scholarly journals Distributed Propulsion Systems for Shallow Draft Vessels

2020 ◽  
Vol 8 (9) ◽  
pp. 667 ◽  
Author(s):  
Ladislav Illes ◽  
Tomas Kalina ◽  
Martin Jurkovic ◽  
Vladimir Luptak
Keyword(s):  
Fluid Dynamics ◽  
Shallow Water ◽  
Deep Water ◽  
Cfd Simulation ◽  
Flow Speed ◽  
Propulsion Systems ◽  
Distributed Propulsion ◽  
Discrete Flow ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact

The aim of this study was to investigate the impact of distributed propulsion systems used on inland and coastal navigation in shallow water. Five layouts were assessed by computational fluid dynamics (CFD) simulation. The hull/propulsion layout cases have been analyzed for discrete flow speed values in the range 0–6 m/s. All cases have been examined under restricted draft conditions in shallow water with a minimum of 0.3 m under keel clearance (UKC) and under unrestricted draft conditions in deep water. The results show that distributed propulsion consisting of 6 or 8 (in some cases, even more) units produces noticeable higher thrust effects in shallow water than the traditional layout. Under restricted conditions, the thrust increase between two distributed layouts with different numbers of propulsors is higher, in contrast to deep water, where differences in performance are not so significant.

The Impact of Different Types of Permeable Pavement Utilization on Air Temperature above the Pavement

2013 ◽  
Vol 723 ◽  
pp. 678-685 ◽  
Author(s):  
Jyh Dong Lin ◽  
Chen Yu Hsu ◽  
Andika Citraningrum ◽  
Putri Adhitana
Keyword(s):  
Fluid Dynamics ◽  
Air Temperature ◽  
Asphalt Concrete ◽  
Cfd Simulation ◽  
Concrete Block ◽  
Permeable Pavement ◽  
Different Types ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact

This study investigate permeable pavement utilization and its impact on air temperature by using site measurement, statistical analysis, and Computational Fluid Dynamics (CFD) simulation. National Central University (NCU) main library is the case study for the simulations. Simulations on five pavement types (dense grade asphalt concrete/DGAC, permeable asphalt concrete/PAC, concrete, permeable interlocking concrete block/PICB, and grass block) shows that grass block and PICB can reduce air temperature, while three others increase air temperature.

Study of the Impact of Quenching Process Parameters in High Dimension Rings of Steel AISI 4140

2012 ◽  
Vol 1372 ◽  
Author(s):  
C. Márquez ◽  
E. Martínez ◽  
J. Cárdenas ◽  
O. Saldívar ◽  
J. Rodríguez ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
High Dimension ◽  
Analytical Study ◽  
Cfd Simulation ◽  
Aisi 4140 ◽  
Quenching Process ◽  
Steel Aisi ◽  
Computational Fluid Dynamics Cfd ◽  
Tank Design ◽  
The Impact

ABSTRACTManufacturing of high dimension steel rings impose several technological challenges. The lack of understanding of the principles and practices of quenching can result in inadequate hardness, excessive distortion or scrapping of costly machined components. This paper presents the results of an analytical study of the parameters of the quenching operation, among them the fluid dynamics of the agitation in the quenching media. Velocity components of the fluid were measured using an anemometer inside the quenching tank. Uniformity of agitation is compared with a Computational Fluid Dynamics (CFD) simulation. The CFD results revealed the impact of quench tank design, configuration and operation of impellers.

scholarly journals Computational Fluid Dynamics (CFD) Simulation on Mixing in T-Shaped Micromixer

2020 ◽  
Vol 932 ◽  
pp. 012006
Author(s):  
S N A Ahmad Termizi ◽  
C Y Khor ◽  
M A M Nawi ◽  
Nurlela Ahmad ◽  
Muhammad Ikman Ishak ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Computational Fluid Dynamics Cfd

A Study on the Performance of Stratified Air Conditioning Design in Assembly Halls – A Case Study at the Dazhi Cultural Center in Taiwan

2013 ◽  
Vol 368-370 ◽  
pp. 599-602 ◽  
Author(s):  
Ian Hung ◽  
Hsien Te Lin ◽  
Yu Chung Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Air ◽  
Air Conditioning ◽  
Cfd Simulation ◽  
Indoor Temperature ◽  
Cultural Center ◽  
Computational Fluid Dynamics Cfd

This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between all-zone air conditioning design and stratified air conditioning design. The results have strong implications for air conditioning design and can improve the indoor air quality of assembly halls.

Effect of Buoyancy and Density Ratio on Heat Transfer in a Smooth Cooling Channel of a Gas Turbine Blade

2018 ◽  
Author(s):  
Mandana S. Saravani ◽  
Saman Beyhaghi ◽  
Ryoichi S. Amano
Keyword(s):  
Heat Transfer ◽  
Rotational Speed ◽  
Cfd Simulation ◽  
Density Ratio ◽  
Reynolds Numbers ◽  
Buoyancy Effect ◽  
Square Channel ◽  
First Case ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact

The present work investigates the effects of buoyancy and density ratio on the thermal performance of a rotating two-pass square channel. The U-bend configuration with smooth walls is selected for this study. The channel has a square cross-section with a hydraulic diameter of 5.08 cm (2 inches). The lengths of the first and second passes are 514 mm and 460 mm, respectively. The turbulent flow enters the channel with Reynolds numbers of up to 34,000. The rotational speed varies from 0 to 600 rpm with the rotational numbers up to 0.75. For this study, two approaches are considered for tracking the buoyancy effect on heat transfer. In the first case, the density ratio is set constant, and the rotational speed is varied. In the second case, the density ratio is changed in the stationary case, and the effect of density ratio is discussed. The range of Buoyancy number along the channel is 0–6. The objective is to investigate the impact of Buoyancy forces on a broader range of rotation number (0–0.75) and Buoyancy number scales (0–6), and their combined effects on heat transfer coefficient for a channel with aspect ratio of 1:1. Several computational fluid dynamics (CFD) simulation are carried out for this study, and some of the results are validated against experimental data.

scholarly journals The Protect Air Film of an Exterior Window

2021 ◽  
Author(s):  
Sanaz Dianat
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Glass Temperature ◽  
Experimental Procedure ◽  
Wind Speeds ◽  
Computational Fluid Dynamics Cfd ◽  
Air Film ◽  
The Impact

The research paper investigates the impact of a window’s exterior air film on the assembly temperature. The exterior air film constitutes a vital portion of a window’s insulating values. The air film increases the temperature of the window exterior pane to a temperature above ambient temperature. The air film also rises the interior glass temperature and reduces the heat transfer from the interior surface. According to computational fluid dynamics (CFD), the air film is removed in windy conditions, decreasing the window temperature on the outside as well as on the inside. The idea behind the project is to carry out an experimental procedure on three different windows to validate the CFD results, which indicates the effect of various wind speeds. Keyword: Exterior air film, computational fluid dynamics, window assembly, wind speed

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