Local Crater Wear Prediction Using Physics-Based Models

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Jorge A. Olortegui-Yume ◽  
Patrick Y. Kwon
Keyword(s):  
Thermomechanical Properties ◽  
Al2o3 Coating ◽  
Crater Wear ◽  
Al2o3 Layer ◽  
Wear Prediction ◽  
Α Phase ◽  
Pressure Profiles ◽  
Proposed Model ◽  
Temperature And Pressure ◽  
Local Quantity

A physics-based, pointwise model is developed to predict crater profiles of multilayer coated carbides after a series of turning experiments. Dissolution and abrasion mechanisms, which are identified to be the dominant wear mechanisms at the crater, are reformulated into a pointwise or local quantity to predict the crater profiles based on the temperature and pressure profiles from finite element (FE) simulations. The crater profiles predicted by the proposed model have to be adjusted, however, due to the creep deformation of the carbide substrate occurring under the machining conditions employed in our experiment. The crater predictions correlate pretty well with the crater profiles experimentally observed in the multilayer (TiN–Al2O3–TiCN) coated carbides until the wear front reached the middle of the Al2O3 layer. At this point, the Al2O3 coating undergoes the κ-to-α-phase transformation, which makes the wear prediction difficult due to substantial changes in the thermomechanical properties of the Al2O3 coating.

Local Tool Wear Prediction Using Physics-Based Models

2008 ◽  
Author(s):  
Jorge A. Olortegui-Yume ◽  
Kyung-Hee Park ◽  
Patrick Y. Kwon
Keyword(s):  
Tool Wear ◽  
Cutting Tool ◽  
Local Version ◽  
Al2o3 Layer ◽  
Α Phase ◽  
Pressure Profiles ◽  
Tool Wear Prediction ◽  
Temperature And Pressure ◽  
Semi Empirical ◽  
Local Tool

A semi-empirical model based on the physics behind tool wear that can depict the tool wear locally is developed to predict crater profiles of multilayer coated carbides. Dissolution and abrasion relationships are recast into a point-wise or local version to predict directly based on the temperature and pressure profiles from FE simulation. The approach is reasonable to explain the crater profiles observed in multilayer coated carbides. However, the model deviates from the real profiles due to the κ-to-α phase transformation in the middle Al2O3 layer, the change in the friction conditions as each layer is exposed, and the combined wear resistance of multi-layers of the cutting tool.

scholarly journals Simulation of the Residual Stress of the Y2O3/Al2O3 Composite Deuterium Permeation Barrier under Thermal Shock

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Kezhi Huang ◽  
Weijing Wang ◽  
Qinghe Yu ◽  
Lei Hao ◽  
Jing Mi ◽  
...  
Keyword(s):  
Residual Stress ◽  
Thermal Stress ◽  
Thermal Shock ◽  
Principal Stress ◽  
Stress Singularity ◽  
Residual Thermal Stress ◽  
Al2o3 Coating ◽  
Element Analysis ◽  
Al2o3 Layer ◽  
Y2o3 Coating

A deuterium permeation barrier is an essential part in the core component of nuclear reactors. It can protect the structure made of steel from being penetrated by deuterium in a fusion reactor. However, residual stress induced in the operation would dramatically influence the mechanical endurance of the coating, threatening the safety of the facilities. In this paper, finite element analysis was conducted to investigate the residual stress in nanoscale Al2O3 and Y2O3 coatings and their composites under thermal shock, from 700°C to 25°C. The max principal stress is assumed as the cause of crack initiation in the coating, because ceramics are brittle and fragile under tensile stress. Max shear stress and max Mises stress in the systems are also analyzed, and the effect of thickness in the range 100 nm to 1000 nm was investigated. The max principal stress in Al2O3 coating reaches its maximum value, 1.33 GPa, when the thickness of coating reaches 450 nm. And the max principal stress decreases at a very low rate as the thickness increases exceeding 450 nm. The max principal stress in Y2O3 coating increases rapidly as the thickness increases when the thickness of the coating is below 250 nm, and the max principal stress is at about 0.9 GPa when the thickness exceeds 500 nm. The max principal stress in the Y2O3/Al2O3 (150 nm) composite coating occurs in the Al2O3 layer and shows no difference from the single layer of 150 nm thick Al2O3 coating. The max principal stress site of all three kinds of coating is located at the edge of the coating 25 nm away from the interface. The result shows that residual thermal stress in the coating increases as the thickness increases when the thickness of the coating is below 200 nm due to the stress singularity of the interface. And as the thickness exceeds 500 nm, the increase in thickness has little impact on the residual thermal stress in the coating. Coating an Y2O3 top layer will not introduce any more residual thermal stress under the thermal shock condition. The Y2O3 coating causes much less residual stress under thermal shock compared with Al2O3 owing to its much lower Young’s modulus. The max principal stress in the 300 nm thick Y2O3 coating is 0.85 GPa while that of the Al2O3 coating is 1.16 GPa. The max residual stress of the composite Y2O3/Al2O3 (150 nm) coating is determined by the Al2O3 layer.

Numerical Analysis of Flow and Heat Transfer Characteristics on Micro Couette Flow

2014 ◽  
Vol 960-961 ◽  
pp. 551-554
Author(s):  
Lei Huang ◽  
Yang Cui
Keyword(s):  
Shear Stress ◽  
Couette Flow ◽  
Velocity Slip ◽  
Flow And Heat Transfer ◽  
Knudsen Numbers ◽  
Pressure Profiles ◽  
Viscous Heat ◽  
Temperature And Pressure ◽  
In The Beginning ◽  
Stream Direction

In this paper, Couette flow is mainly discussed by studying the general flow behaviour mechanism and importing the velocity slip and temperature jump boundary condition. By analyzing velocity, temperature and pressure profiles at different Knudsen numbers, we concluded that Couette flow is driven by shear stress. The shear stress lies in stream direction. Viscous heat causes the increasing of the fluid’s temperature. With the increasing of Knudsen numbers, the increasing speed increases. It’s in the beginning of transition region that the heat flux has the maximum.

Statistical Characterization of Temperature and Pressure Vertical Profiles for the Analysis of Laser Heterodyne Data

2021 ◽  
Author(s):  
J. Houston Miller ◽  
Monica Flores ◽  
David Bomse
Keyword(s):  
Probability Distributions ◽  
Time Of Day ◽  
George Washington ◽  
Statistical Characterization ◽  
Mixing Ratios ◽  
Line Shapes ◽  
Pressure Profiles ◽  
Historic Data ◽  
Laser Heterodyne ◽  
Temperature And Pressure

<div>We present an analysis of historic pressure and temperature profiles from radiosonde</div><div>launches that will be used in retrieval of mixing fractions for greenhouse gases (GHGs, including</div><div>carbon dioxide, methane, and water vapor) in Laser Heterodyne Radiometry (LHR) data. With</div><div>over 2,700 stations worldwide, the global coverage for weather balloon observations is</div><div>extensive. Radiosonde stations included in the Integrated Global Radiosonde Archive (IGRA),</div><div>are launched simultaneously twice daily at 00:00 and 12:00 UTC. Global stations span all time</div><div>zones in both the Northern and Southern Hemisphere.</div><div> </div><div>Mesa Photonics and George Washington University are developing a variant of LHR</div><div>known as Precision Heterodyne, Oxygen-Corrected Spectroscopy (PHOCS) that simultaneously</div><div>collects high-resolution, oxygen spectral line shape data. Because oxygen concentrations in the</div><div>troposphere and lower stratosphere are constant, these line shapes are uniquely sensitive to both</div><div>temperature and pressure profiles and constrained fitting of these line shapes enables more</div><div>precise GHG concentration retrievals.</div><div> </div><div>Our approach is to collect historic data over several years (typically the prior decade) for</div><div>a particular date window surrounding a PHOCS measurement date for stations across the globe,</div><div>and mine this data for observation probability distributions as a function of level altitude, local</div><div>time of day of launch, latitude, etc. These distributions will then be used as Bayesian priors to</div><div>constrain temperature and pressure fits during the oxygen spectral fitting routine. Subsequently,</div><div>these priors will be used to estimate uncertainties in vertically-resolved GHG mixing ratios.</div>

The diffusivity modeling of different gases in acrylonitrile butadiene styrene (ABS)

2020 ◽  
pp. 089270572097619
Author(s):  
Hamidreza Azimi
Keyword(s):  
Chemical Potential ◽  
Acrylonitrile Butadiene Styrene ◽  
Magnetic Suspension ◽  
Magnetic Suspension Balance ◽  
Proposed Model ◽  
Normal Hexane ◽  
Temperature And Pressure ◽  
Predicted Values ◽  
Different Gases ◽  
Butadiene Styrene

In this work, we used three gases (CO2, N2 and normal hexane) for diffusivity measurements in Acrylonitrile butadiene styrene (ABS). We proposed a diffusion model that the diffusion coefficients of each gas in ABS could be estimated from the specific volume of ABS/gas mixture and chemical potential of gas in ABS. The solubility and diffusivity of three gases into ABS were determined by a magnetic suspension balance. The results showed that the solubility and diffusivity of three gases increased with increasing of pressure. Also it was determined that N2 has a lowest solubility and the highest diffusivity in ABS in all temperature and pressure ranges. It was shown that there was a suitable overlapping between the experimental and predicted values from the proposed model, in which the proposed model could successfully estimate the diffusion coefficient of mentioned gases in ABS in all temperature and pressure ranges.

Design and simulation of a blanket module for TOKAMAK reactors

2019 ◽  
Vol 34 (13) ◽  
pp. 1950103 ◽  
Author(s):  
H. Sadeghi ◽  
M. Habibi
Keyword(s):  
Comsol Multiphysics ◽  
Fusion Reactors ◽  
Tritium Breeding ◽  
Mcnpx Code ◽  
Self Sufficiency ◽  
Proposed Model ◽  
Tokamak Reactors ◽  
Breeding Ratio ◽  
Neutron Multiplier ◽  
Temperature And Pressure

In this paper, we simulated an appropriate model for an advanced breeding blanket of future TOKAMAK fusion reactors with solid breeder (Li4SiO4) building material in the form of pebble beds, ODS ferritic steel as structural material and Beryllium as neutron multiplier. With the MCNPX code, the efficiency of this proposed model for the production and self-sufficiency of tritium was investigated. Total tritium breeding ratio of 1.15 is achieved. The helium-cooled pebble bed system and parameters of temperature and pressure are investigated by COMSOL multiphysics simulating software. The temperature of helium as cooling gas never exceeded 530[Formula: see text]C and the tolerable temperature of beryllium was obtained at 650[Formula: see text]C. In the proposed design, it is adequate to enrich the 6Li to 40%.

scholarly journals Application of Neural Networks for Retrieval of the CO2 Concentration at Aerospace Sensing by IPDA-DIAL lidar

2019 ◽  
Vol 11 (6) ◽  
pp. 659 ◽  
Author(s):  
Gennadii G Matvienko ◽  
and Alexander Ya Sukhanov
Keyword(s):  
Neural Networks ◽  
Co2 Concentration ◽  
Surface Concentration ◽  
Average Concentration ◽  
Differential Absorption ◽  
Near Surface ◽  
Sources And Sinks ◽  
Pressure Profiles ◽  
Temperature And Pressure ◽  
Fully Connected

Greenhouse gas concentrations are increasing over the past few decades, creating the need to measure their concentration with high accuracy, including for determining their trends, sources, and sinks. In this regard, various methods of regional and global control are being developed. One of the measuring methods is passive satellite method, but they allow for you to get data mainly during the day and outside the poles of the Earth. Another method is active lidar; they require the consideration of various aspects that are related to the technical characteristics of the lidar and methods for solving inverse problems. This article discusses the possibility of using lidars for sensing carbon dioxide from space (orbit 450 km) and from a height of 10 km and 23 km, which presumably corresponds to the aircrafts and balloons. As a method of solving the inverse problem, the method of fully connected neural networks with three layers and pre-training of first layer is considered, allowing for the application of additional data, including the IPDA (Integrated Path Differential Absorption) signal, the scattered DIAL (Differential Absorption Lidar) signal, temperature, and pressure profiles. These estimates show the possibility of measuring the average concentration from an orbit height of 450 km with an error of 0.16%, a resolution of 60 km, with a 50 mJ laser pulse energy, and 1 m diameter telescope. It is also shown that it is possible to obtain the concentration profile, including the near-surface concentration with an error of 2 ppm.

The Effects of Oil Supply Pressure at different Groove Position on Temperature and Pressure Profile in Journal Bearing

2013 ◽  
Vol 66 (3) ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
R. S. Dwyer-Joyce ◽  
Aidah Jumahat
Keyword(s):  
Journal Bearing ◽  
Pressure Profile ◽  
Diameter Ratio ◽  
Radial Load ◽  
Oil Supply ◽  
Supply Pressure ◽  
Pressure Profiles ◽  
Hydrodynamic Journal Bearing ◽  
Temperature And Pressure ◽  
Length To Diameter Ratio

The effects of oil supply pressure on the temperature and pressure at different groove locations on a hydrodynamic journal bearing were investigated. A journal with a diameter of 100 mm and a ½ length-to-diameter ratio was used. The supply pressure was set to 0.2, 0.5, and 0.7 MPa at seven different groove locations, namely, -45°, -30°, -15°, 0°, +15°, +30°, and +45°. Temperature and pressure profiles were measured at speed values of 300, 500, and 800 rpm with 10 kN radial load. The results show that the change in oil supply pressure simultaneously reduced the temperature and increased the pressure profile.

Low-cost flow-rate estimate in separate layers along gas wells from temperature and pressure profiles

2013 ◽  
Vol 53 (1) ◽  
pp. 285
Author(s):  
Emile Barrett ◽  
Imran Abbasy ◽  
Chii-Rong Wu ◽  
Zhenjiang You ◽  
Pavel Bedrikovetsky
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Flow Rate ◽  
Low Cost ◽  
Pressure Sensors ◽  
Gas Wells ◽  
Production Rates ◽  
Pressure Profiles ◽  
Temperature And Pressure ◽  
The Mathematical Model

Estimation of rate profile along the well is important information for reservoir characterisation since it allows distinction of the production rates from different layers. The temperature and pressure sensors in a well are small and inexpensive; while flow meters are cumbersome and expensive, and affect the flow in the well. The method presented in this peer-reviewed paper shows its significance in predicting the gas rate from temperature and pressure data. A mathematical model for pressure and temperature distributions along a gas well has been developed. Temperature and pressure profiles from nine well intervals in field A (Cooper Basin, Australia) have been matched with the mathematical model to determine the flow rates from different layers in the well. The presented model considers the variables as functions of thermal properties at each location, which is more accurate and robust than previous methods. The results of tuning the mathematical model to the field data show good agreement with the model prediction. Simple and robust explicit formulae are derived for the effective estimation of flow rate and thermal conductivity in gas wells. The proposed approach has been applied to determine the well gas rate and formation thermal conductivity from the acquired well pressure and temperature data in field A. It allows for recommending well stimulation of layers with low production rates.

Temporal and spatial crater wear prediction of WC/Co tools during dry turning of Ti6Al4V alloy

Wear ◽  
2020 ◽  
Vol 448-449 ◽  
pp. 203229
Author(s):  
Sarvesh Kumar Mishra ◽  
Sudarsan Ghosh ◽  
Sivanandam Aravindan
Keyword(s):  
Ti6al4v Alloy ◽  
Crater Wear ◽  
Wear Prediction ◽  
Dry Turning ◽  
Temporal And Spatial
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