickness and volume flowrate are verified by an experimental study for the high-speed water-lubricated SGTBs. Finally, the effects of the operating conditions and configuration parameters on the static characteristics of the double-pad inwardly pumping and outwardly pumping SGTBs are analyzed systematically. The simulated results show that when the radius ratio exceeds 0.7, the outwardly pumping SGTB can perform better than the inwardly pumping version, with good axial load capacity, higher resistance to tilting and always positive radial flowrate.

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