Effects of Rotation and Curvature Ratio on Fluid Flow and Energy Distribution through a Rotating Curved Rectangular Channel

2021 ◽  
Vol 30 (2) ◽  
pp. 243-269
Author(s):  
R. K. Chanda ◽  
M. S. Hasan ◽  
G. Lorenzini ◽  
R. N. Mondal
2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Yan Wang ◽  
Quanlin Dong ◽  
Pengfei Wang

In order to understand the mechanism of fluid flows in curved pipes, a large number of theoretical and experimental researches have been performed. As a critical parameter of curved pipe, the curvature ratioδhas received much attention, but most of the values ofδare very small (δ<0.1) or relatively small (δ≤0.5). As a preliminary study and simulation this research studied the fluid flow in a 90-degree curved pipe of large curvature ratio. The Detached Eddy Simulation (DES) turbulence model was employed to investigate the fluid flows at the Reynolds number range from 5000 to 20000. After validation of the numerical strategy, the pressure and velocity distribution, pressure drop, fluid flow, and secondary flow along the curved pipe were illustrated. The results show that the fluid flow in a curved pipe with large curvature ratio seems to be unlike that in a curved pipe with small curvature ratio. Large curvature ratio makes the internal flow more complicated; thus, the flow patterns, the separation region, and the oscillatory flow are different.


Author(s):  
Sophie Loire ◽  
Igor Mezic

Joint effect of traveling wave dielectrophoresis and AC electroosmotic fluid flow is used to sort bacteria from other particles and increase the bacteria output concentration in a microfluidic device. The device consists of a thin and long rectangular channel with two interdigitated electrode arrays, one at the bottom and one at the top of the channel, that are used to generate a nonuniform electric field. A four-phase signal at high frequency superposed on a low frequency signal is applied. At the end of the channel, the fluid is collected in two outputs: the bacteria are collected on one side and fluid without bacteria is collected on the other side. We have previously demonstrated a method to optimize cell separation using multiple frequency dielectrophoresis. The device presented here illustrates a novel use of multiple frequencies that permits the combined use of traveling wave dielectrophoresis and AC electroosmotic fluid flow.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ilyas Khan ◽  
Abid A. Memon ◽  
M. Asif Memon ◽  
Kaleemullah Bhatti ◽  
Gul M. Shaikh ◽  
...  

This article aims to study Newtonian fluid flow modeling and simulation through a rectangular channel embedded in a semicircular cylinder with the range of Reynolds number from 100 to 1500. The fluid is considered as laminar and Newtonian, and the problem is time independent. A numerical procedure of finite element’s least Square technique is implemented through COMSOL multiphysics 5.4. The problem is validated through asymptotic solution governed through the screen boundary condition. The vortex length of the recirculating region formed at the back of the cylinder and orientation of velocity field and pressure will be discussed by three horizontal and four vertical lines along the recirculating region in terms of Reynolds number. It was found that the two vortices of unequal size have appeared and the lengths of these vortices are increased with the increase Reynolds number. Also, the empirical equations through the linear regression procedure were determined for those vortices. The orientation of the velocity magnitude as well as pressure along the lines passing through the center of upper and lower vortices are the same.


2009 ◽  
Vol 131 (10) ◽  
Author(s):  
A. K. Majumder

Accurate knowledge of the fluid flow depth over an inclined rectangular open channel is of obvious value in the modeling of flow characteristics over that channel. Understanding of this type of fluid flow behavior is of immense importance to the mineral processing fraternity as a large number of separators work on this principle. Therefore, a multiple point computer-controlled depth gauge was developed to measure water flow depths at various flow rates ranging from 0.81 l/s to 2.26 l/s over an inclined (17.5 deg) rectangular channel (2400 mm long and 370 mm wide). This paper describes the details about the device and the data acquisition procedure. An attempt has also been made to predict the measured flow depths at various operating conditions by using a modified form of the conventional law of the wall model. An overall relative error of 4.23% between the measured and the predicted flow depths at various flow rates establishes the validity of the model.


2014 ◽  
Vol 1082 ◽  
pp. 327-331
Author(s):  
Thiago Antonini Alves ◽  
Murilo A. Barbur ◽  
Felipe Baptista Nishida

In this research, a study of the heat transfer enhancement in electronic components mounted in channels was conducted by using different materials in the conductive substrate. In this context, a numerical analysis was performed to investigate the cooling of 3D protruding heaters mounted on the bottom wall (substrate) of a horizontal rectangular channel using the ANSYS/FluentTM 15.0 software. Three different materials of the conductive substrate were analyzed, polymethyl methacrylate (PMMA), fiberglass reinforced epoxy laminate (FR4), and pure aluminum (Al). Uniform heat generation rate was considered for the protruding heaters and the cooling process happened through a steady laminar airflow, with constant properties. The fluid flow velocity and temperature profiles were uniform at the channel entrance. For the adiabatic substrate, the cooling process occurred exclusively by forced convection. For the conductive substrate, the cooling process was characterized by conjugate forced convection-conduction heat transfer through two mechanisms; one directly between the heaters surfaces and the flow by forced convection, and the other through conduction at the interfaces heater-substrate in addition to forced convection from the substrate to the fluid flow at the substrate surface. The governing equations and boundary conditions were numerically solved through a coupled procedure using the Control Volumes Method in a single domain comprising the solid and fluid regions. Commonly used properties in cooling of electronics components mounted in a PCB and typical geometry dimensions were utilized in the results acquisition. Some examples were presented, indicating the dependence of the substrate thermal conductivity related to the Reynolds number on the heat transfer enhancement. Thus, resulting in a lower work temperature at the electronic components.


2004 ◽  
Vol 2004 (0) ◽  
pp. 89-90
Author(s):  
Satoshi ANMA ◽  
Isao ISHIHARA ◽  
Ryosuke MATSUMOTO ◽  
Tomomasa UEMURA ◽  
Yasuhumi YAMAMOTO

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