scholarly journals Design and Numerical Study of the Novel Manifold Header for the Evacuated Tube Solar Collector

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2450
Author(s):  
Martin Beer ◽  
Radim Rybár ◽  
Michal Cehlár ◽  
Sergey Zhironkin ◽  
Peter Sivák
Keyword(s):  
Numerical Study ◽  
Cfd Analysis ◽  
The Novel ◽  
Design Elements ◽  
Serial Connection ◽  
Final Design ◽  
Computational Fluid Dynamics Cfd ◽  
Evacuated Tube ◽  
Prototype Phase ◽  
Selection Of

The presented paper dealt with the concept of an innovative manifold header for evacuated tube solar collectors. The proposed concept eliminates the drawbacks of conventional manifold headers, especially the serial connection of heat pipes that operate under uneven conditions. The advantage of the proposed design of the manifold header is also an increase in the heat exchange surface and the possibility of conducting the heat transfer media flow in a parallel flow arrangement, which increases the overall efficiency. The concept of the manifold header was evaluated on five variations of design with the use of the computational fluid dynamics (CFD) analysis. The results of the CFD analysis confirmed the functionality of the concept and also enabled the selection of the most suitable design elements, which were incorporated into the final design of a manifold header in the pre-prototype phase of manufacturing.

Stent-Induced Vascular Remodeling in Two-Step Stent-Assisted Coiling Treatment of Brain Aneurysms: A Closer Look Into the Hemodynamic Changes During the Stent Healing Period

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Gabriel B. Santos ◽  
Iago Oliveira ◽  
José L. Gasche ◽  
Julio Militzer ◽  
Carlos E. Baccin
Keyword(s):  
Vascular Remodeling ◽  
Treatment Process ◽  
Geometric Analysis ◽  
Cfd Analysis ◽  
The Novel ◽  
Hemodynamic Changes ◽  
Stent Deployment ◽  
Healing Period ◽  
Treatment Stage ◽  
Computational Fluid Dynamics Cfd

Abstract Stenting has become an important adjunctive tool for assisting coil embolization in complex-shaped intracranial aneurysms. However, as a secondary effect, stent deployment has been related to both immediate and delayed remodeling of the local vasculature. Recent studies have demonstrated that this phenomenon may assume different roles depending on the treatment stage. However, the extent of such event on the intra-aneurysmal hemodynamics is still unclear; especially when performing two-step stent-assisted coiling (SAC). Therefore, we performed computational fluid dynamics (CFD) analysis of the blood flow in four bifurcation aneurysms focusing on the stent healing period found in SAC as a two-step maneuver. Our results show that by changing the local vasculature, the intra-aneurysmal hemodynamics changes considerably. However, even though changes do occur, they were not consistent among the cases. Furthermore, by changing the local vasculature not only the shear levels change but also the shear distribution on the aneurysm surface. Additionally, a geometric analysis alone can mislead the estimation of the novel hemodynamic environment after vascular remodeling, especially in the presence of mixing streams. Therefore, although the novel local vasculature might induce an improved hemodynamic environment, it is also plausible to expect that adverse hemodynamic conditions might occur. This could pose a particularly delicate condition since the aneurysm surface remains completely exposed to the novel hemodynamic environment during the stent healing period. Finally, our study emphasizes that vascular remodeling should be considered when assessing the hemodynamics in aneurysms treated with stents, especially when evaluating the earlier stages of the treatment process.

scholarly journals Experimental and Numerical Study of Orifice Coefficient of Cargo Tank Design of LNG Vessels

2020 ◽  
Vol 10 (19) ◽  
pp. 6667
Author(s):  
Se-Yun Hwang ◽  
Kwang-Sik Kim ◽  
Ho-Sang Jang ◽  
Jang-Hyun Lee
Keyword(s):  
Numerical Study ◽  
Operating Pressure ◽  
Cfd Analysis ◽  
Storage Tanks ◽  
Insulation System ◽  
Design Factor ◽  
International Regulations ◽  
Computational Fluid Dynamics Cfd ◽  
Tank Design ◽  
Cfd Method

Liquid cargo storage tanks of liquefied natural gas (LNG) carriers are designed by strict standards to maintain the cryogenic state (−163 °C). For most LNG cargo storage tanks, it is mandatory to install a system that can safely store leaked fluid for 15 days in the case of leakage of liquid cargo due to crack of the insulation system. To ensure safety, it is necessary to predict the amount of LNG spilling from the cracks in the insulation panels. Although international regulations are provided, they rely on a conservative and consistent coefficient. In this study, experimental and numerical methods were applied to examine the design factor used to predict the flow rate in the tank design process. To check the amount of leakage that occurs under pressure conditions of LNG tanks, an experiment was conducted using crack specimens and pressure containers filled with water. In order to simulate the leakage of LNG, the amount of leakage was predicted using the Computational Fluid Dynamics (CFD) method. The distribution of leakage quantity was investigated according to the shape of the crack through the pressure vessel experiment and the analysis. Through CFD analysis, the leakage rate of LNG was calculated for each operating pressure condition through the crack. Finally, the results of this study examined the need to identify and reconsider the coefficients due to international guidelines and other factors in calculating orifice coefficients applied to the design of LNG tanks.

Three-Dimensional CFD Analysis on Gas Flow in Corrugated Wall Channel

2006 ◽  
Author(s):  
Nam-il Tak ◽  
Won-Jae Lee ◽  
Jonghwa Jang
Keyword(s):  
Heat Exchanger ◽  
Turbulent Flows ◽  
Gas Flow ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Cfd Analysis ◽  
Intermediate Heat Exchanger ◽  
Computational Fluid Dynamics Cfd ◽  
Corrugated Wall ◽  
Selection Of

A printed circuit heat exchanger (PCHE) is known as one of the promising types for an intermediate heat exchanger (IHX) of a nuclear hydrogen production system. This paper presents fundamental numerical results on gas flow behaviors in a typical PCHE geometry. Laminar and turbulent flows were analyzed based on a computational fluid dynamics (CFD) analysis. Local friction coefficient and local Nusselt number were evaluated and compared with those by typical correlations for tubes. In the case of a turbulent flow, various turbulence models were applied. The results clearly show the significance of a careful selection of a turbulence model.

Effect of Vortex Induced Vibration on a Paired-Column Semisubmersible Platform

2015 ◽  
Vol 15 (08) ◽  
pp. 1540019 ◽  
Author(s):  
Agbomerie Charles Odijie ◽  
Jianqiao Ye
Keyword(s):  
Fluid Dynamics ◽  
Vortex Shedding ◽  
Numerical Study ◽  
Incidence Angle ◽  
Maximum Amplitude ◽  
Weather Conditions ◽  
Cfd Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Rectangular Columns ◽  
Effect Of Surface

This paper describes a numerical study of the effect of vortex induced movement (VIM) on the hull of a paired-column semisubmersible (pc-semi) platform in relation to the column geometric properties. A computational fluid dynamics (CFD) analysis was carried out and vortex shedding was observed. The response of the square and rectangular columns hull configuration was investigated using ANSYS AQWA and the maximum amplitude was observed to be almost the same for both geometry, but it occurred at different range of reduced velocity Vr. The effect of surface wave and flow incidence angle were investigated for extreme and regular weather conditions, and it was found that VIM occurred at 2 ≤ Vr ≤ 12.

scholarly journals CFD-Based Selection of Dispersion Plates

2018 ◽  
Vol 232 ◽  
pp. 03047
Author(s):  
Jing Chen ◽  
Ning Deng ◽  
Guoyong Wu ◽  
Jinqing Zhou
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Analysis ◽  
Flow Conditions ◽  
Dispersion Effects ◽  
Velocity Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Selection Of

Computational Fluid Dynamics (CFD) technology was used to analyse dispersion effects of 3 plates of different structures during adhesives production. Three models of the dispersion plates were designed: (1) Project 1: a plate with sharp and short teeth, (2) Project 2: a plate with sharp and long teeth, (3) Project 3: a plate with blunt and long teeth. Pictures of velocity flow contours and flow trajectories in the CFD analysis were obtained to show the flow conditions inside the Reactor. Particle studies were also run to predict adhesive particles dispersion effects of these 3 kinds of plates, so that the best structure of the plate would be chosen.

Design Analysis of the Volumatic: A CFD and Experimental Study

2002 ◽  
Author(s):  
Vahid Jalili ◽  
Mayur K. Patel ◽  
Christopher Bailey ◽  
Steve Begg ◽  
Henk Versteeg ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Study ◽  
Laser Doppler Anemometry ◽  
Cfd Analysis ◽  
The Novel ◽  
Initial Part ◽  
Cfd Model ◽  
Novel Approach ◽  
Computational Fluid Dynamics Cfd ◽  
Visualization Techniques

The aim of this paper has been to describe the novel approach adopted in studying the flow field within the Volumatic. In this study a combination of engineering tools such as Computational Fluid Dynamics (CFD), Laser Doppler Anemometry (LDA) and Flow visualization techniques have been employed. The initial part of the study involved the use of CFD in modelling the drug entering the Volumatic. The CFD model was then validated against measurements made using LDA. The agreement obtained was very good; this was particularly encouraging as the CFD analysis was carried out some six months prior to the experimental study.

scholarly journals Design of Novel Flash Ironmaking Reactors for Greatly Reduced Energy Consumption and CO2 Emissions

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 332
Author(s):  
Hong Yong Sohn ◽  
De-Qiu Fan ◽  
Amr Abdelghany
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Large Diameter ◽  
Reduction Reaction ◽  
The Novel ◽  
Height Ratio ◽  
Fine Iron ◽  
Computational Fluid Dynamics Cfd ◽  
High Reduction ◽  
Iron Ore Concentrate

The development of a novel ironmaking technology based on fine iron ore concentrate in a flash reactor is summarized. The design of potential industrial reactors for flash ironmaking based on the computational fluid dynamics technique is described. Overall, this simulation work has shown that the size of the reactor used in the novel flash ironmaking technology (FIT) can be quite reasonable vis-à-vis the blast furnaces. A flash reactor of 12 m diameter and 35 m height with a single burner operating at atmospheric pressure would produce 1.0 million tons of iron per year. The height can be further reduced by either using multiple burners, preheating the feed gas, or both. The computational fluid dynamics (CFD)-based design of potential industrial reactors for flash ironmaking pointed to a number of features that should be incorporated. The flow field should be designed in such a way that a larger portion of the reactor is used for the reduction reaction but at the same time excessive collision of particles with the wall must be avoided. Further, a large diameter-to-height ratio that still allows a high reduction degree should be used from the viewpoint of decreased heat loss. This may require the incorporation of multiple burners and solid feeding ports.

Load Characteristics of Steel and Concrete Tubular Members Under Jet Fire: An Experimental and Numerical Study

2010 ◽  
Author(s):  
Jeong Hyo Park ◽  
Bong Ju Kim ◽  
Jung Kwan Seo ◽  
Jae Sung Jeong ◽  
Byung Keun Oh ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Numerical Study ◽  
Fire Load ◽  
Adiabatic Wall ◽  
Fire Engineering ◽  
Ansys Cfx ◽  
Design Values ◽  
Computational Fluid Dynamics Cfd ◽  
Load Characteristics ◽  
Set Up

The aim of this study was to evaluate the load characteristics of steel and concrete tubular members under jet fire, with the motivation to investigate the jet fire load characteristics in FPSO topsides. This paper is part of Phase II of the joint industry project on explosion and fire engineering of FPSOs (EFEF JIP) [1]. To obtain reliable load values, jet fire tests were carried out in parallel with a numerical study. Computational fluid dynamics (CFD) simulation was used to set up an adiabatic wall boundary condition for the jet fire to model the heat transfer mechanism. A concrete tubular member was tested under the assumption that there is no conduction effect from jet fire. A steel tubular member was tested and considered to transfer heat through conduction, convection, and radiation. The temperature distribution, or heat load, was analyzed at specific locations on each type of member. ANSYS CFX [2] and Kameleon FireEx [3] codes were used to obtain similar fire action in the numerical and experimental methods. The results of this study will provide a useful database to determine design values related to jet fire.

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