Anti-Cavitation Approach in a Bio-Inspired Throttle Valve: A Study of Using Rubber-Like Materials

2020 ◽  
Vol 976 ◽  
pp. 55-61
Author(s):  
Vishwanath Pooneeth ◽  
Xu He ◽  
Hai Hang Wang ◽  
Mlela Masoud Kamoleka
Keyword(s):  
Static Pressure ◽  
Water Layer ◽  
Molecular Study ◽  
Binding Energies ◽  
Radius Of Gyration ◽  
Valve Seat ◽  
Ansys Fluent ◽  
Throttle Valve ◽  
Computational Fluid Dynamics Cfd ◽  
Hildebrand Solubility Parameter

This multiscale molecular study emphasizes on reducing cavitation in a squid - inspired throttle valve. Molecular simulations on 10 different polymers bonded layer-wise to Iron (III) Oxide were done and the 5 ones having the strongest binding energies were further relaxed using xenon crystals (0.2ns). Changes in the radius of gyration were observed and post relaxation, the interaction energy, the cohesive energy density, and the Hildebrand solubility parameter of the polymer-water layer were determined. Consequently, Polytetrafluoroethylene (PTFE) chosen from the results was further equilibrated for 1.05 ns. To verify its wettability, a contact angle (water nanodroplet) of 115° was estimated. Next, the lined (3mm thick PTFE) valve seat of the chosen throttle valve was numerically analyzed. The computational fluid dynamics (CFD) code, ANSYS Fluent 17.0 was used to test the 3D model with assigned boundary conditions to determine the vapor fraction and the static pressure. Finally, thickness optimization of the lining was done to improve the valve’s performance within the fluid power system and minimize cost involvement.

Non-Newtonian Computational Fluid Dynamics (CFD) Modeling on Left Coronary Artery with Multiple Blockages

2014 ◽  
Vol 592-594 ◽  
pp. 1924-1929
Author(s):  
Krishna Murari Pandey ◽  
Ritabrata Thakur ◽  
Abhinav Hazarika ◽  
Tarun Ashutosh ◽  
Dipankar Gogoi
Keyword(s):  
Coronary Artery ◽  
Static Pressure ◽  
Three Dimensional ◽  
Simulation Software ◽  
Cfd Modeling ◽  
Ansys Fluent ◽  
Viscous Losses ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
Dimensional Section

The rate of mean blood flow through arteries depend on the resistance to flow presented by the blood vessels. Mean blood pressure decreases as the circulating blood moves away from the heart through arteries and capillaries due to viscous losses of energy. Atherosclerosis is a common phenomenon that is observed causing blockage in coronary arteries leading to cardiac arrest. This blockage is due to the deposition of cholesterol or plaque on the inner walls of the coronary artery. This paper provides an analytical study on the variation of static pressure with multiple blockages in the artery implementing the conventional simulation software. A general three dimensional section of the coronary artery was taken for the analysis and the variation of static pressure with increase in the number of blockages due to cholesterol deposition was studied. Meshing of the geometry and specification of the boundary types have been accomplished using GAMBIT 2.3.16 and the analysis has been carried out using ANSYS FLUENT 6.3.26.

scholarly journals Experimental and CFD Simulations of the Aerosol Flow in the Air Ventilating the Underground Excavation in Terms of SARS-CoV-2 Transmission

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4743
Author(s):  
Tomasz Janoszek ◽  
Zbigniew Lubosik ◽  
Lucjan Świerczek ◽  
Andrzej Walentek ◽  
Jerzy Jaroszewicz
Keyword(s):  
Numerical Calculations ◽  
Mining Institute ◽  
Ventilation Network ◽  
Underground Excavation ◽  
In Situ Tests ◽  
Ansys Fluent ◽  
Aerosol Emission ◽  
Ansys Cfx ◽  
Computational Fluid Dynamics Cfd

The paper presents the results of experimental and model tests of transport of dispersed fluid droplets forming a cloud of aerosol in a stream of air ventilating a selected section of the underground excavation. The excavation selected for testing is part of the ventilation network of the Experimental Mine Barbara of the Central Mining Institute. For given environmental conditions, such as temperature, pressure, relative humidity, and velocity of air, the distribution of aerosol droplet changes in the mixture of air and water vapor along the excavation at a distance was measured at 10 m, 25 m, and 50 m from the source of its emission. The source of aerosol emission in the excavation space was a water nozzle that was located 25 m from the inlet (inlet) of the excavation. The obtained results of in situ tests were related to the results of numerical calculations using computational fluid dynamics (CFD). Numerical calculations were performed using Ansys-Fluent and Ansys-CFX software. The dimensions and geometry of the excavation under investigation are presented. The authors describe the adopted assumptions and conditions for the numerical model and discuss the results of the numerical solution.

Analysis of Late Phase Severe Accident Phenomena in CANDU Plant

2017 ◽  
Vol 3 (2) ◽  
Author(s):  
D. Dupleac
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Late Phase ◽  
Severe Accident ◽  
Ansys Fluent ◽  
Water Depletion ◽  
Sources Of Uncertainty ◽  
Parametric Studies ◽  
Computational Fluid Dynamics Cfd ◽  
Containment Pressure

The paper overviews the analytical studies performed at Politehnica University of Bucharest on the analysis of late phase severe accident phenomena in a Canada Deuterium Uranium (CANDU) plant. The calculations start from a dry debris bed at the bottom of calandria vessel. Both SCDAPSIM/RELAP code and ansys-fluent computational fluid dynamics (CFD) code are used. Parametric studies are performed in order to quantify the effect of several identified sources of uncertainty on calandria vessel failure: metallic fraction of zirconium inside the debris, containment pressure, timing of water depletion inside calandria vessel, steam circulation in calandria vessel above debris bed, debris temperature at moment of water depletion inside calandria vessel, calandria vault nodalization, and the gap heat transfer coefficient.

scholarly journals EFFECT OF GALLERIES ON THE WIND FLOW STRUCTURE AND POLLUTANT TRANSPORT WITHIN STREET CANYONS WITH OR WITHOUT FACADE ROUGHNESS ELEMENTS (BALCONIES)

2020 ◽  
Vol 7 (12) ◽  
pp. 45-59
Author(s):  
V. A. Karkoulias ◽  
P. E. Marazioti ◽  
D. P. Georgiou ◽  
E. A. Maraziotis
Keyword(s):  
Flow Field ◽  
Concentration Distribution ◽  
Cfd Simulation ◽  
Field Structure ◽  
Flow Structures ◽  
Street Canyons ◽  
Ansys Fluent ◽  
Roughness Elements ◽  
Computational Fluid Dynamics Cfd ◽  
The Vertical Distribution

This paper investigates how the structure of the flow field and the vertical distribution of the pollutant concentration near the wall facades of street canyons are affected by the presence of some elements such as street level galleries. Numerical results are presented for various gallery geometries in combination with facade roughness elements (balconies) for a canyon of an aspect ratio equal to h/w=2.33. The results were obtained by a Computational Fluid Dynamics (CFD) simulation employing the ANSYS-FLUENT suite that incorporated the k-e turbulent (RNG) model. The simulation generated several flow structures inside the canyon (mainly vortices), whose characteristic properties (e.g. number, strength and size) are discussed in terms of the effect of the galleries on the flow field structure and the roughness generated by the building façade balconies. The results indicate a significant influence on both the flow field structure and the mass concentration distribution of the polluting particles.

scholarly journals OPTIMIZING THE VELOCITY OF RING SHAPE PARAMETER FOR DESIGNING THE NOZZLES USING CFD

2021 ◽  
pp. 1-10
Author(s):  
Obai Younis ◽  
Reem Ahmed ◽  
Ali Mohammed Hamdan ◽  
Dania Ahmed
Keyword(s):  
Shape Parameter ◽  
Maximum Velocity ◽  
Simulation Software ◽  
Governing Equations ◽  
Ansys Fluent ◽  
Ring Shape ◽  
Ring Location ◽  
Computational Fluid Dynamics Cfd ◽  
Triangular Elements ◽  
Volume Method

This study aims to optimize the velocity of ring shape parameter for designing the nozzles using computational fluid dynamics (CFD) and investigated the flow in nozzles using ANSYS, Inc. simulation software. The model geometries were defined using ANSYS FLUENT-Design Modeler platform. All nozzles were designed on unstructured triangular elements comprising of 1200000 mesh nodes. The differential governing equations were applied in ANSYS FLUENT based on a finite volume method. The distance and dimensions of ring location significantly influence the velocity of water during flow where the maximum velocity at double rings reduces the surface area at distance of 7mm and 15mm and 2x2 mm dimensions. Considering 8, 10, and 12 bar liner proportions, there was an increase in the velocity at maximum points in ring shapes.

Computer Analysis of S822 Aerofoil Section for Blades of Small Wind Turbines at Low Wind Speed

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Prachi R. Prabhukhot ◽  
Aditya R. Prabhukhot
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Cfd Simulation ◽  
Maximum Velocity ◽  
Small Scale ◽  
Blade Profile ◽  
Ansys Fluent ◽  
Low Wind Speed ◽  
Upward Direction ◽  
Computational Fluid Dynamics Cfd

The power generated in wind turbine depends on wind speed and parameters of blade geometry like aerofoil shape, blade radius, chord length, pitch angle, solidity, etc. Aerofoil selection is the crucial factor in establishing the efficient wind turbine. More than one aerofoil in a blade can increase the efficiency further. Previous studies of different aerofoils have shown that efficiency of small scale wind turbine increases when NREL S822 aerofoil is used for wind speed on and above 10 m/s. This paper introduces a study on effect of low wind speed (V = 5 m/s) on performance of blade profile. Aerofoils NREL S822/S823 are used for microwind turbine with S823 near root and S822 near tip. Blade of 3 m radius with spherical tubercles over entire span is analyzed considering 5 deg angle of attack. The computational fluid dynamics (CFD) simulation was carried out using ANSYS fluent to study the behavior of blade profile at various contours. The study shows that blade experiences maximum turbulence and minimum pressure near trailing edge of the tip of blade. The region also experiences maximum velocity of the flow. These factors result in pushing the aerofoil in upward direction for starting the wind turbine to rotate at the speed as low as 5 m/s.

Hydrate-Induced Vibration in an Offshore Pipeline

SPE Journal ◽  
2019 ◽  
Vol 25 (02) ◽  
pp. 732-743
Author(s):  
M. M. Jujuly ◽  
Mohammad Azizur Rahman ◽  
Aaron Maynard ◽  
Matthew Adey
Keyword(s):  
Gas Hydrate ◽  
Complex Geometry ◽  
Petroleum Industry ◽  
Offshore Structures ◽  
Flow Induced Vibration ◽  
Ansys Fluent ◽  
Safety Measures ◽  
Breakup Mechanism ◽  
Offshore Pipeline ◽  
Computational Fluid Dynamics Cfd

Summary Gas-hydrate plugging poses an operational challenge to offshore petroleum production and transportation. In this study, a computational-fluid-dynamics (CFD) model that uses ANSYS Fluent (ANSYS 2019) multiphase-flow-modeling techniques to simulate and analyze the effect of gas-hydrate flow in pipelines is proposed. For this purpose, the study attempted to integrate the ANSYS Fluent model with an existing commercial subsea-pipeline-visualization tool. To validate the simulation results, two case studies were conducted. The first study was about a pipeline whose dimensions are based on the specifications in existing literature (Balakin et al. 2010a). The second study was about a pipeline with more-complex geometry (M-shaped jumper with six elbows). The Eulerian/Eulerian method was used to model the multiphase hydrate flow. The population-balance method (PBM) was then used to model hydrate agglomeration and its breakup mechanism in the flow. A parametric study of the stresses in the pipelines resulting from flow-induced vibration (FIV) was conducted to identify the regions that underwent the maximum stresses and deformations under various flow conditions. The tool can be used in the petroleum industry to identify the operational hazards in offshore structures and to take necessary safety measures to avoid any potential catastrophic events.

scholarly journals STH/CFD Coupled Simulation of the Protected Loss of Flow Accident in the CIRCE-HERO Facility

2020 ◽  
Vol 10 (20) ◽  
pp. 7032 ◽  
Author(s):  
Pucciarelli Andrea ◽  
Galleni Francesco ◽  
Moscardini Marigrazia ◽  
Martelli Daniele ◽  
Forgione Nicola
Keyword(s):  
Thermal Stratification ◽  
Outlet Section ◽  
Experimental Conditions ◽  
Ansys Fluent ◽  
Internal Loop ◽  
Fuel Pin ◽  
Mass Flow Rates ◽  
Computational Fluid Dynamics Cfd ◽  
The University ◽  
Good Agreement

The paper presents the application of a coupling methodology between Computational Fluid Dynamics (CFD) and System Thermal Hydraulic (STH) codes developed at the University of Pisa. The methodology was applied to the CIRCE-HERO facility in order to reproduce the recently performed experimental conditions simulating a Protected Loss Of Flow Accident (PLOFA). The facility consists of an internal loop, equipped with a fuel pin simulator and a steam generator, and an external pool. In this coupling application, the System code RELAP5 is adopted for the simulation of the internal loop while the CFD code ANSYS Fluent is used for the sake of simulating the pool. The connection between the two addressed domains is provided at the inlet and outlet section of the internal loop; a thermal coupling is also performed in order to reproduce the observed thermal stratification phenomenon. The obtained results are promising and a good agreement was obtained for both the mass flow rates and temperature measurements. Capabilities and limitations of the adopted coupling technique are discussed in the present paper also providing suggestions for improvements and developments to be achieved in the frame of future applications.

CFD Analysis of the Primary Side in a Helical-Coil Once-Through Steam Generator

2017 ◽  
Author(s):  
Kai Ye ◽  
Yaoli Zhang ◽  
Jianshu Lin ◽  
Ning Li ◽  
Yinglin Yang ◽  
...  
Keyword(s):  
Steam Generator ◽  
Nuclear Power ◽  
Rational Design ◽  
Large Scale ◽  
Three Dimensional ◽  
Helical Coil ◽  
Complicated Structure ◽  
Ansys Fluent ◽  
Flow Parameters ◽  
Computational Fluid Dynamics Cfd

The helical-coil once-through steam generator (OTSG) is usually used in the nuclear power plant when the compactness of equipment was taken into consideration. The investigation of flow parameters in the primary side is valuable for the optimization of the OTSG. The purpose of this research is to obtain a further understanding of fluid behaviors in the primary side of the OTSG to achieve a more rational design. Using ANSYS ICEM and ANSYS FLUENT, a three-dimensional (3D) computational fluid dynamics (CFD) model was created and analyzed. Through a series of cases, the velocity profiles and pressure drop through the primary side of the helical-coil OTSG have been calculated, and the influences of different structure designs on the coolant flow parameters have also been tested. Ultimately some pertinent suggestions for improvements were proposed, and insight is obtained into the importance of various modeling considerations in such a model with a complicated structure and large-scale grids.

On the Performance of Swing Arm Flapping Turbines

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Benarfaoui Arfaoui ◽  
Mohamed Taher Bouzaher ◽  
Belhi Guerira ◽  
Charaf-Eddine Bensaci
Keyword(s):  
Turbine Blades ◽  
Ansys Fluent ◽  
Extraction Mechanism ◽  
Turbine Efficiency ◽  
Gurney Flap ◽  
Swing Arm ◽  
Suggested Strategy ◽  
Translation Motion ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

Abstract This study investigates the energy extraction mechanism by means of swing arm turbine. The swing arm turbines have a particular motion pattern. The pure translation motion in the conventional flapping turbine changes based on the swing arm rotation. The laminar flow around a NACA0015 is resolved using computational fluid dynamics (CFD) method. The turbine blades are equipped with an oscillating gurney flap for trying to boost the system efficiency. The connected gurney flap oscillates with a given pitching angle. A user-defined function and the sliding dynamic mesh technique available in ansys fluent version 15 are used to adjust both the blade and the flap positions during the turbine flapping cycle. The effects of the swing factor and the flap length on the system performance are provided. It is shown that the suggested strategy of control is able to alter the pressure distribution during both the up stroke and down stroke phases, which changes the blade aerodynamic forces during all the flapping cycle portions and therefore improving the turbine efficiency.

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