Formation of Steady Dimples in Point TEHL Contacts

2000 ◽  
Vol 123 (1) ◽  
pp. 42-49 ◽  
Author(s):  
P. Yang ◽  
S. Qu ◽  
M. Kaneta ◽  
H. Nishikawa
Keyword(s):  
Complete Solution ◽  
Elastohydrodynamic Lubrication ◽  
Experimental Results ◽  
Major Radius ◽  
Theoretical Results ◽  
Good Agreement ◽  
Contact Ellipse

Experimental results of steady dimples measured in elliptical glass-steel contact under pure sliding conditions are presented. It is found that two dimples connected with a shallower furrow are generated, each near an end of the major radius of the contact ellipse. The complete solution of the corresponding thermal elastohydrodynamic lubrication (TEHL) problem is calculated numerically. Good agreement is obtained between the experimental and theoretical results. This agreement can be explained by the temperature-viscosity wedge mechanism. Correctness of this mechanism is demonstrated using additional experiments with ceramic balls in contact with glass and sapphire disks.

Pressure Broadening of the Microwave Absorption Lines of Oxygen

1973 ◽  
Vol 51 (22) ◽  
pp. 2329-2331 ◽  
Author(s):  
Y. Yamamoto ◽  
M. Cattani
Keyword(s):  
Microwave Absorption ◽  
Quadrupole Moment ◽  
Microwave Spectrum ◽  
The Self ◽  
Experimental Results ◽  
Dispersion Interactions ◽  
Pressure Broadening ◽  
Line Widths ◽  
Theoretical Results ◽  
Good Agreement

We calculate the line widths for the self-broadening of the microwave spectrum of oxygen taking into account simultaneously quadrupole–quadrupole and dispersion interactions. Our theoretical results are compared with the more recent experimental results. A good agreement is obtained between them if the oxygen quadrupole moment is taken as Q = 1.21 ± 0.05 D Å.

Surface Roughness Effects in High-Speed Hydrodynamic Journal Bearings

1997 ◽  
Vol 119 (4) ◽  
pp. 776-780 ◽  
Author(s):  
H. Hashimoto
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Reynolds Equation ◽  
Computation Time ◽  
Experimental Results ◽  
Roughness Effects ◽  
Modified Reynolds Equation ◽  
Nonlinear Simultaneous Equations ◽  
Theoretical Results ◽  
Good Agreement

This paper describes an applicability of modified Reynolds equation considering the combined effects of turbulence and surface roughness, which was derived by Hashimoto and Wada (1989), to high-speed journal bearing analysis by comparing the theoretical results with experimental ones. In the numerical analysis of modified Reynolds equation, the nonlinear simultaneous equations for the turbulent correction coefficients are greatly simplified to save computation time with a satisfactory accuracy under the assumption that the shear flow is superior to the pressure flow in the lubricant films. The numerical results of Sommerfeld number and attitude angle are compared with the experimental results to confirm the applicability of the modified Reynolds equation in the case of two types of bearings with different relative roughness heights. Good agreement was obtained between theoretical and experimental results.

scholarly journals Theoretical and Experimental Study of Optimization of Polarization Spectroscopy for the D2 Closed Transition Line of 87Rb Atoms

2021 ◽  
Vol 11 (16) ◽  
pp. 7219
Author(s):  
Jeongyoun Jeong ◽  
Sanglok Lee ◽  
Sungi Hwang ◽  
Jaeuk Baek ◽  
Heung-Ryoul Noh ◽  
...  
Keyword(s):  
Pump Beam ◽  
Experimental Results ◽  
Transition Line ◽  
Matrix Equations ◽  
Optimal Parameters ◽  
Cell Temperature ◽  
Vapor Cell ◽  
Polarization Spectroscopy ◽  
Theoretical Results ◽  
Good Agreement

We experimentally and theoretically investigated the optimal condition of polarization spectroscopy for frequency stabilization on various pump beam intensities and vapor cell temperatures for the D2 closed transition line of 87Rb atoms. We compared the experimental results, such as the amplitude, width, and slope, of the polarization spectroscopy signal with the theoretical results obtained from the numerical calculation of temporal density matrix equations. Based on the results, we found the optimal parameters, such as the pump beam intensity and vapor cell temperature, for polarization spectroscopy. The theoretically expected optimal parameters were, qualitatively, in good agreement with the experimental results.

INVESTIGATION OF THE ENTROPY AND SPECIFIC HEAT CAPACITY OF GaN USING INCOMPLETE GAMMA FUNCTIONS

2008 ◽  
Vol 22 (30) ◽  
pp. 5349-5355 ◽  
Author(s):  
SAVAŞ SÖNMEZOǦLU
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Experimental Results ◽  
Analytical Relation ◽  
Gamma Functions ◽  
Temperature Range ◽  
Incomplete Gamma Functions ◽  
Theoretical Results ◽  
Good Agreement

The aim of this paper is to provide validity and reliable analytical relation for the thermodynamic functions calculated in terms of the Debye temperature using incomplete gamma functions, and examines the entropy and specific heat capacity of hexagonal single crystals of GaN in the 0–1800 K temperature range. The obtained results have been compared with the corresponding experimental and theoretical results. Our results are in excellent agreement with the theoretical results over the entire temperature range. It has also shown that at low temperature, our results are in very good agreement with the experimental results, however, at high temperature, our results are lower than other experimental results.

scholarly journals Analysis and Experimental Study on Bearing Capacity of “All-Inclusive” Underpinning Joint

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Kefeng Yue ◽  
Lei Yan
Keyword(s):  
Bearing Capacity ◽  
Experimental Results ◽  
Calculation Formula ◽  
Connection Method ◽  
New Type ◽  
Punching Failure ◽  
Simplified Calculation ◽  
Theoretical Results ◽  
Concrete Interface ◽  
Good Agreement

Aiming at the phenomenon of punching failure and large slip at the new-to-old concrete interface of “beam-column” underpinning joint, a new type of “all-inclusive” underpinning joint is tested and numerically analyzed, which adopts the spraying glue + grooving + planting bars + prestressed + hooping connection method. The experimental and numerical analysis results show that the connection method of “all-inclusive” underpinning joint can effectively avoid punching failure of the joint, and the failure mode is mainly flexure-shear. Then, the “all-inclusive” underpinning joint can delay the initial slip at the new-to-old concrete interface and reduce the overall slip. Finally, combining the theoretical and experimental results, a simplified calculation formula for the bearing capacity of the “all-inclusive” underpinning joint is improved. The theoretical results are in good agreement with the experimental results, which indicates that the calculation of the bearing capacity of the underpinning joint using the formula in this paper is feasible and can provide experimental and theoretical references for similar projects.

scholarly journals Crystal - Rotator-I - Rotator-II Phase Transitions in the Mixtures of Alkanes

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Prabir Kumar Mukherjee
Keyword(s):  
Phase Transitions ◽  
Binary Mixture ◽  
Landau Theory ◽  
Order Parameters ◽  
Experimental Results ◽  
Transition Temperatures ◽  
First Order ◽  
Isotropic Mixing ◽  
Theoretical Results ◽  
Good Agreement

Using the combination of Flory–Huggins theory of isotropic mixing and Landau theory, we discuss the crystal – rotator-I – rotator-II phase transitions in the binary mixture of alkanes. The influence of concentration on the order parameters and the transition temperatures is discussed. Theoretical results show the first order character of both the rotator-I to crystal and rotator-II to rotator-I phase transitions in the mixture of alkanes. A good agreement between theoretical and experimental results are presented in this paper.

Computing and Analyzing the Sensitivity of Radial-Basis Function Neural Network

2013 ◽  
Vol 321-324 ◽  
pp. 1957-1961
Author(s):  
Jie Li ◽  
Jun Li ◽  
Ying Liu
Keyword(s):  
Neural Network ◽  
Radial Basis Function ◽  
Uniform Distribution ◽  
Basis Function ◽  
Experimental Results ◽  
Radial Basis ◽  
The Relationship ◽  
Theoretical Results ◽  
Input Error ◽  
Good Agreement

This paper proposes an algorithm to compute the sensitivity of the Radial-Basis Function Neural Network (RBFNN) due to the errors of the inputs and others parameters of the net works. For simplicity and practicality, all inputs and weights are assumed to be independent and identically distributed (i.i.d) with uniform distribution. A number of simulations are conducted and the good agreement between the experimental results and the theoretical results verifies the reliability and feasibility of the proposed algorithm. The relationship between the sensitivity of RBFNN and input error and the perturbation of others parameters is given.

The Elastic Moduli of Heterogeneous Materials

1962 ◽  
Vol 29 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Zvi Hashin
Keyword(s):  
Approximate Method ◽  
Elastic Moduli ◽  
Heterogeneous Materials ◽  
Theory Of Elasticity ◽  
Experimental Results ◽  
Two Phase ◽  
Concentric Spheres ◽  
Theoretical Results ◽  
Nonhomogeneous Materials ◽  
Good Agreement

Bounds and expressions for the elastic moduli of two or many phase nonhomogeneous materials are obtained by an approximate method based on the variational theorems of the theory of elasticity and on a concentric-spheres model. Theoretical results are in good agreement with experimental results for a two-phase alloy.

Modeling and Experimental Verification of a Hybrid Energy Harvester Using Piezoelectric and Electromagnetic Technologies

2012 ◽  
Vol 569 ◽  
pp. 529-532 ◽  
Author(s):  
Zhen Long Xu ◽  
Xiao Xi Wang ◽  
Xiao Biao Shan ◽  
Tao Xie
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Maximum Output Power ◽  
Experimental Results ◽  
Maximum Output ◽  
Hybrid Energy ◽  
Energy Harvesters ◽  
Hybrid Energy Harvester ◽  
Theoretical Results ◽  
Good Agreement

This paper presents a hybrid energy harvester using piezoelectric (PZT) and electromagnetic (EM) technologies. A mathematical model of the output power for this generator was developed. Experiments were carried out to verify the numerical analysis. The theoretical results were in good agreement with the experimental results. The experimental results showed that the maximum output power of the separate PZT and EM energy harvesters were 0.667 mW and 0.32 mW, while that of the hybrid harvester was 0.845 mW under the vibration acceleration of 9.8 m/s2 at 66 Hz. It shows that the hybrid energy harvester can effectively increase the output power.

Analysis of EHL Circular Contact Start Up: Comparison With Experimental Results

2005 ◽  
Author(s):  
Jiaxin Zhao
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Contact Geometry ◽  
Experimental Results ◽  
Contact Interface ◽  
Solid Contact ◽  
Start Up ◽  
Lubrication Performance ◽  
Lubricated Contact ◽  
Thickness Variations ◽  
Good Agreement

In this paper, the start up condition in elastohydrodynamic lubrication was studied on a steel ball on glass disc contact lubricated with a mineral oil, using a previously developed mixed phase lubrication contact model. The numerical simulation demonstrated the contact geometry change in the transition from initial solid contact to final fully lubricated contact, as well as the load sharing variation between lubricated and solid contacts during the start up. The numerical results of contact geometry was then compared with an experimental study of the same start up situation published by Glovnea and Spikes [1]. The film thickness variations and the propagation of the solid-lubricated contact interface during the start up were compared. Furthermore, an analytical result of the propagation of the solid-lubricated contact interface was also generated by assuming the dominance of the wedge and squeeze terms in the Reynolds Equation, and was also compared with the numerical and experimental results. Good agreement exists among the analytical, numerical and experimental results. The good agreement proves the numerical model as a valid tool in studying the start up condition in elastohydrodynamic lubrication as the transition from solid contact to lubricated contact is of great importance when investigating the start up process and its effects on the overall lubrication performance.

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