scholarly journals Internal Stability Evaluation of Soils

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1439
Author(s):  
Qingfeng Feng ◽  
Hao-Che Ho ◽  
Teng Man ◽  
Jiaming Wen ◽  
Yuxin Jie ◽  
...  
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Numerical Model ◽  
Internal Stability ◽  
Combined Effects ◽  
Stability Evaluation ◽  
Major Threat ◽  
Satisfactory Performance ◽  
Proposed Model ◽  
Simulation Results

Suffusion constitutes a major threat to the foundation of a dam, and the likelihood of suffusion is always determined by the internal stability of soils. It has been verified that internal stability is closely related to the grain size distribution (GSD) of soils. In this study, a numerical model is developed to simulate the suffusion process. The model takes the combined effects of GSD and porosity (n) into account, as well as Wilcock and Crowe’s theory, which is also adopted to quantify the inception and transport of soils. This proposed model is validated with the experimental data and shows satisfactory performance in simulating the process of suffusion. By analyzing the simulation results of the model, the mechanism is disclosed on how soils with specific GSD behaving internally unstable. Moreover, the internal stability of soils can be evaluated through the model. Results show that it is able to distinguish the internal stability of 30 runs out of 36, indicating a 83.33% of accuracy, which is higher than the traditional GSD-based approaches.

scholarly journals Investigation of the Thickness Differential on the Formability of Aluminum Tailor Welded Blanks

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 875
Author(s):  
Jie Wu ◽  
Yuri Hovanski ◽  
Michael Miles
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Model ◽  
Plastic Strain ◽  
Finite Element Model ◽  
Equivalent Plastic Strain ◽  
Element Model ◽  
Dome Height ◽  
Tailor Welded Blanks ◽  
Simulation Results

A finite element model is proposed to investigate the effect of thickness differential on Limiting Dome Height (LDH) testing of aluminum tailor-welded blanks. The numerical model is validated via comparison of the equivalent plastic strain and displacement distribution between the simulation results and the experimental data. The normalized equivalent plastic strain and normalized LDH values are proposed as a means of quantifying the influence of thickness differential for a variety of different ratios. Increasing thickness differential was found to decrease the normalized equivalent plastic strain and normalized LDH values, this providing an evaluation of blank formability.

Wear of a Tool in Double-Disk Lapping of Silicon Wafers

2010 ◽  
Author(s):  
Adam Barylski ◽  
Mariusz Deja
Keyword(s):  
Experimental Data ◽  
Integrated Circuits ◽  
Tool Wear ◽  
Silicon Wafers ◽  
Silicon Ingot ◽  
Proposed Model ◽  
Tool Wear Prediction ◽  
Simulation Results ◽  
High Degree ◽  
Kinematical Parameters

Silicon wafers are the most widely used substrates for fabricating integrated circuits. A sequence of processes is needed to turn a silicon ingot into silicon wafers. One of the processes is flattening by lapping or by grinding to achieve a high degree of flatness and parallelism of the wafer [1, 2, 3]. Lapping can effectively remove or reduce the waviness induced by preceding operations [2, 4]. The main aim of this paper is to compare the simulation results with lapping experimental data obtained from the Polish producer of silicon wafers, the company Cemat Silicon from Warsaw (www.cematsil.com). Proposed model is going to be implemented by this company for the tool wear prediction. Proposed model can be applied for lapping or grinding with single or double-disc lapping kinematics [5, 6, 7]. Geometrical and kinematical relations with the simulations are presented in the work. Generated results for given workpiece diameter and for different kinematical parameters are studied using models programmed in the Matlab environment.

Monte Carlo Simulation of Seebeck Coefficient and Electrical Conductivity in Thermoelectrics

2013 ◽  
Vol 709 ◽  
pp. 176-179 ◽  
Author(s):  
Jian Li
Keyword(s):  
Electrical Conductivity ◽  
Monte Carlo Simulation ◽  
Grain Size ◽  
Monte Carlo ◽  
Seebeck Coefficient ◽  
Ground State ◽  
Proposed Model ◽  
Average Grain Size ◽  
Polycrystalline Ceramics ◽  
Simulation Results

we proposed a scheme for simulating the electronic and thermoelectric properties of polycrystalline ceramics. The simulation results show that the ground state electrons are easily confined in the largest grain. In addition, with the increasing average grain size, the Seebeck coefficient decreases while the electrical conductivity increases monotonically. The simulation results agree well with the available experimental results. Therefore, the proposed model is proved to be a promising approach for thermoelectric investigations.

Prediction of As-Cast Grain Size of Inoculated Multicomponent Aluminum Alloys

2014 ◽  
Vol 790-791 ◽  
pp. 185-190 ◽  
Author(s):  
Qiang Du ◽  
Yan Jun Li
Keyword(s):  
Numerical Simulation ◽  
Grain Size ◽  
Aluminum Alloys ◽  
Cooling Curve ◽  
Restriction Factor ◽  
Grain Sizes ◽  
Cooling Conditions ◽  
Proposed Model ◽  
Simulation Results ◽  
Melt Composition

In this paper, an extendedMaxwell-Hellawell numerical grain size prediction model is employed to predictas-cast grain size of inoculated aluminum alloys. Given melt composition,inoculation and cooling conditions, the model is able to predict maximumnucleation undercooling, cooling curve and final as-cast grain size of multi-componentalloys. The proposed model has been applied to various binary andmulticomponent alloys. Upon analyzing the numerical simulation results, it isfound that for both binary and multi-component alloys, grain size does not havea one-to-one relation with Growth Restriction Factor, Q, but has a clear ubiquitous correlation with the average diffusivity-weightedQ, defined as W in this paper. This founding helps solve the controversy seen inthe recent work on analytical grain size and Q relations. It also has been used to interpret the scatters seenin the measured grain sizes as a function of Q values reported in the literature.

A Simplified Numerical Approach to Characterize the Thermal Response of a Moving Bed Solar Reactor

2021 ◽  
Author(s):  
Assaad Al Sahlani ◽  
Kelvin Randhir ◽  
Nesrin Ozalp ◽  
James Klausner
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Energy Storage ◽  
Solid Particle ◽  
Gas Flow ◽  
Plug Flow ◽  
Fixed Bed ◽  
Flow Rates ◽  
Proposed Model ◽  
Simulation Results

Abstract Concentrated solar thermochemical storage in the form of a zero-emission fuel is a promising option to produce long-duration energy storage. The production of solar fuel can occur within a cylindrical cavity chemical reactor that captures concentrated solar radiation from a solar field. A heat transfer model of a tubular plug-flow reactor is presented. Experimental data from a fixed bed tubular reactor are used for model comparison. The system consists of an externally heated tube with counter-current flowing gas and moving solid particles as the heated media. The proposed model simulates the dynamic behavior of temperature profiles of the tube wall, gas, and particles under various gas flow rates and residence times. The heat transfer between gas-wall, solid particle-wall, gas-solid particle, are numerically studied. The model is compared with experiments using a 4 kW furnace with a 150 mm heating zone surrounding a horizontal alumina tube (reactor) with 50.8 mm OD and a thickness of 3.175 mm. Solid fixed particles of magnesium manganese oxide (MgMn2O4) with the size of 1 mm are packed within the length of 250 mm at the center of the tube length. Simulation results are assessed with respect to fixed bed experimental data for four different gas flow rates, namely 5, 10, 15, 20 standard liters per minute of air, and furnace temperatures in the range of 200 to 1200 °C. The simulation results showed good agreement with maximum steady state error that is less than 6% of those obtained from the experiments among all runs. The proposed model can be implemented as a low-order physical model for the control of temperature inside plug-flow reactors for thermochemical energy storage (TCES) applications.

Grain Refinement in Constrained Groove Pressing of 7050 Aluminum Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 2823-2826 ◽  
Author(s):  
Xiao Lei Dong ◽  
Bing Yun ◽  
Zhi Hao Ma
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Regression Analysis ◽  
Aluminum Alloy ◽  
Grain Refinement ◽  
7050 Aluminum Alloy ◽  
Simulation Results ◽  
Refinement Effect

Constrained groove pressing is a simple and effective method of grain refinement. Using the experimental data obtained by regression analysis, this paper analyzes the simulation of the four pass constrained groove pressing deformation of 7050 aluminum alloy. The simulation results show that the grain size of the billet is refined significantly after four pass constrained groove pressing deformation and decreases from the original 90 μm to a minimum of 14.0 μm. With the increase of the number of deformation passes, refinement effect becomes weakened gradually, the grain size tends to stabilize and the organization is more uniform.

Thermodynamic Modelling of an Adsorption Chiller Based on a Zeolite

2015 ◽  
Author(s):  
Marco Badami ◽  
Armando Portoraro ◽  
Marco Simonetti ◽  
Paolo Tebaldi
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Numerical Model ◽  
Low Temperature ◽  
Low Power ◽  
Thermal System ◽  
Adsorption Chiller ◽  
Solar Cooling ◽  
Simulation Results ◽  
Solar Thermal System

Low power adsorption chillers with low desorption temperatures deserve particular attention, because of the possibility of driving them with a solar thermal system integrated with buildings. The monitoring of a recent solar cooling installation in Turin, Italy, has pointed out the opportunity of developing a dynamic mathematical model, in order to simulate the transient performances of this plant. Focusing on the aforementioned low power-low temperature adsorption chiller category, this work proposes a numerical model of the systems, that include a novel zeolite as the adsorbent and water as the refrigerant fluid. The simulation results have been verified by means of the nominal values of one of the very few commercial chillers of this typology available on the market, and have compared with experimental data found in the literature for similar plants.

Numerical Model of the Temperature Control Curve Linearity of HVAC Module in Automobile Air-Conditioning System and Applications

2010 ◽  
Vol 2 (4) ◽  
Author(s):  
Xiaohua Qu ◽  
Zhaogang Qi ◽  
Junye Shi ◽  
Jiangping Chen ◽  
Hua Zhou
Keyword(s):  
Experimental Data ◽  
Numerical Model ◽  
Temperature Control ◽  
Air Conditioning ◽  
Airflow Rate ◽  
Air Conditioning System ◽  
Control Curve ◽  
Automobile Air Conditioning System ◽  
Simulation Results ◽  
Automobile Air Conditioning

In the present work, a numerical model of the temperature control curve (TCC) linearity of the heating ventilating and air conditioning (HVAC) module in automobile air-conditioning system is established. The numerical model is composed of several higher precision submodels. The simulation results are validated by experimental data performed on a calorimeter test bench. It is found that the simulation data agree with the experimental data very well. The maximum deviations of the airflow rate and the temperature are 3% and 1.4°C, respectively. The factors, which influenced the TCC linearity, are numerically studied. The simulation results show that the different door configuration needs to be matched with the division type for vent ducts of the HVAC module outlet, which can decrease the temperature stratification of airflow at the outlets. Cold and hot air mixing ratio determines the slope of the linearity curve. In addition, the further the distance between the HVAC module outlet and the mixing chamber and the greater the turbulent intensity, the more the cold-hot airflow will fully mix. It contributes to the temperature uniformity at the outlets.

Investigation of Hydroforming Technology for Manufacturing an Auto Complex Part

2019 ◽  
Vol 957 ◽  
pp. 138-147
Author(s):  
Viorel Paunoiu ◽  
Florian Pereira ◽  
Virgil Gabriel Teodor ◽  
Catalina Maier
Keyword(s):  
Experimental Data ◽  
Numerical Model ◽  
Rubber Membrane ◽  
Sheet Hydroforming ◽  
Part Geometry ◽  
Complex Part ◽  
Experimental Tool ◽  
Hydroforming Process ◽  
Simulation Results ◽  
Auto Part

Hydroforming process is used for obtaining different kinds of sheet metal components in an economic manner in terms of time and costs reduction and increase of the product quality. This paper deals with the application of this type of technology for manufacturing a rotational auto part from aluminium alloy. An experimental tool for hydroforming with rubber membrane was used. A set of dies with different geometries has been designed and constructed. Experiments have been conducted for investigation the ability of transferring features from the die onto the blank surface for different die geometries and pressures. The hydroformed part was measured using CMM. Based on the experimental data a numerical model was designed. FEM using Abaqus solver was used for investigated the part geometry and the effective stress distribution under various pressures conditions and dies geometries. The experimental and simulation results show the feasibility of applying the sheet hydroforming process in order to obtain a sound product.

scholarly journals Modeling the effect of the stress demagnetization phenomenon on the magnetic properties in a no Fe-Si 3% sheet

2015 ◽  
Vol 12 (2) ◽  
pp. 237-252 ◽  
Author(s):  
Malika Yakhlef ◽  
Sebti Boukhtache ◽  
Mabrouk Chabane
Keyword(s):  
Magnetic Properties ◽  
Eddy Current ◽  
Mechanical Model ◽  
Magnetic Hysteresis ◽  
Demagnetization Factor ◽  
Satisfactory Performance ◽  
Proposed Model ◽  
External Stresses ◽  
Simulation Results ◽  
Magnetostrictive Behavior

The aim of this paper is the modeling of the stress demagnetization effect on the magnetic properties in a non-oriented Fe-Si 3% sheet under different external stresses. The magneto-mechanical model used for magnetic hysteresis is based on a model originally formulated by Sablik-Jiles-Atherthon (S.J.A.). This latter has been modified by including both the stress demagnetization factor and the eddy current effects. The influence of the stress demagnetization term SDT on the magnetostrictive behavior of the material is also modeled. The proposed model has been validated by extensive simulations at different stresses, namely compressive and tensile stresses. Simulation results obtained by this model are very close to those published in the literature. Using the proposed model, very satisfactory performance has been achieved.

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