Discussion and Improvement of the Rectification Capability of NEL Rectifier under the Concentric Reducer Based on FLUENT Simulation

2021 ◽  
Author(s):  
Yuchuan Li ◽  
Chao Dong ◽  
Xin Shao ◽  
Siqi Han ◽  
Tao Wang
Keyword(s):  
Fluent Simulation

scholarly journals Impact of Thermal Dissipation on the Lighting Performance and Useful Life of LED Luminaires Applied to Urban Lighting: A Case Study

2022 ◽  
Vol 19 (2) ◽  
pp. 752
Author(s):  
Juan de Dios Unión-Sánchez ◽  
Manuel Jesús Hermoso-Orzáez ◽  
Manuel Jesús Hervás-Pulido ◽  
Blas Ogáyar-Fernández
Keyword(s):  
Thermal Imaging ◽  
Simulation Software ◽  
Thermal Dissipation ◽  
Junction Temperature ◽  
Ansys Fluent ◽  
Imaging Camera ◽  
Fluent Simulation ◽  
Useful Life

Currently, LED technology is an established form of lighting in our cities and homes. Its lighting performance, durability, energy efficiency and light, together with the economic savings that its use implies, are displacing other classic forms of lighting. However, some problems associated with the durability of the equipment related to the problems of thermal dissipation and high temperature have begun to be detected, which end up affecting their luminous intensity and the useful life. There are many studies that show a direct relationship between the low quality of LED lighting and the aging of the equipment or its overheating, observing the depreciation of the intensity of the light and the visual chromaticity performance that can affect the health of users by altering circadian rhythms. On the other hand, the shortened useful life of the luminaires due to thermal stress has a direct impact on the LCA (Life Cycle Analysis) and its environmental impact, which indirectly affects human health. The purpose of this article is to compare the results previously obtained, at different contour temperatures, by theoretical thermal simulation of the 3D model of LED street lighting luminaires through the ANSYS Fluent simulation software. Contrasting these results with the practical results obtained with a thermal imaging camera, the study shows how the phenomenon of thermal dissipation plays a fundamental role in the lighting performance of LED technology. The parameter studied in this work is junction temperature (Tj), and how it can be used to predict the luminous properties in the design phase of luminaires in order to increase their useful life.

A Study on the Convective Mass Transfer of Nitrogen to Water for a Gas Pressurizing System

2008 ◽  
Author(s):  
Kyoungwoo Seo ◽  
Young-In Kim ◽  
Jae-Kwang Seo ◽  
Doo-Jeong Lee
Keyword(s):  
Mass Transfer ◽  
Boundary Condition ◽  
Natural Convection ◽  
Research Work ◽  
Ideal Gas ◽  
Convective Mass Transfer ◽  
Field Function ◽  
Concentration Difference ◽  
Fluent Simulation ◽  
Fluent 6.3

Mass transfer due to a concentration difference of nitrogen can occur in a nuclear system. Our research work seeks to analyze and understand the mass transfer phenomena of nitrogen in water under the condition of a natural convection using the commercially available CFD computer model, FLUENT 6.3. The maximum solubility was employed to express the boundary condition at an interface between the nitrogen and water. First, the case that nitrogen was transferred to water by only a diffusion was simulated to verify the application of the UDS (User defined scalar) model in FLUENT 6.3 for a mass transfer. Diffusion equation, which was described as a PDE (Partial Differential Equation) with non-homogeneous boundary conditions, was solved and the solved results of the PDE showed a good agreement with those of the FLUENT simulation in the same condition. The same cylinder geometry with that of the diffusion case was used to estimate the convective mass transfer. By the natural convection caused by the thermal boundary condition, the mass transfer of nitrogen had a convection effect. The result of FLUENT 6.3 to compute the convective mass transfer showed that the nitrogen was transferred simultaneously in the entire region by the convection effect and it took about several hours until the mole fraction of nitrogen in the water side reached 50% of the maximum saturated value. The averaged mass transfer coefficient was calculated and compared with the results obtained from the heat and mass transfer analogy. The calculated coefficients showed the lower value than those obtained from the various correlations. When the steam mass transfer toward the gas side was negligible, the pressure drop of the gas side due to the reduced nitrogen caused by a mass transfer was computed using the ideal gas law and the Custom Field Function model in the FLUENT 6.3.

Optimization of Flow and Heat Transfer for a New Double-Layered Microchannel Heat Sink

2019 ◽  
Author(s):  
Huanling Liu ◽  
Bin Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Microchannel Heat Sink ◽  
Transfer Performance ◽  
Temperature Uniformity ◽  
Flow And Heat Transfer ◽  
Fluent Simulation ◽  
New Type ◽  
Improved Design

Abstract In this paper, we propose a new type of DL-MCHS to improve the substrate temperature uniformity of the microchannel heat sink, and conduct the optimization of the New DL-MCHS. The heat transfer and friction characteristics of the novel DL-MCHS are studied by numerical simulation. We compare the heat transfer performance the new DL-MCHS with the traditional TDL-MCHS (the DL-MCHS with truncated top channels λ = 0.38). The results prove the effectiveness of the improved design by FLUENT simulation. When the inlet velocity is kept constant and coolant is water, the heat transfer performance of the New DL-MCHS is higher than that of TDL-MCHS leading to an increase of the temperature uniformity. In order to achieving the best overall heat transfer performance, an optimization of New DL-MCHS is performed by GA (genetic algorithm).

Simulation Analysis and Experimental Research on Complex Structure Processing Technology of Fan Vent

2020 ◽  
Vol 866 ◽  
pp. 82-95
Author(s):  
Guang Yao Li ◽  
Yang Cao ◽  
Tao Yue Yang ◽  
Wen Qing Ma
Keyword(s):  
Simulation Analysis ◽  
Complex Structure ◽  
Processing Parameters ◽  
Simulation Software ◽  
Processing Technology ◽  
Large Temperature ◽  
Coal Consumption ◽  
Ansys Fluent ◽  
Air Supply ◽  
Fluent Simulation

Aiming at the problems of large temperature differences and inconsistent baking speeds at different positions in the tobacco chamber of the tobacco baking room, this paper proposes a complex structure processing technology of fan vent. according to the structure and drying principle of the baking room, ANSYS fluent simulation software was used to analyze the processing parameters of the heat flow field inside the baking room. combining the characteristics of positive and negative air supply baking, the processing and manufacturing parameters of the baking room were optimized, and then the baking comparison test was performed. The results show that: the forward and reverse air-baking method and the complex structure reduces the temperature difference in the interior of the smoke chamber; the forward and reverse air-bake method reduces the baking time by 11 hours, and reduces the coal consumption and power consumption by 12.6%, 48.5%, the standard deviation of temperature monitoring points in the baking room decreased by 44%.

Numerical Simulation of Flow Fluid in Elbow Pipe Based on FLUENT and the Establishment of the Pressure Model

2015 ◽  
Vol 713-715 ◽  
pp. 39-42 ◽  
Author(s):  
Xiao Yang Lu ◽  
Xin Guang Li ◽  
Jin Ming Liu ◽  
Xiao Li Lu ◽  
Hong Liang Zhu ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Theoretical Basis ◽  
Pipe Wall ◽  
Geometric Parameters ◽  
Analysis Method ◽  
Dimensionless Analysis ◽  
Flow Parameters ◽  
Parameter Variations ◽  
Fluent Simulation ◽  
Simulation Results

According to the FLUENT simulation results of the 90°elbow pipe fluid flow condition, the influence of the pressure distribution about the variation of the flow parameters (v、P0 、ρ) and the geometric parameters (R、d、k=R/d、α、β) is analyzed. By using the dimensionless analysis method, on the basis of the influence of the 32 set of parameter variations on the elbow pipe wall pressure distribution regularity, the pressure qualitative function is established including the geometric parameters and the flow parameters. Through the 155 kinds of the FLUENT simulation results, the fitting software 1stOpt is used to verify the internal pressure model above and fit the undetermined coefficients. The verification shows that the model is of a higher calculation precision and the relative error isn’t exceeding 0.003%. It provides a theoretical basis to check the strength of the bend and design the pipeline with high pressure and speed.

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