CFD Analysis Of Flow Research Articles

Computational domain discretization for CFD analysis of flow in a granular packed bed

Computational domain discretization is the pre-processing stage in CFD analysis and it highly contributes to the solution error as well as the numerical stability of a model. The discretization of domain representing a packed bed of granular material is a demanding task due to the topology of the model consisting of spherical granules contacting tangentially. Therefore the aim of the research is to define guidelines to effectively discretize the computational domain representing the packed bed of granular material, validate it using Particle Image Velocimetry (PIV) and evaluate the impact of variable inflow velocity on the experimental and numerical research results.

Thermodynamic performance of a CO2 vortex tube based on 3D CFD flow analysis

The vortex tube (VT) is a mechanical device that can simultaneously provide heating and cooling. In this work, a 3D CFD model is first developed to simulate the flow of CO2 within a vortex tube, and then it is validated with published experimental data. The assumed k-ε turbulence model uses Structured Hexahedral nodes generated in ANSYS Meshing. Only 1/6 of the geometry is required due to the symmetry of the VT. The validated CFD model is combined with a thermodynamic model of the VT to complete a parametric study, where the inlet pressure (550 kPa to 1300 kPa) and cold mass fraction (0.2–0.9) are the chosen parameters. The effects on the VT energy separation and performance are presented. Energy separation is discussed in terms of the hot exit and cold exit temperature differences, both with respect to the VT inlet temperature. Performance is characterized by cooling power, heating power, and both energy and exergy metrics. The numerical results show that the variation of the cold mass fraction from 0.2 to 0.9, for a fixed inlet pressure of 1300 kPa, causes the hot exit temperature difference to rise from 10 °C to 78.9 °C, while the cold exit temperature difference falls from 44.2 °C to 9.7 °C.

CFD Analysis of Flow and Performance Characteristics of a 90°curved Rectangular Diffuser: Effects of Aspect Ratio and Reynolds Number

Abstract The effect of aspect ratio (AS = 0.5, 1.0, 2.0) and Reynolds number (Re = 1, 2, 4, 8 × 105) on the flow and performance characteristics of a 90° curved rectangular diffuser was examined with the aid of the commercial CFD code ANSYS FLUENT. The results from computational analysis revealed the presence of stream vorticity indicative of secondary flow brought about by the curvature of the diffusing duct. As the fluid flow developed, the inertial core flow was pushed to the outer concave wall by overbearing centrifugal forces. The fluid flow sustained marginal changes with increasing aspect ratio and Reynolds number. However, the flow uniformity at the exit was enhanced. The rise in coefficient of static pressure (Cp) recovery and the drop in coefficient of total pressure loss (Closs) with increasing Reynolds number suggested improved diffuser performance. The flow uniformity index was found to be the highest for the diffuser of aspect ratio 1.

CFD Analysis of Flow Over Bluff Bodies with Various Ranges of Injection using ANSYS CFX

CFD Analysis of Flow Over Bluff Bodies with Various Ranges of Injection using ANSYS CFX

Two-Phase Flow CFD Analysis of Temperature Effects on Oil Supplied to Small-Bore Journal Bearing with Oil Supply Groove

Two-Phase Flow CFD Analysis of Temperature Effects on Oil Supplied to Small-Bore Journal Bearing with Oil Supply Groove

Design and Fabrication of Water Pressure Nozzle by Using CFD Flow Analysis

Design and Fabrication of Water Pressure Nozzle by Using CFD Flow Analysis

Elliptical Shape Hole-Pattern Seals Performance Evaluation Using Design of Experiments Technique1

Hole-pattern annular gas seals have two distinct flow regions: an annular jet-flow region between the rotor and stator, and cylindrical indentions in the stator that serve as cavities where flow recirculation occurs. As the working fluid enters the cavities and recirculates, its kinetic energy is reduced, resulting in a reduction of leakage flow rate through the seal. The geometry of the cylindrical cavities has a significant effect on the overall performance of the seal. In this study, the effects of elliptical shape hole pattern geometry on the leakage and dynamic response performance of an industry-relevant hole-pattern seal design are investigated using a combination of computational fluid dynamics (CFD), hybrid bulk flow-CFD analysis, and design of experiments (DOEs) technique. The design space was defined by varying the values of five geometrical characteristics: the major and minor radius of hole, the angle between the major axis and the axis of the seal, the spacing between holes along the seal axis, and hole spacing in the circumferential direction. This detailed analysis allowed for a greater understanding of the interaction effects from varying all of these design parameters together as opposed to studying them one variable at a time. Response maps generated from the calculated results demonstrate the effects of each design parameter on seal leakage as well as the co-dependence between the design parameters. The data from this analysis were also used to generate linear regression models that demonstrate how these parameters affect the leakage rate and the dynamic coefficients, including the effective damping.

CFD analysis of flow around a catheter in peripheral vein and thrombus formation in it

CFD analysis of flow around a catheter in peripheral vein and thrombus formation in it

Modeling and CFD Analysis of Flow Over Aircraft Split Winglet and Blended Winglet

Modeling and CFD Analysis of Flow Over Aircraft Split Winglet and Blended Winglet

低放射・集中排気型厨房機器を用いた業務用厨房の空気・温熱環境に関する研究 （その13）空調吹出し気流下のフード周辺気流のCFD解析

低放射・集中排気型厨房機器を用いた業務用厨房の空気・温熱環境に関する研究 （その13）空調吹出し気流下のフード周辺気流のCFD解析

空調設備におけるCFDを用いた流体音解析に関する研究 (第1報）CFDによる分岐管・合流管の流れ解析

空調設備におけるCFDを用いた流体音解析に関する研究 (第1報）CFDによる分岐管・合流管の流れ解析

CFD Flow Analysis and Optimization of Exhaust Muffler

CFD Flow Analysis and Optimization of Exhaust Muffler

Design and Performance Analysis of a CD Nozzle for Evacuating Emissions from the Subway Tunnels

Tunnels have very severe air quality constraints that typically require good ventilation system. The process of removing air from any space by mechanical means is known as evacuation. Evacuation of exhaust and smoke in case of fire emergencies is very necessary to bring in fresh air as it leads to pressure and temperature build up which causes discomfort to the passengers travelling especially in long tunnels. Generally, in longitudinal ventilation, a jet blower fan enclosed in a cylindrical casing is used for ventilation. These jet fans accelerate the air by imparting it an impulse in the desired direction. The main aim is to optimize the design and replace the jet blower fan cylindrical enclosure by a CD Nozzle. The suction fan along with rotor is exactly placed at the throat of the nozzle. The modeling is done using CATIA V5 software and CFD flow and modal analysis is carried out using ANSYS V 15.0. Various parameters like pressure, temperature, density, humidity and mass flow rate of air are measured and compared with the conventional model by experimentation and the results are validated.

Flow CFD Analysis of 2D Transient Melt flow from crucible on to the rotating wheel in Planar Melt Spinning Process

Transient Flow numerical analysis in planar flow melt spinning process hasbeen carried out by several investigators considering uniform melt flow velocityexiting the nozzle slit on to the rotating wheel. The present numerical simulations studies the molten metal flow originating from the crucible, flowingthrough the nozzle slit, and making a 900 turn onto the rotating wheel. This renders the melt flow velocity exiting the nozzle slit to be non-uniform and parabolic in nature which is a more realistic representation of the actual flow. Inert gas present above the molten metal (Fe-B-Si)to prevent oxidation and push the melt out was simulated for pressures ranging from 2 to 6 psig. A Volume of Fluid (VOF) model has been developed in ANSYS Fluent to understand the effects of various process parameters influencing puddle length and amorphous strip formation such as:inert gas ejection pressure, nozzle contact angle θnozzle,and melt temperature. Conjugate heat transfer between the melt puddle and rotating wheel is investigatedas the wheel temperature does not remain constantduring an actual PFMS process. This causes the puddle length to increase and also a consequent decrease in the ribbon thickness which is in agreement with experimental data.

CFD Analysis of Nanorefrigerant through Adiabatic Capillary Tube of Vapour Compression Refrigeration System

Over time attempts have been made to understand the flow characteristics of refrigerants through capillary tubes as well as to seek more thermally efficient working fluids for refrigeration systems. This study investigated the flow of nanorefrigerants through adiabatic capillary tubes of vapour compression refrigeration systems; and afterwards creates numerical models that will account for solution of refrigerant side pressure drop and mass flow rate. Also in this study, a CFD flow analysis was carried out using a CFD simulation/solver such that the results of the simulations obtained were discussed so as to establish a distinction between the conventional and nano-refrigerants. Upon comparison of the CFD results of nanorefrigerants (CuR134a, CuR600a) and the conventional refrigerants (R134a, R600a), the conventional refrigerants were noticed to have more isothermal regions implying that heat was not being transferred quickly enough to raise the temperature of the adjoining region thus proving that the addition of nanoparticles improves the thermophysical properties of the base fluid. Also, based on the results of the study of the flow patterns of both working fluids, the density of pressure contours in the conventional refrigerants was far larger than that of the nanorefrigerant implying that more compressor work and ultimately greater power will be required. The findings from this study were validated with experimental results showing that a CFD analysis tool/method can be employed to understudy the phenomenal changes that take place in nano-refrigerant movement through capillary tubes without recourse to experimentation.

CFD Analysis of Flow and Heat Transfer in Solar Air Heater Duct by using V-Shaped Inclined Continuous Ribs on Absorber Plate

CFD Analysis of Flow and Heat Transfer in Solar Air Heater Duct by using V-Shaped Inclined Continuous Ribs on Absorber Plate

Estimation of Flow Field & Drag for AerofoilWing

Investigation of airflow field over aerofoil wing is very essential to understand the flow complexity and its behaviour. In order to reduce the drag forces to achieve better performance with less power consumption for NACA 2415 model is been selected which is newly developed aerofoil wing. Drag force’s are very critical parameters to optimize the performance for various AOA’s. To understand flow complexity and how to reduce the fluid force parameters with the help of vortex generator kind of devices. Vortex Generators are highly efficient aerodynamic devices that are used widely in both external and internal aerodynamics as means of flow control. The paper deals with the CFD analysis of flow over wing at different flow regimes and as well different AOA’s without & VGs are placed on a wing. Complete three dimensional results are for the flow over wing equipped with Vortex Generators with various shapes and locations over the wing. The drag and lift characteristics of each shape and locations of VG’s have to be studied. The analyses has carried out for subsonic (M=0.5), transonic (M=1.0) and supersonic (M=2.0) flow regimes. The best shape and location of the VG’s for each of the flow regimes will be determined. All computations will be carried out using the RANS modelling which is available in commercially CFD package.

Design and Optimization of SUAV Empennage

Now a days the use of unmanned aerial vehicle (UAV) is getting common, as its size varies from small to large, which has good parameters like, light weight and good stability and can be used for surveillance, agriculture, and in defense as it can be controlled from ground or from other aircraft. In an UAV wing is blended with fuselage which gives lift to the UAV and the tail is also used for take-off and landing which is also gives higher stability to aircraft. It is important to design an empennage structure at lower drag and for good stability characteristics. In this present project airfoil coordinates has been generated by using JAVAFOIL, in this project NACA0010 airfoil is created, which is imported to CATIA V5 to design different empennage configurations of same wetted area and UAV empennage has been finally designed in a modeling tool CATIA V5 R19.The model is imported to Ansys through IGES file to simulate CFD analysis, where for analyzing fine meshing is taken for the whole structure of UAV and further CFD flow analysis is done through Ansys CFX software. The results for CL, CD and L/D are obtained by varying AOA with different velocity as shown in graphs (fig 13 to 18). A comparison is made for these empennages to check the aerodynamic efficiency and stability created by the different SUAV tails.

CFD analysis of flow and heat transfer in Canadian supercritical water reactor bundle

Within the Gen-IV International Forum, AECL is leading the effort in developing a conceptual design for the Canadian SCWR. AECL proposed a new fuel bundle design with two rings of fuel elements placed between central flow tube and the pressure tube. In line with the scope of the conceptual design, the objective of the present CFD work is to aid in developing a bundle heat transfer correlation for the Canadian SCWR fuel bundle design. This paper presents results from an ongoing effort in determining the conditions favorable for occurrence of HTD in the supercritical bundle flows. In the current investigation, bare-rod bundle geometry was tested for the proposed fuel bundle design at 23.5, 25 and 28MPa using STAR-CCM+ CFD code. Taking advantage of the design symmetry of the fuel bundle, only 1/32 of the computational domain was simulated. The low-Reynolds number modification of SST k–ω turbulence model along with y+<1 was used in the simulations. For lower mass flow simulations, the increase of inlet temperature and operational pressure was found effective in reducing the occurrence of HTD. For higher mass flow simulations, normal heat transfer behaviour was observed except for the lower pressure range (23.5MPa).

A study on rotational augmentation using CFD analysis of flow in the inboard region of the MEXICO rotor blades

AbstractThis work presents an analysis of data from existing as well as new full‐rotor computational fluid dynamics computations on the MEXICO rotor, with focus on the flow around the inboard parts of the blades. The boundary layer separation characteristics on the airfoil sections in the inboard parts of the rotor are analysed using the pressure and the skin friction data at a range of angles of attack. These data are used to gain insight on the relative behaviour of separated boundary layers in 3D flow compared with 2D flow. It has been found that separation on airfoils in rotating flows is different from that in 2D flows in two respects: (i) there is a chord‐wise postponement (or delay) of the separation point, and (ii) the angle of attack at which separation is initiated is higher in 3D compared with 2D. Comments are made on the mechanism of stall delay, and the main differences between the skin friction and pressure distribution behaviours in 2D and 3D rotating flows are highlighted. Copyright © 2014 John Wiley &amp; Sons, Ltd.