An Analytical Model for Dynamic Pull-In of Electrostatic Perforated Plate Actuators

2014 ◽  
Vol 614 ◽  
pp. 160-163
Author(s):  
Yu Ming Fang ◽  
Jia Jia Yu ◽  
Wen Wen Fu ◽  
De Bo Wang ◽  
Pu Li
Keyword(s):  
Analytical Model ◽  
Perforated Plate ◽  
Electrostatic Actuators ◽  
Approximate Models ◽  
Fringing Field ◽  
Capacitance Model ◽  
Simulation Results ◽  
Fringe Effect ◽  
Good Agreement

Pull-in parameters are important parameters of electrostatic actuators. This paper presents three analytical approximate models for calculating the dynamic pull-in voltage and pull-in position of a perforated plate, respectively. The effects of the fringing field are included in two models. The accuracy of the three present models is compared with ANSYS results. Simulation results show that the detailed capacitance model with fringe effect has good agreement with the FEM results.

A Model for the Pull-In Parameters of Magnetostatic Actuators with Fringing Effect

2013 ◽  
Vol 432 ◽  
pp. 229-234
Author(s):  
Yu Ming Fang ◽  
Jun Jian Qie
Keyword(s):  
Analytical Model ◽  
Simple Analytical Model ◽  
The Past ◽  
Wide Range ◽  
Mems Actuators ◽  
Fringing Field ◽  
Simulation Results ◽  
Fringing Field Effect ◽  
Gap Spacing ◽  
Good Agreement

Predicting Pull-In parameters is crucial in the design of MEMS actuators. In the past, the Pull-In parameters of magnetostatic actuators with the fringing field effect are often estimated using finite element method (FEM). However, FEM is cumbersome, time consuming and non-transparent, which is not convenient for the design optimization. Usually, there are a simple analytical model without leakage reluctance and a detailed analytical model with leakage reluctance respectively. This paper used the two models to derive the Pull-In model of magnetostatic actuators respectively. The accuracy of the two Pull-In models is examined by comparing their results with the FEM results. Simulation results show that the Pull-In model without leakage reluctance is unsuitable to predict Pull-In parameters. The Pull-In model with leakage reluctance has shown a good agreement with the FEM results for a wide range of gap spacing.

scholarly journals Temperature dependent analytical model for submicron GaAs-MESFET

2021 ◽  
Vol 10 (3) ◽  
pp. 1271-1282
Author(s):  
Mohamed Djouder ◽  
Arezki Benfdila ◽  
Ahcene Lakhlef
Keyword(s):  
Analytical Model ◽  
Temperature Dependent ◽  
Gaas Mesfet ◽  
Voltage Variation ◽  
Proposed Model ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Simulation Results ◽  
Parameter Values ◽  
Good Agreement

MESFET are used in circuitsof gigahertz frequencies as they are based on gallium arsenide (GaAs) having electron mobility six times higher than that of silicon. An analytical model simulating different device current-voltage characteristics, i.e., output conductance and output transconductance of a 0.3μm gate MESFET with temperature dependence is proposed. The model is validated by comparing the results of the proposed model and those of the numerical simulation. The parameter values are computed using an intrinsic MESFET of two-dimensional geometry. In this work, the distribution of different output loads for varied applied voltages is considered. Simulation results obtainedunder temperature variation effectsfor load distribution and applied driven voltage variation are considered. The RMS and average errors between the different models and GaAs MESFET simulations are calculated to evidence the proposed model accuracy. This was demonstrated by a good agreement between the proposed model and the simulation results, which are found in good agreement. The simulation results obtained under temperature variations were discussed and found to complement those obtained in the literature. This clarifies the relevance of the suggested model analytical.

scholarly journals Measuring Hydrometeors Using a Precipitation Microphysical Characteristics Sensor: Sampling Effect of Different Bin Sizes on Drop Size Distribution Parameters

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Xichuan Liu ◽  
Taichang Gao ◽  
Yuntao Hu ◽  
Xiaojian Shu
Keyword(s):  
Drop Size ◽  
Rain Rate ◽  
Monte Carlo Model ◽  
Rain Gauge ◽  
Sampling Schemes ◽  
Distribution Parameters ◽  
Optimum Sampling ◽  
Simulation Results ◽  
The Impact ◽  
Good Agreement

In order to improve the measurement of precipitation microphysical characteristics sensor (PMCS), the sampling process of raindrops by PMCS based on a particle-by-particle Monte-Carlo model was simulated to discuss the effect of different bin sizes on DSD measurement, and the optimum sampling bin sizes for PMCS were proposed based on the simulation results. The simulation results of five sampling schemes of bin sizes in four rain-rate categories show that the raw capture DSD has a significant fluctuation variation influenced by the capture probability, whereas the appropriate sampling bin size and width can reduce the impact of variation of raindrop number on DSD shape. A field measurement of a PMCS, an OTT PARSIVEL disdrometer, and a tipping bucket rain Gauge shows that the rain-rate and rainfall accumulations have good consistencies between PMCS, OTT, and Gauge; the DSD obtained by PMCS and OTT has a good agreement; the probability of N0, μ, and Λ shows that there is a good agreement between the Gamma parameters of PMCS and OTT; the fitted μ-Λ and Z-R relationship measured by PMCS is close to that measured by OTT, which validates the performance of PMCS on rain-rate, rainfall accumulation, and DSD related parameters.

scholarly journals Cheating at Craps

2021 ◽  
Vol 48 (4) ◽  
pp. 53-61
Author(s):  
Andrea Marin ◽  
Carey Williamson
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Modeling And Simulation ◽  
Analytical Model ◽  
Quantitative Evaluation ◽  
Mathematical Analysis ◽  
Simulation Modeling ◽  
Analytical Modeling ◽  
The World ◽  
Simulation Results

Craps is a simple dice game that is popular in casinos around the world. While the rules for Craps, and its mathematical analysis, are reasonably straightforward, this paper instead focuses on the best ways to cheat at Craps, by using loaded (biased) dice. We use both analytical modeling and simulation modeling to study this intriguing dice game. Our modeling results show that biasing a die away from the value 1 or towards the value 5 lead to the best (and least detectable) cheating strategies, and that modest bias on two loaded dice can increase the winning probability above 50%. Our Monte Carlo simulation results provide validation for our analytical model, and also facilitate the quantitative evaluation of other scenarios, such as heterogeneous or correlated dice.

scholarly journals Simulation and Experimental Study on Wear of U-Shaped Rings of Power Connection Fittings under Strong Wind Environment

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 735
Author(s):  
Songchen Wang ◽  
Xianchen Yang ◽  
Xinmei Li ◽  
Cheng Chai ◽  
Gen Wang ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
Adhesive Wear ◽  
Surface Hardness ◽  
Wear Depth ◽  
Strong Wind ◽  
Wear Model ◽  
Wind Environment ◽  
Simulation Results ◽  
Oxidation Wear ◽  
Good Agreement

The objective of this study was to investigate the wear characteristics of the U-shaped rings of power connection fittings, and to construct a wear failure prediction model of U-shaped rings in strong wind environments. First, the wear evolution and failure mechanism of U-shaped rings with different wear loads were studied by using a swinging wear tester. Then, based on the Archard wear model, the U-shaped ring wear was dynamically simulated in ABAQUS, via the Umeshmotion subroutine. The results indicated that the wear load has an important effect on the wear of the U-shaped ring. As the wear load increases, the surface hardness decreases, while plastic deformation layers increase. Furthermore, the wear mechanism transforms from adhesive wear, slight abrasive wear, and slight oxidation wear, to serious adhesive wear, abrasive wear, and oxidation wear with the increase of wear load. As plastic flow progresses, the dislocation density in ferrite increases, leading to dislocation plugs and cementite fractures. The simulation results of wear depth were in good agreement with the test value of, with an error of 1.56%.

TCAD Study of the Raised SiGe Source/Drain in 40nm PMOS

2015 ◽  
Vol 645-646 ◽  
pp. 70-74 ◽  
Author(s):  
Min Zhong ◽  
Yu Hang Zhao ◽  
Shou Mian Chen ◽  
Ming Li ◽  
Shao Hai Zeng ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Critical Role ◽  
Sige Layer ◽  
Strain Engineering ◽  
Effect Transistor ◽  
Simulation Results ◽  
Aided Design ◽  
The Relationship ◽  
Growth Experiments ◽  
Good Agreement

An embedded SiGe layer was applied in the source/drain areas (S/D) of a field-effect transistor to boost the performance in the p channels. Raised SiGe S/D plays a critical role in strain engineering. In this study, the relationship between the SiGe overfilling and the enhancement of channel stress was investigated. Systematic technology computer aided design (TCAD) simulations of the SiGe overfill height in a 40 nm PMOS were performed. The simulation results indicate that a moderate SiGe overfilling induces the highest stress in the channel. Corresponding epitaxial growth experiments were done and the obtained experimental data was in good agreement with the simulation results. The effect of the SiGe overfilling is briefly discussed. The results and conclusions presented within this paper might serve as useful references for the optimization of the embedded SiGe stressor for 40 nm logic technology node and beyond.

Numerical Simulation on Thixo-Forging of Magnesium Matrix Composite

2011 ◽  
Vol 189-193 ◽  
pp. 2535-2538 ◽  
Author(s):  
Hong Yan ◽  
Wen Xian Huang
Keyword(s):  
Numerical Simulation ◽  
Matrix Composite ◽  
Metal Flow ◽  
Magnesium Matrix Composite ◽  
Magnesium Matrix ◽  
Simulation Based ◽  
Prior Literature ◽  
Simulation Results ◽  
Computer Numerical Simulation ◽  
Good Agreement

The thixo-forging of magnesium matrix composite was analyzed with computer numerical simulation based on rigid viscoplastic finite element method. The constitutive model of SiCp/AZ61 composite was established in our prior literature. Behavior of metal flow and temperature field were obtained. The differences between traditional forging and thixo-forging processes were analyzed. Results indicated that thixo-forging was better in filling cavity than forging. Simulation results were good agreement with experimental ones.

The penetration and ricochet of ogive-nosed rigid projectiles obliquely impacting metallic targets

2021 ◽  
pp. 204141962110377
Author(s):  
Yaniv Vayig ◽  
Zvi Rosenberg
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Dynamic Pressure ◽  
Oblique Impacts ◽  
Simulation Results ◽  
The Impact ◽  
Penetration Depths ◽  
Resistance To Penetration ◽  
Good Agreement

A large number of 3D numerical simulations were performed in order to follow the trajectory changes of rigid CRH3 ogive-nosed projectiles, impacting semi-infinite metallic targets at various obliquities. These trajectory changes are shown to be related to the threshold ricochet angles of the projectile/target pairs. These threshold angles are the impact obliquities where the projectiles end up moving in a path parallel to the target’s face. They were found to depend on a non-dimensional entity which is equal to the ratio between the target’s resistance to penetration and the dynamic pressure exerted by the projectile upon impact. Good agreement was obtained by comparing simulation results for these trajectory changes with experimental data from several published works. In addition, numerically-based relations were derived for the penetration depths of these ogive-nosed projectiles at oblique impacts, which are shown to agree with the simulation results.

Aerodynamic Similarity Principles and Scaling Laws for Windmilling Fans

2018 ◽  
Author(s):  
Dilip Prasad
Keyword(s):  
Rotational Speed ◽  
Pressure Loss ◽  
Scaling Laws ◽  
Dynamic Pressure ◽  
Stagnation Pressure ◽  
Design Parameters ◽  
Similarity Parameter ◽  
Wide Range ◽  
Simulation Results ◽  
Good Agreement

Windmilling requirements for aircraft engines often define propulsion and airframe design parameters. The present study is focused is on two key quantities of interest during windmill operation: fan rotational speed and stage losses. A model for the rotor exit flow is developed, that serves to bring out a similarity parameter for the fan rotational speed. Furthermore, the model shows that the spanwise flow profiles are independent of the throughflow, being determined solely by the configuration geometry. Interrogation of previous numerical simulations verifies the self-similar nature of the flow. The analysis also demonstrates that the vane inlet dynamic pressure is the appropriate scale for the stagnation pressure loss across the rotor and splitter. Examination of the simulation results for the stator reveals that the flow blockage resulting from the severely negative incidence that occurs at windmill remains constant across a wide range of mass flow rates. For a given throughflow rate, the velocity scale is then shown to be that associated with the unblocked vane exit area, leading naturally to the definition of a dynamic pressure scale for the stator stagnation pressure loss. The proposed scaling procedures for the component losses are applied to the flow configuration of Prasad and Lord (2010). Comparison of simulation results for the rotor-splitter and stator losses determined using these procedures indicates very good agreement. Analogous to the loss scaling, a procedure based on the fan speed similarity parameter is developed to determine the windmill rotational speed and is also found to be in good agreement with engine data. Thus, despite their simplicity, the methods developed here possess sufficient fidelity to be employed in design prediction models for aircraft propulsion systems.

Grey Logistic Model to Predict the Effective Irrigation Area in Liaoning Province

2014 ◽  
Vol 641-642 ◽  
pp. 179-182 ◽  
Author(s):  
Jin Liang Chen
Keyword(s):  
Logistic Model ◽  
Structural Adjustment ◽  
Logistic Equation ◽  
Liaoning Province ◽  
Forecasting Model ◽  
Irrigation Area ◽  
Agricultural Resources ◽  
Upper Limit ◽  
Simulation Results ◽  
Good Agreement

Through grey estimation of the parameters of logistic equation, a grey logistic forecasting model is established. The effective irrigation area in Liaoning Province was simulated by the model. The simulation results had good agreement with the available data, with a correlation of 0.95. The effective irrigation area was predicted to be 1.583 million hectares in 2018, very close to the predicted upper limit of 1.588 million hectares. Thus, there is little potential for the development of the effective irrigation area, rendering the structural adjustment of agricultural resources very necessary.

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