The Profile Development of a Twin-Land Oil-Control Ring During Running-In

1998 ◽  
Vol 120 (3) ◽  
pp. 616-621 ◽  
Author(s):  
M. Visscher ◽  
D. Dowson ◽  
C. M. Taylor
Keyword(s):  
Surface Roughness ◽  
Theoretical Model ◽  
Twist Angle ◽  
Theoretical Modeling ◽  
Experimental Results ◽  
Roughness Height ◽  
Profile Development ◽  
Motored Engine

This paper presents experimental results of motored engine tests on the wear and profile development of a twin-land oil-control ring. It is shown that the roughness height of the plateau honed liner decreases during running-in, indicating that the deeper grooves remain unaffected. The piston lands are much smoother, and do not show a significant overall change in surface roughness. The profile development results are compared with computer predictions in order to verify the theoretical modeling. It is indicated that the worn land profiles remain tapered, with an inclination resembling the twist angle of the ring. However, there remains a difference in the experimental and the numerically predicted land inclinations. This is probably due to the piston tilt, which was not included in the theoretical model.

Changes of Surface Topography During Running-In Process

2004 ◽  
Vol 126 (3) ◽  
pp. 620-625 ◽  
Author(s):  
Yeau-Ren Jeng ◽  
Zhi-Way Lin ◽  
Shiuh-Hwa Shyu
Keyword(s):  
Surface Roughness ◽  
Theoretical Model ◽  
Surface Topography ◽  
Experimental Results ◽  
Wear Model ◽  
Initial Height ◽  
Different Types

This study investigated the surface topographical changes during running-in. A theoretical model, which is composed of Johnson translatory system and a microscopic wear model, was used to describe the changes of surface roughness during running-in for general surfaces. Running-in tests were conducted for engine bores with different surface height distributions in order to understand surface topographical changes and validate the theory. Experimental results show that the theoretical model provides a good indication of changes of surface topography for surfaces with different types of initial height distributions.

A Sliding Microtubule Model Incorporating Axonemal Twist and Compatible with Three-dimensional Ciliary Bending

1979 ◽  
Vol 78 (1) ◽  
pp. 265-280
Author(s):  
M.J. E. HOLWILL ◽  
HOWARD J. COHEN ◽  
PETER SATIR
Keyword(s):  
Theoretical Model ◽  
Electron Micrographs ◽  
Twist Angle ◽  
Three Dimensional ◽  
Experimental Results ◽  
Central Pair ◽  
Metachronal Wave ◽  
Recovery Stroke ◽  
Selection Of

1. Equations are developed to calculate the relative displacements of the doublet microtubules at the tip of a cilium when the microtubules twist about the axis of the organelle. 2. Displacements measured from electron micrographs show asymmetry (or skew) which can be matched quantitatively by the theoretical model with the appropriate selection of twist angle and orientation of the axoneme with respect to the plane of beat. 3. For Elliptio cilia the experimental results are consistent with a planar effective stroke and a recovery stroke involving a three-dimensional bend. The plane of the effective stroke is not normal to a surface containing the central pair of microtubules but contains microtubule 2 to produce the observed skew. 4. This model for the beat also explains the range of orientations of axoneme observed in sections through the metachronal wave.

Actuation and dynamic mechanical characteristics of a core free flat dielectric electro-active polymer soft actuator

2020 ◽  
Vol 14 (4) ◽  
pp. 7396-7404
Author(s):  
Abdul Malek Abdul Wahab ◽  
Emiliano Rustighi ◽  
Zainudin A.
Keyword(s):  
Theoretical Model ◽  
Resonance Frequency ◽  
Dynamic Testing ◽  
Experimental Results ◽  
Percentage Error ◽  
Initial Tension ◽  
Average Percentage ◽  
Soft Actuator ◽  
Average Percentage Error ◽  
Mechanical Dynamics

Various complex shapes of dielectric electro-active polymer (DEAP) actuator have been promoted for several types of applications. In this study, the actuation and mechanical dynamics characteristics of a new core free flat DEAP soft actuator were investigated. This actuator was developed by Danfoss PolyPower. DC voltage of up to 2000 V was supplied for identifying the actuation characteristics of the actuator and compare with the existing formula. The operational frequency of the actuator was determined by dynamic testing. Then, the soft actuator has been modelled as a uniform bar rigidly fixed at one end and attached to mass at another end. Results from the theoretical model were compared with the experimental results. It was found that the deformation of the current actuator was quadratic proportional to the voltage supplied. It was found that experimental results and theory were not in good agreement for low and high voltage with average percentage error are 104% and 20.7%, respectively. The resonance frequency of the actuator was near 14 Hz. Mass of load added, inhomogeneity and initial tension significantly affected the resonance frequency of the soft actuator. The experimental results were consistent with the theoretical model at zero load. However, due to inhomogeneity, the frequency response function’s plot underlines a poor prediction where the theoretical calculation was far from experimental results as values of load increasing with the average percentage error 15.7%. Hence, it shows the proposed analytical procedure not suitable to provide accurate natural frequency for the DEAP soft actuator.

Influence of surface roughness on the wetting angle

1995 ◽  
Vol 10 (8) ◽  
pp. 1984-1992 ◽  
Author(s):  
X.B. Zhou ◽  
J.Th.M. De Hosson
Keyword(s):  
Surface Roughness ◽  
Gaussian Distribution ◽  
Rough Surfaces ◽  
Contact Angles ◽  
Wetting Angle ◽  
Experimental Results ◽  
Solid Surfaces ◽  
Roughness Measurements

A this paper the influence of surface roughness on contact angles in the system of liquid Al wetting solid surfaces of Al2O3 has been studied. It was observed that contact angles of liquid Al vary significantly on different rough surfaces of Al2O3. A model is proposed to correlate contact angles with conventional roughness measurements and wavelengths by assuming a cosine profile of rough grooves with a Gaussian distribution of amplitudes. In comparison with the experimental results, the model provides a good estimate for describing the influence of surface roughness on contact angles of liquid Al on Al2O3.

Divalent Surfactants. Experimental Results and Theoretical Modeling of Surfactant/Water Phase Equilibria

Langmuir ◽  
1994 ◽  
Vol 10 (7) ◽  
pp. 2177-2187 ◽  
Author(s):  
Haakan Hagslaett ◽  
Olle Soederman ◽  
Bengt Joensson
Keyword(s):  
Phase Equilibria ◽  
Theoretical Modeling ◽  
Experimental Results ◽  
Water Phase

scholarly journals Mobility Limitations due to Dislocations and Interface Roughness in AlGaN/AlN/GaN Heterostructure

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Qun Li ◽  
Jingwen Zhang ◽  
Li Meng ◽  
Jing Chong ◽  
Xun Hou
Keyword(s):  
Surface Roughness ◽  
Theoretical Model ◽  
Interface Roughness ◽  
Mobility Limitations ◽  
Gaussian Form ◽  
Quantitative Measurements ◽  
Transmission Electron ◽  
Dimensional Electron Gas ◽  
Exponential Correlation Function ◽  
Gan Heterostructure

The dislocations and surface roughness in an AlGaN/AlN/GaN heterostructure were analyzed by transmission electron microscopy (TEM) and atomic force microscopy (AFM), respectively, and the mobility limitation mechanisms in the two-dimensional electron gas (2DEG) were studied using a theoretical model that took into account the most important scattering mechanisms. An exponential correlation function provides a better description of the statistical properties of surface roughness than the Gaussian form and thus is adopted in the theoretical model. The calculated results are in good agreement with Hall data. The quantitative measurements of dislocations and surface roughness allow the evaluation of the relative importance of each extrinsic scattering mechanism.

scholarly journals Investigation of thermal conductivity of single-wall carbon nanotubes

2011 ◽  
Vol 15 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Mahmoud Jafari ◽  
Majid Vaezzadeh ◽  
Momhamad Mansouri ◽  
Abazar Hajnorouzi
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Theoretical Model ◽  
Potential Energy ◽  
Experimental Results ◽  
Single Wall Carbon Nanotubes ◽  
Lattice Vibrations ◽  
Single Wall Carbon ◽  
Thermal Potential ◽  
Conductivity Behavior

In this paper, the thermal conductivity of Single-wall carbon nanotubes (SWCNTs) is determined by lattice vibrations (phonons) and free elections. The thermal conductivity of SWCNTs is modeled up to 8-300 K and the observed deviations in K-T figures of SWCNTs are explained in terms of phonon vibrations models. An suitable theoretical model is shown for thermal conductivity behavior with respect to temperature and is generalized for experimental results. This model enables us to calculate thermal conductivity SWNTs and Thermal Potential Energy (TPE).

scholarly journals A Stochastic Model for the Fractal Dimension Estimation of Asphaltenes Aggregation

2019 ◽  
Vol 8 (6) ◽  
pp. 1992-1995
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Stochastic Model ◽  
Production Systems ◽  
Experimental Results ◽  
Crude Oils ◽  
Dimension Estimation ◽  
Maximum Value ◽  
Solids Deposition

Some of the problems associated with the transportation of crude oils are due to the presence of heavy compounds as asphaltene molecules. This work developed a stochastic model that predicts the fractal dimension of the asphaltene aggregates. It was found that the maximum value of the fractal dimension is 1.71, which corresponds to the reported experimental results. The model can be applied as a universal growing behavior for the analysis of surface roughness when solids deposition is observed in the production systems involving crude oils

Sign in / Sign up

Export Citation Format

Share Document