Numerical Study of the inside Flow Field and the Rectangle Channel Impeller of Roto-Jet Pump

2014 ◽  
Vol 529 ◽  
pp. 164-168 ◽  
Author(s):  
Wei Zang ◽  
Xin Cheng Li ◽  
Yi Chen ◽  
Yu Ting Luo
Keyword(s):  
Flow Field ◽  
Numerical Simulations ◽  
Numerical Study ◽  
The Other ◽  
Jet Pump ◽  
Hydraulic Models ◽  
Flow Channels ◽  
Ansys Cfx ◽  
Angle Blade

By means of ANSYS-CFX, the 3D numerical simulations of flow field for the three hydraulic models are performed. Through comparing the three types of pumps with three different rectangle channel impellers which have different spread angle, blade, the authors draw conclusions: the distribution of the pressure and velocity in the rectangle flow channels with 6° spread angle is well-proportioned, the head and the efficiency of the whole pump can meet the requirement: But the other two types of impeller channels, the distribution of velocity is unstable, there are backflow and big whirlpool. Therefore, the rectangle channel impeller with 6°spread angle is a better type for the Roto-Jet pump.

Improved Thermal Uniformity by Introducing Tree-Like Flowing Channels in a PEMFC Flow-Field Plate

2017 ◽  
Author(s):  
Yuxin Jia ◽  
Rui Zhu ◽  
Bengt Sunden ◽  
Gongnan Xie
Keyword(s):  
Fuel Cells ◽  
Flow Field ◽  
Proton Exchange Membrane ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Flow Channel ◽  
Proton Exchange ◽  
Field Plate ◽  
Flow Channels ◽  
Exchange Membrane

Thermal uniformity in the flow field plate of proton exchange membrane fuel cells (PEMFCs) is crucial for their power generating efficiency and reliability and therefore, has attracted much attention. The present numerical study is an attempt to optimize the flow channels via replacement of convectional zigzag continuous channels by tree-like bifurcated channels radially outwards. The numerical model is validated by experimental data available in the open literature. The effects of included angles and length ratios among the channels on thermal uniformity are analyzed based on detailed fluid flow characteristics. Results show that tree-like channels outperform conventional ones. It is found that tree-like flow channels can improve thermal uniformity of proton exchange membrane fuel cells. Within limits, with smaller angle between bifurcated flow channels and length ratio 2−1/3 between higher flow channel and lower flow channel, PEMFC can obtain the most uniform temperature distribution in Y shape tree-liked flow field.

scholarly journals Numerical Investigation of the Flow Field and Mass Transfer Characteristics in a Jet Slurry Pump

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 2053
Author(s):  
Yi’nan Qian ◽  
Yuanshun Wang ◽  
Zhenlong Fang ◽  
Xiuhan Chen ◽  
Sape A. Miedema
Keyword(s):  
Flow Field ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Internal Flow ◽  
Axial Line ◽  
Suction Pressure ◽  
Flow Ratio ◽  
Jet Pump ◽  
Mixing Chamber

A jet pump is used to transport a variety of working media and is especially suitable for dredged soil transporting. In this study, a three-dimensional numerical study of a jet pump that is used for slurry delivery was carried out. The characteristics of the internal flow field of the mixing chamber with different working parameters were comprehensively analyzed. The results indicate that the pressure of the axial line decreases with increasing flow ratio (ratio of suction flux and inlet flux) while the pressure of the injected slurry shows a downward trend. With the increase in the flow ratio, the pressure ratio (difference between inlet pressure and suction pressure divided by the difference between exit pressure and suction pressure) falls off while the efficiency presents a parabolic distribution. The pressure ratio can be promoted by properly increasing the length of the mixing chamber so that the available efficiency is broadened. When the mixing chamber length is L = 2.5Dn~4.0Dn (Dn is nozzle outlet diameter), the highly efficient area is wide; in particular, when L = 3.5Dn, the jet slurry pump with the highest efficiency of 27.6% has the best performance.

Aerodynamic Design Optimization of Elliptical-Bladed Savonius-Style Wind Turbine by Numerical Simulations

2016 ◽  
Author(s):  
Nur Alom ◽  
Satish Chandra Kolaparthi ◽  
Sarath Chandra Gadde ◽  
Ujjwal K. Saha
Keyword(s):  
Flow Field ◽  
Numerical Simulations ◽  
Wind Turbine ◽  
Numerical Study ◽  
Low Cost ◽  
Vertical Axis ◽  
3D Simulation ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine

Savonius-style wind turbine (SSWT), a class of vertical-axis wind turbine, appears to be promising for off-shore applications because of its design simplicity, good starting ability, insensitivity to wind direction, relatively low operating speed, low cost and easy installation. Various blade shapes have been used over the years to improve the performance of this class of turbine. In the recent past, an elliptic-bladed profile with sectional cut angle of 50° has shown its potential to harness the wind energy more efficiently. The present study aims to optimize this profile by numerical simulations. In view of this, the elliptical-bladed profiles are tested at different sectional cut angles of θ = 45°, 47.5°, 50° and 55°. The shear stress transport (SST) k-ω turbulence model is used to simulate the flow field, and thereafter, the torque and power coefficients are obtained at the rotating conditions. From 2D simulation, pressure and velocity contours are generated and analyzed. 2D simulations are also carried out for a semi-circular bladed profile in order to have a direct comparison. The numerical study demonstrates an improved flow characteristics, and hence the power coefficient of the elliptical-bladed profile at = 47.5°. Finally, 3D simulation is carried out to visualize and analyze the flow field around the optimum elliptical-bladed rotor at a tip speed ratio of 0.8. The aspect ratio of the rotor for the 3D simulation is kept at 0.7.

Numerical Study of Flow Through 3x3 Multiswirler Arrays With Co and Counter Swirler Arrangements

2015 ◽  
Author(s):  
Prachi Rojatkar ◽  
Milind A. Jog ◽  
San-Mou Jeng
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
Turbulence Model ◽  
Velocity Gradient ◽  
Recirculation Zone ◽  
Numerical Study ◽  
The Other ◽  
Combustion Performance ◽  
Other Hand ◽  
Flow Through

A numerical study of turbulent flow through 3×3 multi swirler arrangement has been performed using the realizable k-ε turbulence model on a grid with about 19 million points. All co and alternate co/counter swirler configurations comprised of radial-radial swirler with counter rotating vanes are analyzed. The offset distances of swirler exit from the base wall of confinement of 0.02D and 0.31D are considered where D is the diameter of swirler exit. For both arrangements, a strong jet is issued as the flow exits individual swirl cup. Recirculation is observed at the walls and between each swirl cup along with the formation of central toroidal recirculation zone (CTRZ) at each individual swirler. It is observed that all co swirling arrangement has a stronger more compact individual CTRZ. On the other hand alternate co and counter arrangement produces more swirler-to-swirler interactions. When the offset between swirler exit and base wall of confinement is increased to 0.31D, longer but more compact CTRZ are formed at each swirler cup. The velocity gradient for 0.31D offset case is also higher than that of 0.02D. These differences in the flow field indicate better combustion performance, fuel breakup and flame anchoring for the higher offset case.

scholarly journals Numerical Study on the Working Performance of a Streamlined Annular Jet Pump

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4411
Author(s):  
Xiaodong Wang ◽  
Yunliang Chen ◽  
Mengqiu Li ◽  
Yong Xu ◽  
Bo Wang ◽  
...  
Keyword(s):  
Flow Field ◽  
High Efficiency ◽  
Numerical Study ◽  
Flow Ratio ◽  
Jet Pump ◽  
Local Pressure ◽  
Maximum Increase ◽  
Annular Jet ◽  
Working Performance ◽  
Annular Jet Pump

To improve the working performance of the early annular jet pump (EAJP), a streamlined annular jet pump (SAJP) was proposed. The flow field and working performance of the EAJP and SAJP with an area ratio (m) of 1.75 were numerically studied and compared, separately, by using the combination of the Realizable k-ε turbulence model and the Schnerr–Sauer cavitation model. The results show that the efficiency of the SAJP is higher than that of the EAJP, when the flow ratio (q) is higher than 0.30, with a maximum increase of 1.2%. Furthermore, the high-efficiency area of the SAJP (q = 0.40~0.69) is wider than that of the EAJP (q = 0.36~0.57). There is no flow separation and low local pressure in the SAJP, due to the conjunction part of the suction chamber, throat, diffuser and outlet pipe without the structural mutation. It was found that the incipient cavitation number (σi) of the SAJP and EAJP was 0.541 and 0.578, respectively; therefore, the cavitation performance of the SAJP is better. Meanwhile, the critical flow ratio (qc) of the SAJP is 0.69, which is larger than that of the EAJP (qc = 0.57), implying that the SAJP has a wider normal working range than the EAJP. Importantly, the inception and development of cavitation appeared in the diffuser of the SAJP, different from that in the throat of the EAJP. Hence, it concluded that the cavitation in the SAJP has less influence on the flow field and working performance.

Experimental and Numerical Investigation of the DrivAer Model

2012 ◽  
Author(s):  
Angelina I. Heft ◽  
Thomas Indinger ◽  
Nikolaus A. Adams
Keyword(s):  
Flow Field ◽  
Numerical Simulations ◽  
Open Source ◽  
Numerical Investigation ◽  
Open Source Software ◽  
The Other ◽  
Interference Effects ◽  
Aerodynamic Optimization ◽  
Car Model ◽  
High Degree

Automotive aerodynamic research often focuses on strongly simplified car models, such as the Ahmed body and the SAE model. Due to their high degree of abstraction, however, interference effects are often neglected which leads to an unrealistic representation of the flow field. Consequently, these results cannot be directly used for the aerodynamic optimization of production vehicles. On the other hand, aerodynamic investigations of real production vehicles are often limited due to the restricted availability of the geometric data. Therefore, a new realistic generic car model for aerodynamic research — the DrivAer body — is proposed. This paper focuses on the development of the model, summarizes first experimental results of the different configurations of the fastback geometry and compares them to numerical simulations performed using the open source software OpenFOAM®.

A comprehensive numerical study of battle damage and repairs upon the aerodynamic characteristics of an aerofoil

2010 ◽  
Vol 114 (1158) ◽  
pp. 469-484 ◽  
Author(s):  
M. Saeedi ◽  
F. Ajalli ◽  
M. Mani
Keyword(s):  
Flow Field ◽  
Numerical Solution ◽  
Mesh Generation ◽  
Unstructured Mesh ◽  
Numerical Study ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Experimental Results ◽  
The Other ◽  
Stall Angle

Abstract A NACA 641-412 aerofoil with circle and star damage and also three repair configurations has been numerically investigated. Two different methods of mesh generation were employed: multi structured mesh for the star damaged aerofoil and unstructured mesh for the other aerofoils. The results show that the damage will cause a reduction in lift coefficient of the aerofoil and also a different stall angle relative to that of the undamaged aerofoil. Each kind of repair improves the aerodynamic characteristics of the aerofoil considerably. The flow Field inside the damage hole and the cavity caused by the repair sheets was also investigated. Finally, the numerical solution was qualitatively and quantitatively validated using the available experimental results.

Numerical Study of the Combined Free-Forced Convection and Mass Transfer Flow Past a Vertical Porous Plate in a Porous Medium with Heat Generation and Thermal Diffusion

2006 ◽  
Vol 11 (4) ◽  
pp. 331-343 ◽  
Author(s):  
M. S. Alam ◽  
M. M. Rahman ◽  
M. A. Samad
Keyword(s):  
Mass Transfer ◽  
Flow Field ◽  
Differential Equations ◽  
Forced Convection ◽  
Heat Generation ◽  
Numerical Study ◽  
Porous Plate ◽  
Integration Scheme ◽  
Suction Parameter ◽  
Transfer Flow

The problem of combined free-forced convection and mass transfer flow over a vertical porous flat plate, in presence of heat generation and thermaldiffusion, is studied numerically. The non-linear partial differential equations and their boundary conditions, describing the problem under consideration, are transformed into a system of ordinary differential equations by using usual similarity transformations. This system is solved numerically by applying Nachtsheim-Swigert shooting iteration technique together with Runge-Kutta sixth order integration scheme. The effects of suction parameter, heat generation parameter and Soret number are examined on the flow field of a hydrogen-air mixture as a non-chemical reacting fluid pair. The analysis of the obtained results showed that the flow field is significantly influenced by these parameters.

Using Ansys for Design and Numerical Study of a Specific Fixed Wing UAV

2018 ◽  
Vol 55 (4) ◽  
pp. 652-657 ◽  
Author(s):  
Gabriel Murariu ◽  
Razvan Adrian Mahu ◽  
Adrian Gabriel Murariu ◽  
Mihai Daniel Dragu ◽  
Lucian P. Georgescu ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Unmanned Aerial Vehicle ◽  
Numerical Study ◽  
Flight Time ◽  
Cluster System ◽  
Numerical Results ◽  
Operational Performance ◽  
Gliding Flight ◽  
Aerial Vehicle ◽  
Constant Altitude

This article presents the design of a specific unmanned aerial vehicle UAV prototype own building. Our UAV is a flying wing type and is able to take off with a little boost. This system happily combines some major advantages taken from planes namely the ability to fly horizontal, at a constant altitude and of course, the great advantage of a long flight-time. The aerodynamic models presented in this paper are optimized to improve the operational performance of this aerial vehicle, especially in terms of stability and the possibility of a long gliding flight-time. Both aspects are very important for the increasing of the goals� efficiency and for the getting work jobs. The presented simulations were obtained using ANSYS 13 installed on our university� cluster system. In a next step the numerical results will be compared with those during experimental flights. This paper presents the main results obtained from numerical simulations and the obtained magnitudes of the main flight coefficients.

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