Vol.15, No.4, 2019-Table of Contents
  • Optimization of the Heat Dissipation Structure and Temperature Distribution in an Electric Vehicle Power Battery
  • Abstract In order to ensure that the lithium-ion battery pack keeps good working performance during the driving of electric vehicle, the heat generation mechanism and heat transfer characteristics of lithium-ion battery are analyzed. The power battery pack of electric vehicle is simulated by advanced vehicle simulator. The simulation results of battery pack current under typical cycle conditions and the heat source curve of lithium ion battery are obtained, which provide data for the simulation of heat source input of battery temperature field. On this basis, the flow field and temperature fiel d of the original lithium-ion battery pack of electric vehicle… More
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  • A Control Algorithm for the Optimization of Batch Reactor-Based Processes
  • Abstract Levenberg-Marquardt (LM) algorithm is applied for the optimization of the heat transfer of a batch reactor. The validity of the approach is verified through comparison with experimental results. It is found that the mathematical model can properly describe the heat transfer relationships characterizing the considered system, with the error being kept within ±2°C. Indeed, the difference between the actual measured values and the model calculated value curve is within ±1.5°C, which is in agreement with the model assumptions and demonstrates the reliability and effectiveness of the algorithm applied to the batch reactor heat transfer model. Therefore, the present work provides… More
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  • Investigation of the Mechanism of Grout Penetration in Intersected Fractures
  • Abstract To study the penetration mechanism of cement-based slurry in intersected fractures during grouting and the related pressure distribution, we have used two different variants of cement, namely, basic cement slurry and fast-setting cement slurry. The influence of a retarder, time-varying viscosity, fracture width and location of injection hole is also considered. A finite element software is used to implement two and three-dimensional numerical models for grouting of intersected fractures in hydrostatic conditions. Results show that there are significant differences in the diffusion morphology and pressure distribution depending on the considered cement slurry. Retarder can effectively slow down the rising rate… More
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  • A Numerical Investigation of the Thermal Performances of an Array of Heat Pipes for Battery Thermal Management
  • Abstract A comparative numerical study has been conducted on the thermal performance of a heat pipe cooling system considering several influential factors such as the coolant flow rate, the coolant inlet temperature, and the input power. A comparison between numerical data and results available in the literature has demonstrated that our numerical procedure could successfully predict the heat transfer performance of the considered heat pipe cooling system for a battery. Specific indicators such as temperature, heat flux, and pressure loss were extracted to describe the characteristics of such a system. On the basis of the distributions of the temperature ratio of… More
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  • On the Application of a Mobile Grid Technology to Computational Fluid Dynamics
  • Abstract On the basis of harmonic mapping theory, a mobile grid technology is applied to computational fluid dynamics (CFD). Starting from the observation that standard fixed-grid techniques often fail in addressing problems with large deformations, we elaborate a new algorithm relying on the software COMSOL Multiphysics 5.3a to solve the coupling of the mobile grid equation and the governing differential equations for fluid flow. The motion of water in a water tank when the tank waggles is simulated. We demonstrate that this technology can be implemented without a significant increase in the computational cost with respect to standard numerical methods More
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  • Simulation of Heat and Mass Transfer in a Grain Pile on the Basis of a 2D Irregular Pore Network
  • Abstract The so-called pore network model has great advantages in describing the process of heat and mass transfer in porous media. In order to construct a random two-dimensional (2D) irregular pore network model for an unconsolidated material, image processing technology was used to extract the required topological and geometric information from a 2D sample of soybean particles, and a dedicated algorithm was elaborated to merge some adjacent small pores. Based on the extracted information, a 2D pore network model including particle information was reconstructed and verified to reflect the pore structure of discrete particles. This method was used to reconstruct a… More
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  • Influence of the Hole Chamfer on the Characteristics of a Multi-hole Orifice Flowmeter
  • Abstract In order to analyze the influence of the hole chamfer on the metering performances of a Multi-hole Orifice Flowmeter and optimize the related orifice structure, a multi-hole orifice flowmeter with DN80 and throttle ratio of 0.45 was considered in the present study. The flow field characteristics were determined in the framework of a CFD technique. The results show that the multi-hole orifice flowmeter with filleting transition around the throttle orifice has higher accuracy in a wide range of the space of parameters, and is more suitable for accurate measurement of fluid in process control. More
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  • Experimental and Theoretical Analysis of the Drag Torque in Wet Clutches
  • Abstract Traditional mathematical models cannot predict and explain the phenomenon by which the drag torque (DT) in wet clutches rises in the high-speed zone. In order to evaluate the DT in such conditions, a two-phase air-fluid mathematical model for a DT with grooves was elaborated. The mathematical model was based on the theory of viscous fluid flow. A two-phase volume of fluid model was also used to investigate the distribution and volume fraction of air and fluid. Experiments on three friction plates with different grooves were conducted to validate the resulting mathematical model. It was found that the gap between plates… More
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  • Water Flow Characteristics and Related Effects in PEMFC
  • Abstract Water management in proton exchange membrane fuel cells (PEMFC) is a topic of great importance for the optimization of these systems. Effective proton conductivity calls for moderate moisture content in the membrane, while uneven water distribution can lead to instability of the whole flow field, thereby decreasing the performance of the fuel cell. In the present study, a simplified two-tier hybrid structure is used to investigate the impact of the dynamic behavior of liquid water on the current density of the PEMFC. Simulation results show that water droplets attached to wall sides tend to increase current density. Visualization experiments confirm… More
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  • An Experimental Study on Fuel Combustion Under External Irradiance
  • Abstract In order to investigate the burning characteristics of a 0# diesel and 3# jet fuel, a small-scale experimental bench mainly composed of a cone calorimeter was arranged. The heat release and burning rates were investigated changing the external irradiance in order to clarify the triadic relationship among these quantities. The effective heat of combustion of 0# diesel and 3# jet fuel were 38.89 MJ/kg and 43.15 MJ/kg, respectively, with the corresponding combustion efficiencies being 96.78% and 99.60% (the effective peak heat of combustion being 1.665 times the mean value for both types of fuel). According to our experimental results, the… More
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