scholarly journals Optimal thermal sensors placement based on indoor thermal environment characterization by using CFD model

2021 ◽  
Vol 19 (3) ◽  
pp. 628-641
Author(s):  
F Faridah ◽  
Sentagi Utami ◽  
Ressy Yanti ◽  
S Sunarno ◽  
Emilya Nurjani ◽  
...  
Keyword(s):  
Euclidean Distance ◽  
Cfd Simulation ◽  
Thermal Environment ◽  
Thermal Characteristics ◽  
Data Sets ◽  
Cfd Model ◽  
Outdoor Climate ◽  
Computational Fluid Dynamics Cfd ◽  
Maximum Root ◽  
Optimum Sensor

This paper discusses an analysis to obtain the optimal thermal sensor placement based on indoor thermal characteristics. The method relies on the Computational Fluid Dynamics (CFD) simulation by manipulating the outdoor climate and indoor air conditioning (AC) system. First, the alternative sensor's position is considered the optimum installation and the occupant's safety. Utilizing the Standardized Euclidean Distance (SED) analysis, these positions are then selected for the best position using the distribution of the thermal parameters' values data at the activity zones. Onsite measurement validated the CFD model results with the maximum root means square error, RMSE, between both data sets as 0.8°C for temperature, the relative humidity of 3.5%, and an air velocity of 0.08m/s, due to the significant effect of the building location. The Standardized Euclidean Distance (SED) analysis results are the optimum sensor positions that accurately, consistently, and have the optimum % coverage representing the thermal condition at 1,1m floor level. At the optimal positions, actual sensors are installed and proven to be valid results since sensors could detect thermal variables at the height of 1.1m with SED validation values of 2.5±0.3, 2.2±0.6, 2.0±1.1, for R15, R33, and R40, respectively.

Verification and Validation of a Detonation Computational Fluid Dynamics Model

2016 ◽  
Vol 366 ◽  
pp. 40-46
Author(s):  
Rui Li Wang ◽  
Xiao Liang ◽  
Wen Zhou Lin ◽  
Xue Zhe Liu ◽  
Yun Long Yu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Verification And Validation ◽  
Cfd Model ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Primary Means ◽  
Computational Fluid Dynamics Cfd ◽  
2D Space

Verification and validation (V&V) are the primary means to assess the accuracy and reliability in computational fluid dynamics (CFD) simulation. V&V of the multi-medium detonation CFD model is conducted by using our independently-developed software --- Lagrangian adaptive hydrodynamics code in the 2D space (LAD2D) as well as a large number of benchmark testing models. Specifically, the verification of computational model is based on the basic theory of the computational scheme and mathematical physics equations, and validation of the physical model is accomplished by comparing the numerical solution with the experimental data. Finally, some suggestions are given about V&V of the detonation CFD model.

The Simulation and Inspection for the Starting Phenomenon of Slit Coating Process on Glass Substrate

2011 ◽  
Vol 5 (2) ◽  
pp. 190-194
Author(s):  
Ta-Hsin Chou ◽  
◽  
Wen-Hsien Yang ◽  
Kuei-Yuan Cheng ◽  
Yu-Chen Chang ◽  
...  
Keyword(s):  
Feed Rate ◽  
Glass Substrate ◽  
Cfd Simulation ◽  
Fluid Flows ◽  
Ccd Camera ◽  
Cfd Model ◽  
Liquid Feed ◽  
Experimental Parameters ◽  
Computational Fluid Dynamics Cfd ◽  
Horizontal Moving

We developed a two-dimensional Computational Fluid Dynamics (CFD) model of a slit nozzle and coating for photoresist, using the Volume Of Fluid (VOF) to calculate the transient free surface. Parameters studied in simulation, including contact angle, liquid feed rate, slit gap, and coating gap. Simulation results yielded information on operation and buildup conditions, enabling us to examine microscopic fluid flows. Experiments used a slit coater (ITRI) having a slit nozzle 370 mm wide and a 100 µm slit gap, and set on a vertical moving table. A glass substrate was fixed on a horizontal moving table by a vacuum pump. Photoresist is pumped from a tank to the slit nozzle by a plunger. During coating, a CCD camera facing the slit gap imaged coating conditions. Experimental parameters studied included substrate speed, coating gap, and photoresist feed rate. The substrate was operated at 10 to 20 mm/second, the coating gap was set at 100 µm, and the photoresist feed rate was from 0.4 to 0.8 ml. Simulation and experimental results confirmed that CFD simulation was possible in designing the slit nozzle and preverifying coating. Photoresist coating was possible below 1.5 µm thick with 5%uniformity.

Investigation of Pressure Dependent Thermal Contact Resistance between Silver Metallized SiC Chip and DBC Substrate

2015 ◽  
Vol 821-823 ◽  
pp. 452-455 ◽  
Author(s):  
Zsolt Toth Pal ◽  
Ya Fan Zhang ◽  
Ilja Belov ◽  
Hans Peter Nee ◽  
Mietek Bakowski
Keyword(s):  
Heat Transfer ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Cfd Simulation ◽  
Thermal Contact ◽  
Cfd Model ◽  
Transfer Experiment ◽  
Transfer Path ◽  
Computational Fluid Dynamics Cfd ◽  
Pressure Independent

– Thermal contact resistances between a silver metallized SiC chip and a direct bonded copper (DBC) substrate have been measured in a heat transfer experiment. A novel experimental method to separate thermal contact resistances in multilayer heat transfer path has been demonstrated. The experimental results have been compared with analytical calculations and also with 3D computational fluid dynamics (CFD) simulation results. A simplified CFD model of the experimental setup has been validated. The results show significant pressure dependence of the thermal contact resistance but also a pressure independent part.

Frost Growth CFD Model of an Integrated Active Desiccant Rooftop Unit

2007 ◽  
Author(s):  
Patrick Geoghegan ◽  
Andrei Petrov ◽  
Edward Vineyard ◽  
Randall Linkous ◽  
Abdolreza Zaltash
Keyword(s):  
Cfd Simulation ◽  
Vapor Compression ◽  
Cfd Model ◽  
Outdoor Air ◽  
Transient Model ◽  
Space Cooling ◽  
Heat Transfer Capacity ◽  
Computational Fluid Dynamics Cfd ◽  
Heating Loads ◽  
Frost Growth

A frost growth model is incorporated into a Computational Fluid Dynamics (CFD) simulation of a heat pump by means of a user-defined function in a commercial CFD code. The transient model is applied to the outdoor section of an Integrated Active Desiccant Rooftop (IADR) unit in heating mode. IADR is a hybrid vapor compression and active desiccant unit capable of handling 100% outdoor air (dedicated outdoor air system) or as a total conditioning system, handling both outdoor air and space cooling or heating loads. The predicted increase in flow resistance and loss in heat transfer capacity due to frost build-up are compared to experimental pressure drop readings and thermal imaging. The purpose of this work is to develop a CFD model that is capable of predicting frost growth, a potentially valuable tool in evaluating the effectiveness of defrost-on-demand cycles.

scholarly journals Effect of the ridge position ratio on the thermal environment of the Chinese solar greenhouse

2021 ◽  
Vol 8 (5) ◽  
Author(s):  
Xiaoyang Wu ◽  
Xingan Liu ◽  
Xiang Yue ◽  
Hui Xu ◽  
Tianlai Li ◽  
...  
Keyword(s):  
Structural Design ◽  
Cfd Simulation ◽  
Thermal Environment ◽  
The South ◽  
The North ◽  
Dependency Relationship ◽  
Solar Greenhouse ◽  
Computational Fluid Dynamics Cfd ◽  
North Wall ◽  
Maximum Air Temperature

This paper clarified the mechanism of the south and north roofs' effect on the thermal environment of the Chinese solar greenhouse (CSG), using a new parameter: ridge position ratio (RPR), which can describe the dynamic dependency relationship between the south and north roofs. A mathematical model was established using a method of combining computational fluid dynamics (CFD) simulation with experiments, then the model was used to further analyse the effect of RPR on the thermal environment of the CSG. The experimental greenhouse was simulated as an empty building to obtain results independently from these factors including crop and ventilation conditions. The results showed that the occurrence time of the maximum air temperature will be delayed when RPR increases to 0.3 during the daytime. As RPR increases, the heat storage layer of the soil gradually becomes thinner, but the north wall remains unchanged. RPR has a relatively small effect on the minimum temperature of each greenhouse part during the night. Mathematical models of the relationships between RPR, the solar energy that entered the greenhouse and the released heat energy of the enclosure structures were established, respectively. This paper can provide theoretical guidance for the structural design of the CSG.

CFD Simulation of Heat Transfer of Pulsating Gas in a Pipe

2014 ◽  
Vol 687-691 ◽  
pp. 623-626
Author(s):  
Zhi Ren Yin ◽  
Li Jun Yang ◽  
Run Ze Duan
Keyword(s):  
Heat Transfer ◽  
Cfd Simulation ◽  
Cfd Model ◽  
Pulse Combustor ◽  
Flow Development ◽  
Steady Flow Condition ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
High Level ◽  
The Heat Transfer Coefficient

Numerical Simulation of pulsating flow in a pulse combustor tailpipe was performed using computational fluid dynamics (CFD) method. The flow in the pipe was characterized by periodic pulsating. The influence of this pulsating includes incomplete flow development and high level of convective heat transfer rate, and both were considered and investigated by the CFD model. Compared with the steady flow condition, results showed that the heat transfer coefficient and Nusselt number were 2.35 times higher.

Computational Fluid Dynamics (CFD) Simulation of Liquid-Liquid Mixing in Mixer Settler

2012 ◽  
Vol 57 (1) ◽  
pp. 173-178 ◽  
Author(s):  
M. Shabani ◽  
A. Mazahery
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Process Simulation ◽  
Chemical Process ◽  
Cfd Simulation ◽  
Complex Geometry ◽  
Physical Parameters ◽  
Cfd Model ◽  
Liquid Mixing ◽  
Computational Fluid Dynamics Cfd

Computational Fluid Dynamics (CFD) Simulation of Liquid-Liquid Mixing in Mixer Settler Mixer-settlers are widely used inmetallurgical, mineral and chemical process. One of the greatest challenges in the area of hydrometallurgy process simulation is agitation made by impeller inside mixer-settler which yet presents one of the most common operations. Computational fluid dynamics (CFD) model has been developed to predict the effect of different physical parameters including temperature and density on the mixing characteristics of the system. It is noted that non-isotropic nature of flow in a mixer-settler, the complex geometry of rotating impellers and the large disparity in geometric scales present are some of the factors which contribute to the simulation difficulty. The experimental data for different velocity outlet was also used in order to validate the model.

scholarly journals CFD simulation of temperature and airflow inside a shipping container size plant factory for optimal lettuce production

Food Research ◽  
2020 ◽  
Vol 4 (S6) ◽  
pp. 54-59
Author(s):  
A. Mohd Noh ◽  
M.A. Mohamad Tahir ◽  
S. Mat ◽  
M.H. Dzulkifli
Keyword(s):  
Temperature Distribution ◽  
Cfd Simulation ◽  
Percentage Error ◽  
Control Environment ◽  
Cfd Model ◽  
Alternative Design ◽  
Shipping Container ◽  
Plant Factory ◽  
Computational Fluid Dynamics Cfd ◽  
Growing Conditions

Computational fluid dynamics (CFD) have been playing an increasingly important role in designing the agriculture control environment structure in the past few years. Plant factory is a fully enclose control environment agriculture structure developed to create optimum growing conditions for the crops. Previous studies have proven that the CFD technique was able to analyse and predict the internal climate of the plant factory in the designing stage before the actual plant was built. This study was conducted to analyse the changes in airflow characteristics and temperature distribution in a shipping container size plant factory with different inlet and outlet locations. Uniformity of airflow and temperature distribution was important in plant factories as it is responsible to create optimum and uniform growing conditions for crops. The CFD model was validated by comparing simulation and experimental data of existing plant factory inlet and outlet location. The validation result shows an acceptable percentage error between simulated and measured data. Two alternative design of the inlet and outlet location was simulated to improve the uniformity of airflow and temperature distribution. The validated CFD model was then used to simulate the alternative design. Finally, the location of the inlet and the outlet that produce the most uniform airflow and temperature distribution inside the plant factory was identified.

scholarly journals Transient 3D CFD Simulation of a Stationary Vane, Oil Free, Rotary Compressor

2019 ◽  
Vol 63 (4) ◽  
pp. 308-318 ◽  
Author(s):  
Balázs Farkas ◽  
Jenő Miklós Suda
Keyword(s):  
Cfd Simulation ◽  
Piston Compressor ◽  
Working Fluid ◽  
Rotary Compressor ◽  
Heat Sources ◽  
Cfd Model ◽  
Cfd Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Rolling Piston ◽  
Good Agreement

The evaluation of a newly designed oil-free rotary compressor is presented based on transient 3D Computational Fluid Dynamics (CFD) simulations. The simulations are performed at low compression ratios and low pressure ratios and low rotational speeds. To place the results into context, the data presented in related literature was processed and summarized. The methods related to the CFD model of the newly designed compressor were developed, summarized and evaluated. The accessed CFD data are in good agreement with the results of the former rolling piston compressor related investigations. The oil free operation prevents the contamination of the working fluid from lubricant. Since the compressor is planned to work in open cycle within the sensitive environment of thermal heat sources contamination free operation has to be accomplished. However, oil-free operation also results in significantly lower performance based on the modelling results.

CFD Simulation of Droplet Formation under Various Parameters in Prilling Process

2014 ◽  
Vol 625 ◽  
pp. 394-397 ◽  
Author(s):  
Aadil Muhammad ◽  
Rajashekhar Pendyala ◽  
Nejat Rahmanian
Keyword(s):  
Weber Number ◽  
Cfd Simulation ◽  
Liquid Velocity ◽  
Droplet Formation ◽  
Droplet Breakup ◽  
Cfd Model ◽  
Vof Model ◽  
Computational Fluid Dynamics Cfd ◽  
Velocity Pressure ◽  
Surface Tension Forces

A computational fluid dynamics (CFD) model is used to investigate the droplet formation and deformation under the influence of different parameters. Droplet breakup phenomenon depends on several factors such as viscosity, velocity, pressure difference, and geometry. The most important parameter for droplet breakup is the Weber number (We) which is the ratio of disrupting aerodynamics forces to the surface tension forces. Volume of fluid (VOF) model is used in present work to simulate the droplet breakup. This work presents the effect of liquid velocity, viscosity, and orifice diameters on droplet formation and breakup.

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