scholarly journals Viscosity modeling for ionic liquid solutions by Eyring-Wilson equation

2012 ◽  
Vol 18 (3) ◽  
pp. 441-447 ◽  
Author(s):  
Yang-Chun He ◽  
Xue-Jiao Xu ◽  
Li-Jun Yang ◽  
Bing Ding
Keyword(s):  
Activity Coefficient ◽  
Simulation Software ◽  
Mathematical Form ◽  
Proposed Model ◽  
Liquid Solutions ◽  
Data Points ◽  
Viscosity Modeling ◽  
Solvent Systems ◽  
Mixture Viscosity ◽  
Ideal Term

A semi-theoretical model based on the classical Eyring?s mixture viscosity equation and the Wilson activity coefficient equation is presented for correlating the viscosity of ionic liquids with solvent systems. The accuracy of the proposed model was verified by comparing calculated and experimental viscosity values from literatures for 49mixtures with total 1560 data points. The results show that the equation similar to the Wilson activity coefficient equation can be well applied to describe the non-ideal term in the Eyring?s mixture viscosity equation. The model has a relatively simple mathematical form and can be easily incorporated into process simulation software.

scholarly journals Improved Modeling of a Multi-Level Inverter for TACS to Reduce Computational Time and Improve Accuracy

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 849
Author(s):  
Sung-An Kim
Keyword(s):  
Mechanical Model ◽  
Simulation Software ◽  
Computational Time ◽  
Electrical Model ◽  
Conventional Model ◽  
Switching Operation ◽  
Air Compressor ◽  
Power Semiconductors ◽  
Proposed Model ◽  
Multi Level

A modeling of a turbo air compressor system (TACS), with a multi-level inverter for driving variable speed, combining an electrical model of an electric motor drive system (EMDS) and a mechanical model of a turbo air compressor, is essential to accurately analyze dynamics characteristics. Compared to the mechanical model, the electrical model has a short sampling time due to the high frequency switching operation of the numerous power semiconductors inside the multi-level inverter. This causes the problem of increased computational time for dynamic characteristics analysis of TACS. To solve this problem, the conventional model of the multi-level inverter has been proposed to simplify the switching operation of the power semiconductors, however it has low accuracy because it does not consider pulse width modulation (PWM) operation. Therefore, this paper proposes an improved modeling of the multi-level inverter for TACS to reduce computational time and improve the accuracy of electrical and mechanical responses. In order to verify the reduced computational time of the proposed model, the conventional model using the simplified model is compared and analyzed using an electronic circuit simulation software PSIM. Then, the improved accuracy of the proposed model is verified by comparison with the experimental results.

An E2GPGP-GASA-Based Multi-Agent Job Shop Scheduling System

2012 ◽  
Vol 505 ◽  
pp. 65-74
Author(s):  
Lin Lin Lu ◽  
Xin Ma ◽  
Ya Xuan Wang
Keyword(s):  
Large Scale ◽  
Job Shop ◽  
Job Shop Scheduling ◽  
Simulation Software ◽  
Prototype System ◽  
Shop Scheduling ◽  
Model Combining ◽  
Proposed Model ◽  
Multi Agent ◽  
Global Planning

In this paper, a job shop scheduling model combining MAS (Multi-Agent System) with GASA (Simulated Annealing-Genetic Algorithm) is presented. The proposed model is based on the E2GPGP (extended extended generalized partial global planning) mechanism and utilizes the advantages of static intelligence algorithms with dynamic MAS. A scheduling process from ‘initialized macro-scheduling’ to ‘repeated micro-scheduling’ is designed for large-scale complex problems to enable to implement an effective and widely applicable prototype system for the job shop scheduling problem (JSSP). Under a set of theoretic strategies in the GPGP which is summarized in detail, E2GPGP is also proposed further. The GPGP-cooperation-mechanism is simulated by using simulation software DECAF for the JSSP. The results show that the proposed model based on the E2GPGP-GASA not only improves the effectiveness, but also reduces the resource cost.

Modeling of a Wind Turbine Rotor Blade System

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Dayuan Ju ◽  
Qiao Sun
Keyword(s):  
Wind Turbine ◽  
Rotor Blade ◽  
Simulation Software ◽  
Wind Flow ◽  
Coupling Effects ◽  
Horizontal Axis Wind Turbine ◽  
Blade Vibration ◽  
Proposed Model ◽  
Blade System ◽  
Coupling Terms

In wind turbine blade modeling, the coupling between rotor rotational motion and blade vibration has not been thoroughly investigated. The inclusion of the coupling terms in the wind turbine dynamics equations helps us understand the phenomenon of rotor oscillation due to blade vibration and possibly diagnose faults. In this study, a dynamics model of a rotor-blade system for a horizontal axis wind turbine (HAWT), which describes the coupling terms between the blade elastic movement and rotor gross rotation, is developed. The model is developed by using Lagrange's approach and the finite-element method has been adopted to discretize the blade. This model captures two-way interactions between aerodynamic wind flow and structural response. On the aerodynamic side, both steady and unsteady wind flow conditions are considered. On the structural side, blades are considered to deflect in both flap and edge directions while the rotor is treated as a rigid body. The proposed model is cross-validated against a model developed in the simulation software fatigue, aerodynamics, structure, and turbulence (fast). The coupling effects are excluded during the comparison since fast does not include these terms. Once verified, we added coupling terms to our model to investigate the effects of blade vibration on rotor movement, which has direct influence on the generator behavior. It is illustrated that the inclusion of coupling effects can increase the sensitivity of blade fault detection methods. The proposed model can be used to investigate the effects of different terms as well as analyze fluid–structure interaction.

Characteristics of activity coefficient models for liquid solutions

AIChE Journal ◽  
2004 ◽  
Vol 50 (4) ◽  
pp. 854-861 ◽  
Author(s):  
Philip T. Eubank ◽  
Xiaonian Wang
Keyword(s):  
Activity Coefficient ◽  
Liquid Solutions ◽  
Activity Coefficient Models

The Simulation Model Establishment of Single Trailing Arm Suspension Vehicle Based on ADAMS

2014 ◽  
Vol 716-717 ◽  
pp. 837-840
Author(s):  
Hui Wang ◽  
Xiao Zhi Wang
Keyword(s):  
Simulation Model ◽  
Simulation Software ◽  
Development Costs ◽  
Development Cycle ◽  
Proposed Model ◽  
Adams Software ◽  
Solid Foundation

Using SGA170 mine car as prototype, this paper establishes simulation model of single trailing arm suspension vehicle steering to trapezoidal mechanism using the ADAMS software, and validates the correctness of the proposed model. It can not only effectively shorten the development cycle, reduce development costs and improve the design precision of products, but also lay a solid foundation for other the simulation software.

Maximum likelihood function for fuzzy count data models (using heaped data as fuzzy)

2020 ◽  
Vol 39 (5) ◽  
pp. 6891-6901
Author(s):  
Godrick Oketch ◽  
Filiz Karaman
Keyword(s):  
Count Data ◽  
Likelihood Function ◽  
Real Data ◽  
Study Data ◽  
Data Models ◽  
Count Data Models ◽  
Proposed Model ◽  
Data Points ◽  
Heaped Data ◽  
Entire Dataset

Count data models are based on definite counts of events as dependent variables. But there are practical situations in which these counts may fail to be specific and are seen as imprecise. In this paper, an assumption that heaped data points are fuzzy is used as a way of identifying counts that are not definite since heaping can result from imprecisely reported counts. Because it is practically unlikely to report all counts in an entire dataset as imprecise, this paper proposes a likelihood function that not only considers both precise and imprecisely reported counts but also incorporates α - cuts of fuzzy numbers with the aim of varying impreciseness of fuzzy reported counts. The proposed model is then illustrated through a smoking cessation study data that attempts to identify factors associated with the number of cigarettes smoked in a month. Through the real data illustration and a simulation study, it is shown that the proposed model performs better in predicting the outcome counts especially when the imprecision of the fuzzy points in a dataset are increased. The results also show that inclusion of α - cuts makes it possible to identify better models, a feature that was not previously possible.

A Modified Nonlinear Hydro Turbine Model

2014 ◽  
Vol 521 ◽  
pp. 200-203
Author(s):  
Li Jie Ding ◽  
Xiao Jun Tang ◽  
Xing Yuan Li
Keyword(s):  
Power System ◽  
Transient Stability ◽  
Hydraulic Turbine ◽  
State Equation ◽  
Simulation Software ◽  
Power System Simulation ◽  
Operation Conditions ◽  
Power Simulation ◽  
Proposed Model ◽  
Turbine Model

The power system simulation software usually use ideal hydraulic turbine model in transient stability simulation. Ideal model is the linearization of turbine steady state equation, it can hardly adapt to the various operation conditions in power system. In this paper, a modified nonlinear model of hydraulic turbine is proposed based on basic hydraulic turbine equations, the model can better reflect the dynamic behavior of the turbine since transient component are taken into account. Field test data verify the validity of the proposed model. The model can greatly improve the accuracy. Furthermore, the model is very simple so that it can be easily used in power simulation software

scholarly journals New model for compressive strength loss of lightweight concrete exposed to elevated temperatures

2019 ◽  
Vol 23 (Suppl. 1) ◽  
pp. 285-293 ◽  
Author(s):  
Ahmet Kurtoglu ◽  
Derya Bakbak
Keyword(s):  
Compressive Strength ◽  
Elevated Temperatures ◽  
Lightweight Concrete ◽  
Strength Loss ◽  
Cooling Regime ◽  
New Model ◽  
Aggregate Content ◽  
Proposed Model ◽  
Data Points ◽  
Temperature Water

This study proposes a new model for the residual compressive strength of structural lightweight concrete after exposure to elevated temperatures up to 1000?C. For this purpose, a database of residual compressive strengths of fire exposed lightweight concrete was compiled from the literature. Database consisted a total number of 289 data points, used for generating training and testing datasets. Symbolic regression was carried out to generate formulations by accounting for various input parameters such as heating rate, cooling regime, target temperature, water content, aggregate type, and aggregate content. Afterwards, predictions of proposed formulation is compared to experimental results. Statistical evaluations verify that the prediction performance of proposed model is quite high.

Simulating Passenger Evacuation in Railway Station under Fire Emergency using Safe Zone Approach

2020 ◽  
Vol 2674 (11) ◽  
pp. 806-812
Author(s):  
Amir Hossein Salarian ◽  
Aida Mashhadizadeh ◽  
Morteza Bagheri
Keyword(s):  
Emergency Evacuation ◽  
Safe Zone ◽  
Simulation Software ◽  
Evacuation Time ◽  
Railway Station ◽  
Railway Stations ◽  
Service Levels ◽  
Proposed Model ◽  
The City ◽  
Safe Zones

Railway stations are usually considered to be one of the main gathering centers of the city; thus, in the event of any incident, there will be significant casualties. The purpose of this study is to simulate strategies for reducing the evacuation time of the railway station in the event of fire using a safe zone approach with simulation software. To reduce the evacuation time, 18 scenarios were introduced and simulated according to (1) number of gates and exit doors, (2) width of the gates, (3) obstacles, (4) priority of the exit doors, and (5) safe zone. The results show that the best evacuation time occurs by increasing the number of exit doors from two to four and considering a safe zone simultaneously; the evacuation time is reduced by 7 min and 19 s. Using safe zones for emergency evacuation has a significant role in reducing evacuation time and improving service levels. Interestingly, the removal of gates and obstacles would increase the evacuation time of passengers. The proposed model could be used for renovating existing railway stations to decrease the consequences of accidents such as fire.

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