scholarly journals Analytical Solution for Heat Transfer in Electroosmotic Flow of a Carreau Fluid in a Wavy Microchannel

2019 ◽  
Vol 9 (20) ◽  
pp. 4359 ◽  
Author(s):  
Saima Noreen ◽  
Sadia Waheed ◽  
Abid Hussanan ◽  
Dianchen Lu

This article explores the heat and transport characteristics of electroosmotic flow augmented with peristaltic transport of incompressible Carreau fluid in a wavy microchannel. In order to determine the energy distribution, viscous dissipation is reckoned. Debye Hückel linearization and long wavelength assumptions are adopted. Resulting non-linear problem is analytically solved to examine the distribution and variation in velocity, temperature and volumetric flow rate within the Carreau fluid flow pattern through perturbation technique. This model is also suitable for a wide range of biological microfluidic applications and variation in velocity, temperature and volumetric flow rate within the Carreau fluid flow pattern.

2003 ◽  
Vol 807 ◽  
Author(s):  
L. Liu ◽  
I. Neretnieks

ABSTRACTIn this paper, we are concerned with a specific scenario where a large fracture intersects, at its center, a canister that contains spent nuclear fuel. Assuming that a nuclide is free to release from the canister into groundwater flowing through the fracture, a detailed formulation of the volumetric flow rate and the equivalent flow rate are made for the parallel plate model. The formulas proposed have been validated by numerical examinations; they are not only simple in forms but also universal in applications where the flow may be taken normal, inclined or parallel to the axis of the canister. Of great importance, they provide a convenient way to predict the average properties of fluid flow and solute transport through a single fracture with spatially variable apertures.


2019 ◽  
Vol 29 (3) ◽  
pp. 94
Author(s):  
Tamara Sh. Ahmed

During this article, we have a tendency to show the peristaltic activity of magnetohydrodynamics flow of carreau fluid with heat transfer influence in an inclined tapered asymmetric channel through porous medium by exploitation the influence of non-slip boundary conditions. The tapered asymmetric channel is often created because of the intrauterine fluid flow induced by myometrial contraction and it had been simulated by asymmetric peristaltic fluid flow in an exceedingly two dimensional infinite non uniform channel, this fluid is known as hereby carreau fluid, conjointly we are able to say that one amongst carreau's applications is that the blood flow within the body of human. Industrial field, silicon oil is an example of carreau fluid. By exploitation, the perturbation technique for little values of weissenberg number, the nonlinear governing equations in the two-dimensional Cartesian coordinate system is resolved under the assumptions of long wavelength and low Reynolds number. The expressions of stream function, temperature distribution, the coefficient of heat transfer, frictional forces at the walls of the channel, pressure gradient are calculated. The effectiveness of interesting parameters on the inflow has been colluded and studied.


2011 ◽  
Vol 467-469 ◽  
pp. 2013-2017
Author(s):  
Hsiang Chen Hsu ◽  
Hsi Chien Liu ◽  
Cheng Jiun Han

A microfluidic multi-cylindric rapid micromixer is fabricated in the present paper. The key features in the presented MEMS-based microchannel design are (1) micro pump (2) Y-junction type channel (3) cylindric obstacle (4) notch with the edge of sharp teeth. Two different fluids (DI water and red ink) were pumped and injected into Y-type channel, and the fluids were broken-up by a cylindric obstacle in the center of tapered microchannel. The chaotic convection occurs in the mixing channel behind the cylindric obstacle. The mixing index is defined to qualify the mixing efficiency, which demonstrates the outlet notch with sharp teeth along the sidewall plays an important role for mixing effects. The developed micromixer can enhance mixing using the mechanisms of diffusion and convection for wide range of Reynolds number (0.01<Re<100). Parametric studies for volumetric flow rate include the number of cylindric obstacles, the number of notches with sharp-teeth and the width of microchannel. Preliminary results demonstrate that the mixing index reaches the desired effect (<0.1) within 0.08 second when the inlet fluid velocity is 0.49992m/s, i.e. volumetric flow rate is 1200μl /min. The presented device is faster than most of reported micromixers.


Gases ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 156-179
Author(s):  
Abubakar Jibrin Abbas ◽  
Hossein Hassani ◽  
Martin Burby ◽  
Idoko Job John

As an alternative to the construction of new infrastructure, repurposing existing natural gas pipelines for hydrogen transportation has been identified as a low-cost strategy for substituting natural gas with hydrogen in the wake of the energy transition. In line with that, a 342 km, 36″ natural gas pipeline was used in this study to simulate some technical implications of delivering the same amount of energy with different blends of natural gas and hydrogen, and with 100% hydrogen. Preliminary findings from the study confirmed that a three-fold increase in volumetric flow rate would be required of hydrogen to deliver an equivalent amount of energy as natural gas. The effects of flowing hydrogen at this rate in an existing natural gas pipeline on two flow parameters (the compressibility factor and the velocity gradient) which are crucial to the safety of the pipeline were investigated. The compressibility factor behaviour revealed the presence of a wide range of values as the proportions of hydrogen and natural gas in the blends changed, signifying disparate flow behaviours and consequent varying flow challenges. The velocity profiles showed that hydrogen can be transported in natural gas pipelines via blending with natural gas by up to 40% of hydrogen in the blend without exceeding the erosional velocity limits of the pipeline. However, when the proportion of hydrogen reached 60%, the erosional velocity limit was reached at 290 km, so that beyond this distance, the pipeline would be subject to internal erosion. The use of compressor stations was shown to be effective in remedying this challenge. This study provides more insights into the volumetric and safety considerations of adopting existing natural gas pipelines for the transportation of hydrogen and blends of hydrogen and natural gas.


1975 ◽  
Vol 97 (3) ◽  
pp. 451-456 ◽  
Author(s):  
J. F. Kreider

The performance of a novel solar energy concentrating system consisting of a fixed, concave spherical mirror and a sun-tracking, cylindrical absorber is analyzed in detail. This concentrating system takes advantage of the spherical symmetry of the mirror and its linear image which, when taken together, form a tracking, solar-concentrating system in which only the small cylindrical absorber need move. The effects of mirror reflectance, concentration ratio, heat transfer fluid flow rate, radiative surface properties, incidence angle, an evacuated absorber envelope, and insolation level upon thermal performance of the concentrator are studied by means of a mathematical model. The simulation includes first order radiation and convection processes between the absorber and its concentric glass envelope and between the envelope and the environment; radiation processes are described by a dual-band, gray approximation. The energy equations are solved in finite difference form in order that heat flux and temperature distributions along the absorber may be computed accurately. The results of the study show that high-temperature heat energy can be collected efficiently over a wide range of useful operating conditions. The analysis indicates that mirror surface reflectance is the single most important of the principal governing parameters in determining system performance. Efficiency always increases with concentration ratio although the rate of increase is quite small for concentration ratios above 50. High fluid flow rate (i.e., lower operating temperature), an evacuated envelope, or a highly selective surface can enhance performance under some conditions. The conclusion of the study is that high-temperature heat energy can be generated at high efficiency by the present concentrator with present technology in sunny regions of the world.


2021 ◽  
Author(s):  
Sudad H Al-Obaidi

The stresses acting in the vicinity of wells have a significant impact on the flow properties of the reservoir and, as a result, on the flow rate of oil wells. The magnitude of such stresses depends on the deformation properties of the rock and on the oil pressure at the bottom of the well. In this work, an attempt to study the effect of flow fields (formation flow rate, well flow rates) on rocks in near-wellbore zones was performed. For this purpose, the correlation of such indicators as the fluid flow rate and the risk of destruction of the rocks of the productive deposits of one of the gas fields were experimentally studied. The experiments were performed on chosen core samples with quite wide range of flow and volumetric reservoir properties. It was concluded that the rock samples of the productive deposits of the studied formation do not collapse under the influence of pressure gradients corresponding to the design flow rates.


2006 ◽  
Vol 113 ◽  
pp. 603-608
Author(s):  
Riza Gürbüz

The purpose of this article is to design a mechatronics system to measure fluid friction losses in a specially designed fluid friction apparatus. It measured fluid flow rates by using venturi tube and orifice plate, and velocity of fluid is calculated in terms of flow rate and pipe diameter. Friction factor (K factor) of some valves and fittings such as tee, elbow, Y Junction, gate and globe valves and friction losses in pipe was measured in this system. It is one of the best methods to measure losses in pipes and fittings experimentally. It used a computer, data acquisition cards, pressure differential transmitters, venturi tube and orifice meter to measure the flow rate, pressure drops on flow rate measurement devices and pressure drops of some valves and fittings to be measured K factors. It also measured the temperature of fluid by using J type Thermocouple. A computer program is written to calculate the Reynold number of fluid, friction factor of pipe, velocity of fluid, frictional losses of fluid, flow rate and K factor of valves and fittings. Required data was received from measured quantities. The conclusion of experiments is shown in article. Volumetric flow rate range was determined 0-1 (L/s), while the pressure drop was 0-100 kPa in experiments.


2013 ◽  
Vol 135 (7) ◽  
Author(s):  
H. Stel ◽  
G. D. L. Amaral ◽  
C. O. R. Negrão ◽  
S. Chiva ◽  
V. Estevam ◽  
...  

This work presents a numerical investigation of the fluid flow in the first stage of a two-stage centrifugal pump with a vaned diffuser. A computational fluid dynamics (CFD) analysis is performed by using the ANSYS-CFX software for a wide range of volumetric flow rates and also for different rotor speeds. The numerical results are validated against measured values of pressure rise through the impeller and diffuser of the first stage with an overall good agreement. Nevertheless, not only the best efficiency point evaluated numerically is overestimated in comparison with the measured two-stage pump values but also the computed hydraulic efficiency of the first stage. Investigation of the flow pattern for different flow rates reveals that the flow becomes badly oriented for part-load conditions. In such cases, significant levels of turbulence and blade orientation effects are observed, mainly in the diffuser. In spite of different flow rates or rotor speeds, the flow pattern is quite similar if the flow dimensionless coefficient is kept constant, showing that classical similarity rules can be applied in this case. By using such rules, it was also possible to derive a single equation for the pump head to represent the whole operational range of the pump.


In this research paper, fluid flow is considered in uni direction through the multi – irregular constricted artery. Blood has been considered Hershcel –Bulkley i.e. non- Newtonion. Analytical techniques are carried out to solve the problem. Mathematical expressions for several variables of fluid flow has been estabilished. The effect of slip velocity, flow behaviour index and yield stress on axial velocity volumetric flow rate and wall shear stress have been depicted through graphs. It has noticed that velocity in axial direction and fluid flow rate increases as increase in slip velocity at arterial wall. It has also observed that shear stress increases with increasing of yield stress. Flow rate reaches lowest value at some points in the portion of stenosis for clinical investigation.


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