The Generating Mechanism of Surface Roughness by Random Cutting Edges

1978 ◽  
Vol 20 (4) ◽  
pp. 197-200
Author(s):  
M. Hasegawa ◽  
T. Tsukizoe
Keyword(s):  
Surface Roughness ◽  
Root Mean Square ◽  
Statistical Approach ◽  
Ground Surface ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Two Dimensional ◽  
Dimensional Distribution

This paper describes a statistical approach for predicting the generating mechanism of the surface roughness produced by random cutting edges. The two-dimensional distribution of the generated surface roughness is derived by considering the distribution of the maxima of the cutting edges. The method is used to determine the root-mean-square roughness of the ground surface.

scholarly journals THE PREDICTION AND OPTIMIZATION OF SURFACE ROUGHNESS IN GRINDING OF S50C CARBON STEEL USING MINIMUM QUANTITY LUBRICATION OF VIETNAMESE PEANUT OIL

2021 ◽  
pp. 1-8
Author(s):  
Van Canh Nguyen ◽  
Tien Dung Hoang ◽  
Thuy Nguyen ◽  
Ngoc Hoanh Dao ◽  
Hien Do Minh ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Carbon Steel ◽  
Root Mean Square ◽  
Flow Rate ◽  
Feed Rate ◽  
Cutting Parameters ◽  
Peanut Oil ◽  
Root Mean Square Roughness ◽  
Depth Of Cut ◽  
Mean Square

This experimental research aimed to build the regression model of grinding S50C carbon steel based on a Regression Optimizer. The workpiece specimens were JIS S50C carbon steel that was hardened at 52HRC. Taguchi L27 orthogonal array was performed with 5 3-levels-factors. The studied factors were combining cutting parameters, such as cutting speed, feed rate, depth of cut, and lubricant parameters, including air coolant flow rate Q and air pressure P. The results show that cutting parameters includes workpiece velocity Vw, feed rate f, and depth of cut t, influence the most on surface roughness Ra, Root Mean Square Roughness Rq, and Mean Roughness Depth Rz,. By contrast, the influence of lubrication parameters is fuzzy. Therefore, this present work focused on predicting and optimizing Ra, Rz, Rq in surface grinding of JSI S50C carbon steel using MQL of peanut oil. In this work, combining of grinding parameters and lubrication parameters were considered as input factors. The regression models of Ra, Rz, and Rq were obtained using Minitab 19 by Regression Optimizer tool, and then the multi-object optimization problem was solved. The present findings have shown that Vietnamese vegetable peanut oil could be considered as the lubricant in the grinding process. The optimum grinding and lubricant parameters as following: the workpiece velocity Vw of 5 m/min, feed rate f of 3mm/stroke, depth of cut of 0.005mm and oil flow rate, air pressure of 91.94 ml/h, 1 MPa, respectively. Corresponding to the surface roughness Ra, Root Mean Square Roughness Rq, and Mean Roughness Depth Rz of 0.6512mm, 4.592mm, 0.8570mm, respectively.  

The Influence of Surface Roughness on Elastohydrodynamic Traction

1987 ◽  
Vol 201 (2) ◽  
pp. 145-150 ◽  
Author(s):  
C R Evans ◽  
K L Johnson
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Rheological Properties ◽  
Root Mean Square ◽  
Contact Pressure ◽  
Viscosity Index ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Sliding Surfaces ◽  
The Mean

If the ratio λ of the nominal elastohydrodynamic film thickness h0 to the root-mean-square roughness is greater than about 5, the traction between two rolling and sliding surfaces is negligibly influenced by surface roughness. The traction is then primarily a function of the parameter α0[Formula: see text], as described in reference (4), where[Formula: see text] is the mean contact pressure and αo is the pressure–viscosity index of the lubricant. When λ lies in the range 0.5–6, it is shown that the effect of asperity interaction is for the traction to still be governed by the bulk rheological properties of the oil, but at a pressure corresponding to the mean contact pressure of the asperities.

Experimental Analysis of Non-Uniform Surface Roughness Affecting to Flow Resistance

2010 ◽  
Author(s):  
A. Matsumoto ◽  
T. Ito ◽  
M. Motozawa ◽  
H. Kawashima ◽  
H. Ando ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Reynolds Number ◽  
Friction Coefficient ◽  
Density Distribution ◽  
Probability Density ◽  
Root Mean Square ◽  
Flow Resistance ◽  
Root Mean Square Roughness ◽  
Probability Density Distribution ◽  
Mean Square

Experimental investigation on non-uniform surface roughness affecting to flow resistance has been carried out. Experiment was performed with the concentric cylinder device. In this experiment, we evaluated non-uniform surface roughness of various surface by the optical method and measured friction coefficient in turbulent flow over each surface roughness. As an evaluation of non-uniform surface roughness, we measured surface roughness profiles of each surface by a laser displacement sensor. Based on this surface roughness profiles, we calculated some roughness parameters such as the root mean square roughness. One important result indicates the relationship between friction coefficient and roughness Reynolds number. The friction coefficient increases logarithmically with increasing roughness Reynolds number. Moreover, to discuss the effect of non-uniform roughness in detail, the Probability Density Function (PDF) of the roughness height and the spectrum of the surface roughness profiles were analyzed. As a result, the frictional drag over the rough surface can be mostly evaluated by the roughness Reynolds number which is defined by the root mean square roughness when the probability density distribution of the surface roughness profile has Gaussian distribution. However, if the probability density distribution does not have Gaussian distribution, kurtosis and skewness of surface roughness profile are also important parameter for the evaluation of the surface roughness.

Autocovariance functions, root-mean-square-roughness height, and autocovariance length for rough deposits of copper, silver, and gold

1982 ◽  
Vol 25 (4) ◽  
pp. 2315-2323 ◽  
Author(s):  
G. Rasigni ◽  
F. Varnier ◽  
M. Rasigni ◽  
J. P. Palmari ◽  
A. Llebaria
Keyword(s):  
Root Mean Square ◽  
Roughness Height ◽  
Root Mean Square Roughness ◽  
Mean Square

The Quantification of Microwear on Chipped Stone Tools: Assessing the Effectiveness of Root Mean Square Roughness (Rq)

2008 ◽  
Vol 33 (2) ◽  
pp. 173-189 ◽  
Author(s):  
W. James Stemp ◽  
Ben E. Childs ◽  
Samuel Vionnet ◽  
Christopher A. Brown
Keyword(s):  
Root Mean Square ◽  
Stone Tools ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Chipped Stone

Direct numerical simulation of turbulence over systematically varied irregular rough surfaces

2019 ◽  
Vol 862 ◽  
pp. 781-815 ◽  
Author(s):  
Y. Kuwata ◽  
Y. Kawaguchi
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Root Mean Square ◽  
Drag Force ◽  
Rough Surfaces ◽  
Skin Friction Coefficient ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Mean Velocity ◽  
Navier Stokes Equation

Lattice Boltzmann direct numerical simulation of turbulent open-channel flows over randomly distributed hemispheres at $Re_{\unicode[STIX]{x1D70F}}=600$ is carried out to reveal the influence of roughness parameters related to a probability density function of rough-surface elevation on turbulence by analysing the spatial and Reynolds- (double-) averaged Navier–Stokes equation. This study specifically concentrates on the influence of the root-mean-square roughness and the skewness, and profiles of turbulence statistics are compared by introducing an effective wall-normal distance defined as a wall-normal integrated plane porosity. The effective distance can completely collapse the total shear stress outside the roughness sublayer, and thus the similarity of the streamwise mean velocity is clearer by introducing the effective distance. In order to examine the influence of the root-mean-square roughness and the skewness on dynamical effects that contribute to an increase in the skin friction coefficient, the triple-integrated double-averaged Navier–Stokes equation is analysed. The main contributors to the skin friction coefficient are found to be turbulence and drag force. The turbulence contribution increases with the root-mean-square roughness and/or the skewness. The drag force contribution, on the other hand, increases in particular with the root-mean-square roughness whereas an increase in the skewness does not increase the drag force contribution because it does not necessarily increase the surface area of the roughness elements. The contribution of the mean velocity dispersion induced by spatial inhomogeneity of the rough surfaces substantially increases with the root-mean-square roughness. A linear correlation is confirmed between the root-mean-square roughness and the equivalent roughness while the equivalent roughness monotonically increases with the skewness. A new correlation function based on the root-mean-square roughness and the skewness is developed with the available experimental and direct numerical simulation data, and it is confirmed that the developed correlation reasonably predicts the equivalent roughness of various types of real rough surfaces.

scholarly journals Manufacture of Highly Transparent and Hazy Cellulose Nanofibril Films via Coating TEMPO-Oxidized Wood Fibers

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 107 ◽  
Author(s):  
Weisheng Yang ◽  
Liang Jiao ◽  
Wei Liu ◽  
Hongqi Dai
Keyword(s):  
Root Mean Square ◽  
Low Cost ◽  
Inorganic Nanoparticles ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Cellulose Nanofibril ◽  
Wood Fibers ◽  
Excellent Thermal Stability ◽  
Blending Method ◽  
Coating Method

Traditionally, inorganic nanoparticles (SiO2, TiO2) have been utilized to tune the optical haze of optoelectronic devices. However, restricted to complex and costly processes for incorporating these nanoparticles, a simple and low-cost approach becomes particularly important. In this work, a simple, effective, and low-cost method was proposed to improve optical haze of transparent cellulose nanofibril films by directly depositing micro-sized 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized wood fibers (“coating” method). The obtained films had a high total transmittance of 85% and a high haze of 62%. The film samples also showed a high tensile strength of 80 MPa and excellent thermal stability. Dual sides of the obtained films had different microstructures: one side was extremely smooth (root-mean-square roughness of 6.25 nm), and the other was extremely rough (root-mean-square roughness of 918 nm). As a reference, micro-sized TEMPO-oxidized wood fibers and cellulose nanofibrils were mixed to form a transparent and hazy film (“blending” method). These results show that hazy transparent films prepared using the “coating” method exhibit superior application performances than films prepared using the “blending” method.

scholarly journals Surface Roughness Estimation in the Orog Nuur Basin (Southern Mongolia) Using Sentinel-1 SAR Time Series and Ground-Based Photogrammetry

2020 ◽  
Vol 12 (19) ◽  
pp. 3200
Author(s):  
Tobias Ullmann ◽  
Georg Stauch
Keyword(s):  
Time Series ◽  
Surface Roughness ◽  
Root Mean Square ◽  
Land Surface ◽  
Arid Environment ◽  
Mean Square ◽  
Geomorphological Mapping ◽  
Multi Temporal ◽  
Dry Conditions ◽  
Single Field

This study demonstrates an application-oriented approach to estimate area-wide surface roughness from Sentinel-1 time series in the semi-arid environment of the Orog Nuur Basin (southern Mongolia) to support recent geomorphological mapping efforts. The relation of selected mono- and multi-temporal SAR features and roughness is investigated by using an empirical multi-model approach and selected 1D and 2D surface roughness indices. These indices were obtained from 48 high-resolution ground-based photogrammetric digital elevation models, which were acquired during a single field campaign. The analysis is backed by a time series analysis, comparing Sentinel-1 features to temporal-corresponding observations and reanalysis datasets on soil moisture conditions, land surface temperature, occurrence of precipitation events, and presence and development of vegetation. Results show that Sentinel-1 features are hardly sensitive to the changing surface conditions over none to sparsely vegetated land, indicating very dry conditions throughout the year. Consequently, surface roughness is the dominating factor altering SAR intensity. The best correlation is found for the combined surface roughness index Z-Value (ratio between the root mean square height and the correlation length) and the mean summer VH intensity with an r2 coefficient of 0.83 and an Root-Mean-Square Error of 0.032.

Morphological Character and Statistical Property of Random Surface of ZnO Thin Film Prepared by RF Magnetron Sputtering

2010 ◽  
Vol 663-665 ◽  
pp. 1159-1162
Author(s):  
Ning Yu Zhang ◽  
Qing Song Huo ◽  
Li Xin Han ◽  
Gang Fu ◽  
Jun Qing Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Root Mean Square ◽  
Gaussian Function ◽  
Gaussian Model ◽  
Film Surface ◽  
Root Mean Square Roughness ◽  
Zno Thin Film ◽  
Mean Square ◽  
Auto Correlation

A method for characterizing the morphology property of ZnO film surface with Gaussian correlation is investigated. The parameters of root-mean-square roughness w and lateral correlation lengthξare introduced in Gaussian model to describe the correlation properties of the random film surfaces. In the experimental performance, ZnO thin films are grown on quartz glass and silicon substrates by the reactive radio-frequency magnetron sputtering method under different deposition pressure. The surface morphologies of the film surface are scanned by an atomic force microscopy. The height auto-correlation functions and root-mean-square roughness are obtained by using the numerical calculus method. Carried on the fitting with the Gaussian function to the height auto-correlation function data, the lateral correlation lengths are extracted to describe the statistical properties of ZnO thin film in mathematics with other parameters.

scholarly journals Damage-Free Photo-Assisted Cryogenic Etching of GaN as Evidenced by Reduction of Yellow Luminescence

1999 ◽  
Vol 4 (S1) ◽  
pp. 914-919 ◽  
Author(s):  
J. T. Hsieh ◽  
J. M. Hwang ◽  
H. L. Hwang ◽  
W. H. Hung
Keyword(s):  
Surface Morphology ◽  
Root Mean Square ◽  
Low Temperatures ◽  
Etch Rate ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Photoluminescence Spectra ◽  
Yellow Luminescence ◽  
Etching Technique ◽  
193 Nm

Damage-free etching of GaN by Cl2, assisted by an ArF (193 nm) excimer laser, is demonstrated. At low temperatures, photo-assisted etching can provide a better etch rate and largely improve the surface morphology and quality. AFM results show that the etched GaN surface is obtained with a root-mean-square roughness of 1.7 nm. As compared with the photoluminescence spectra of photoelectrochemical wet etched GaN, the photo-assisted cryogenic etching is proved to be a damage-free dry etching technique.

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