Design and Simulation of Internal Flowing Twisted Conduits for Cooling of Lithium-Ion Batteries through Thermal Characterization

Lithium-ion batteries are extensively used for electric vehicles, owing to their great power and energy density. A battery thermal management system is essential for lithium-ion batteries. With the extensive utilization of liquid-cooling approaches for lithium-ion batteries’ thermal management, temperature homogeneity is considerably influenced by coolant distribution. A lower temperature of the cooling fluid brings about a lower temperature of the cell, but the relation and the amount are important to be analyzed. The cooling efficiency is considerably influenced by the flowing conduit arrangement in the cooling plate. Different parameters are affected by the cooling performance of the battery pack. Consequently, the effect of entrance temperature of coolant fluid, current rate, environment temperature, entrance velocity of the coolant fluid, and plate material on the performance and efficiency of a battery thermal management system were investigated. In this investigation, the program ANSYS/FLUENT was employed as the numerical solver to solve the problem. The simulation was accomplished after the end of the discharge. It was seen that the temperature distributions were the most sensitive to the entrance velocity of coolant fluid. It was concluded that the entrance velocity of coolant fluid has the greatest impact on the cooling efficiency and performance of the cold plate.

Analytical Solution of Water Vapor Condensation in Flow Channel of Battery Pack

The analytical solutions for condensation (and evaporation) rates of laminar humid air flow in the channels of a battery pack at both entrance and downstream regions are obtained/modeled. The effects of the entrance fluid velocity profile and the aspect ratio of the flow channel are taken into consideration. Initially, an analytical solution for laminar humid air flows' condensation at the flow channel with infinite aspect ratio and fully developed flow profile at the entrance is obtained. The solution is in good agreement with the simulation result obtained from a correlated fluent condensation model. After performing simulations of water vapor condensation and evaporation in the flow channel for different aspect ratios and entrance velocity profiles, the analytical solutions of condensation and evaporation rate of water vapor are presented in analytic forms by adding appropriate coefficients/correction factors to the solution for the flow in the channel with infinite aspect ratio. The resulting model accurately captures the effects of the entrance velocity profile and aspect ratio.

Flow Analysis through Collector Well Laterals: A Case Study from Sonoma County Water Agency, California

The Sonoma County Water Agency (SWCA) uses six radial collector wells along the Russian River west of Santa Rosa, to provide water for several municipalities and water districts in north-western California. Three collector wells (1, 2, and 6) are located in the Wohler area, and three collector wells (3, 4, and 5) are located in the Mirabel area. The objective of this paper is to highlight the performance of the three collector wells located in the Mirabel area since their construction. The 2015 investigation showed a lower performance of Collectors 3 and 4 compared to their original performances after construction in 1975, while the performance of Collector 5 was relatively stable since 1982. The potential change in capacity could be due to the increase in encrustation observed during the visual inspection of laterals in all three collector wells. Overall, the three collectors are still within the optimal design parameters (screen entrance velocity < 0.305 m min−1 and axial flow velocity of lateral screens < 1.524 m s−1).

Analysis and Calculation of the Fluid Flow and the Temperature Field by Finite Element Modeling

This paper presents a fundamental and accurate approach to study numerical analysis of fluid flow and heat transfer inside a channel. In this study, the Finite Element Method is used to analyze the channel, which is divided into small subsections. The small subsections are discretized using higher number of domain elements and the corresponding number of nodes. MATLAB codes are developed to be used in the analysis. Simulation results showed that the analyses of fluid flow and temperature are influenced significantly by the changing entrance velocity. Also, there is an apparent effect on the temperature fields due to the presence of an energy source in the middle of the domain. In this paper, the characteristics of flow analysis and heat analysis in a channel have been investigated.

Effect Of Sparging In Microalgae (Dunaliella Tertiolecta) Cuture Using Bubble Column

Microalgae as a photosynthetic microorganism that contain chlorophyll has high potential to produce novel high value compounds that can be used in food, pharmaceutical and cosmetic industries. With lack of rigid cell wall, microalgae susceptible to have hydrodynamic stress by increasing aeration rate. Increasing gas flow rate will increase the productivity to optimum condition, but after this condition the productivity will decrease due to cell disruption. In this research has been focused on effect of sparging on microalgae cell damage. Sparging experiment was carried out by varying gas flow rate between 0.59 to 5.13 L.min-1 with a sparger made from needle inserted to a piece of silicon. The needle was used with diameter 0.4 to 1.2 mm and 1-9 needles. With this variables resulted gas entrance velocity between 2.56-104 m.s-1. The cell death rate constant (kd) was calculated by loss of cell viability in time using Coulter counter and Flowcytometer. From the experiments resulted gas entrance velocity was main cause for cell damagae. The small bubble was more detrimental than bigger size of bubble. Bubble rising as like in animal cell culture was no effect to detrimental cell.Keywords : D. tertiolecta, cell death rate constant, gas entrance velocity

Numerical Simulation of Oblique Towing Tests and Rotating Arm Tests for a Submarine Model in Same Grid Topology

The numerical simulation of oblique towing tests (OTT) and rotating arm tests (RAT) for a submarine model was undertaken with the same grid topology. As for the OTT simulation, to improve the efficiency and accuracy of the computation, the drift sweep procedure was adopted. In contrast with the steady drift case, rotating motion for a submarine is more complex. The rotating reference frame was adopted to deal with the rotation problem. The Coriolis force and centrifugal force due to the computation in a body-fixed rotating coordinate system were treated explicitly and added to the momentum equations as source terms. The user-defined boundary conditions were coded to give the correct magnitude and direction of entrance velocity. Lastly, the computed forces and moments as a function of drift angle during the two kinds of simulations were compared with experimental results, as well as literature values. They always show the correct trend. The flow field and streamline patterns in rotating motion were depicted. It indicates that the method used in the paper is reliable and the same grid topology can be used for the simulation of two simplified maneuvers.

Study on the Performance of Water Lubricated Stern Tube Bearing Based on Fluent

Apply FLUENT software to establish the water lubricated rubber stern tube bearing CFD model,study temperature and pressure distribution of the bearings at different speeds of rotation. It plays an important role in improving the performance of ship water lubricated stern tube bearing and security, reliability of propulsion system. The simulation results show that increasing the shaft speed in a certain range can reduce water film temperature, the effect is obvious especially at slow entrance velocity of bearings. Both high and low pressure ranges in the middle of bearings are enlarged with the increase of speed.

The Simulation Analysis of Tunnel Wind Cooling System in Shenyang Area

Applied FLUENT simulation software to research the influence of tunnel length, tunnel entrance velocity, tunnel equivalent diameter and tunnel buried depth four important factors on the tunnel wind cooling system in Shenyang area. The results show that, with the increase of tunnel length and tunnel buried depth and with the decrease of tunnel entrance velocity and tunnel equivalent diameter, the outdoor air which passed into the tunnel cooling amplitude increases. For the tunnel wind cooling system optimization design in Shenyang area and the surrounding areas, the advices are that tunnel buried depth should not be more than 6m and tunnel entrance velocity should not be more than 5m/s.