scholarly journals MHD Peristaltic Transport of a Dusty Couple Stress Fluid Through a Symmetric Porous Channel

2018 ◽  
Vol 7 (4.10) ◽  
pp. 306
Author(s):  
E. P. Siva ◽  
`J. Prakash ◽  
A. Govindarajan ◽  
M. Vidhya
Keyword(s):  
Velocity Profile ◽  
Pressure Gradient ◽  
Skin Friction ◽  
Flow Rate ◽  
Analytical Solutions ◽  
Axial Velocity ◽  
Couple Stress ◽  
Perturbation Technique ◽  
Velocity Profiles ◽  
Permeability Parameter

This paper agreement with the MHD peristalsis flow of a dusty couple stress liquid in a 2-D channel. Analytical solutions are got for pressure gradient and axial velocity in the fluid using perturbation technique. The results obtained for velocity profile, pressure gradient and skin friction are graphically represented. It is noted the velocity profiles increases with the increase in time averaged flow rate (Q). The velocity profiles reduce with the raise in couple stress parameter (S) and Permeability parameter (k). 

EFFECT OF MAGNETIC FIELD ON PERISTALTIC TRANSPORT OF COUPLE STRESS FLUIDS THROUGH A POROUS MEDIUM

2011 ◽  
Vol 19 (02) ◽  
pp. 251-262 ◽  
Author(s):  
S. K. PANDEY ◽  
M. K. CHAUBE
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Axial Velocity ◽  
Couple Stress ◽  
Magnetic Parameter ◽  
Amplitude Ratio ◽  
Perturbation Technique ◽  
Mean Velocity ◽  
Stress Parameter ◽  
Permeability Parameter

This paper analyses peristaltic flow of a couple stress fluid in a channel through a porous medium in the presence of an external magnetic field. The flow is induced by sinusoidal traveling waves along the walls of the channel. The nonlinear convective acceleration terms are duly considered and a perturbation technique is used to solve the problem for the case of small amplitude ratio. The effects of couple-stress parameter, magnetic parameter and permeability parameter on mean velocity on the channel walls, mean axial velocity and critical reflux condition are discussed in detail. Computational results show that the mean velocity at the boundary decreases with increasing couple stress parameter and permeability parameter while it increases with magnetic parameter. It is also revealed that mean axial velocity decreases with increasing couple stress parameter and magnetic parameter while it increases with permeability parameter.

scholarly journals Analysis of dynamics variation against thixotropic parameter’s preferential range

2018 ◽  
Vol 45 (2) ◽  
pp. 231-251
Author(s):  
Nazish Shahid
Keyword(s):  
Shear Stress ◽  
Pressure Gradient ◽  
Flow Rate ◽  
Axial Velocity ◽  
Fluid Model ◽  
Current Model ◽  
Velocity Shear ◽  
Structural Parameter ◽  
Velocity Flow ◽  
Analysis Of Dynamics

Variation in the dynamics of a steady-state blood flow through a stenosed tapered artery has been investigated corresponding to changes in thixotropic parameter ? over the range [0,1]. To probe the role of parameter ? and differentiate the current model from other known non-Newtonian models, expressions of axial velocity, shear stress, wall shear stress and flow rate have been calculated depending upon this parameter and pressure gradient. Also, pressure gradient has been deduced uniquely with the help of the continuity equation. Our choice of calculating pressure gradient has led to obtaining shear stress such that its dependence on the structural parameter of our model, unlike most available results, motivates for further investigation. The simultaneous effects of varying yield stress and parameter ? on axial velocity, flow resistance and flow rate have been studied such that the differences between the Herschel?Bulkley fluid model and our current model can be pointed out. To validate the suitability of our model and some results in history, we have also obtained limiting results for particular values of ?.

Development of Pulse Ultrasonic Doppler Method for Flow Rate Measurements of Power Plant: Characteristics of Sound Pressure Distributions and Evaluation of the Hybrid Ultrasonic Flowmetering System Using TOF and UDM

2006 ◽  
Author(s):  
Hiroshige Kikura ◽  
Yuto Inoue ◽  
Masanori Aritomi ◽  
Michitsugu Mori
Keyword(s):  
Velocity Profile ◽  
Ultrasonic Velocity ◽  
Flow Rate ◽  
Time Of Flight ◽  
Velocity Profiles ◽  
Instantaneous Velocity ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Doppler Method ◽  
Flow Metering

A multi-beam pulse ultrasonic Doppler method has been developed for a new type of flow metering system. This new system is a hybrid of the time-of-flight type ultrasonic flowmeter and the ultrasonic velocity profile type flowmeter, having the advantages of these two types. Our final purpose is to apply the hybrid ultrasonic flow metering system to an accurate flow rate measurement of feed- or recirculation- water in nuclear power plants. The pulse ultrasonic Doppler method (UDM) has the capability to obtain instantaneous velocity profiles along an ultrasonic beam. The principle of the UDM flowmeter, which is one of the ultrasonic velocity profile type flowmeters, is based on the integration of an instantaneous velocity profile over a pipe diameter. The multi-beam system is expected to eliminate installation problems such as those of entry length, and also to follow transient flow rate more precisely by increasing the number of ultrasonic transducers. However, it needs reflectors for receiving ultrasonic Doppler signals. On the other hand, the time-of-flight (TOF) ultrasonic flow metering system does not need any reflector, but it needs profile factors (PFs) which depend on velocity profiles. PF is one of the important experimental coefficients for the accurate flow rate measurement. Therefore PFs must be corrected according to the changes in flow conditions. In the present study, we investigated to what degree the hybrid ultrasonic flow metering system can adjust the profile factors of the time-of-flight ultrasonic flow meters by using the multi-beam pulse ultrasonic Doppler method in metallic wall piping.

Experimental Investigation of Turbulent Boundary Layers Under Favorable Pressure Gradient

2010 ◽  
Author(s):  
Pranav Joshi ◽  
Joseph Katz
Keyword(s):  
Boundary Layer ◽  
Friction Coefficient ◽  
Pressure Gradient ◽  
Skin Friction ◽  
Velocity Profiles ◽  
Skin Friction Coefficient ◽  
Mean Velocity ◽  
Freestream Velocity ◽  
Favorable Pressure Gradient ◽  
The Mean

The goal of this research is to study the effect of favorable pressure gradient (FPG) on the near wall structures of a turbulent boundary layer on a smooth wall. 2D-PIV measurements have been performed in a sink flow, initially at a coarse resolution, to characterize the development of the mean flow and (under resolved) Reynolds stresses. Lack of self-similarity of mean velocity profiles shows that the boundary layer does not attain the sink flow equilibrium. In the initial phase of acceleration, the acceleration parameter, K = v/U2dU/dx, increases from zero to 0.575×10−6, skin friction coefficient decreases and mean velocity profiles show a log region, but lack universality. Further downstream, K remains constant, skin friction coefficient increases and the mean velocity profiles show a second log region away from the wall. In the initial part of the FPG region, all the Reynolds stress components decrease over the entire boundary layer. In the latter phase, they continue to decrease in the middle of the boundary layer, and increase significantly close to the wall (below y∼0.15δ), where they collapse when normalized with the local freestream velocity. Turbulence production and wallnormal transport, scaled with outer units, show self-similar profiles close to the wall in the constant K region. Spanwise-streamwise plane data shows evidence of low speed streaks in the log layer, with widths scaling with the boundary layer thickness.

scholarly journals Study of Slip Effects in Reverse Roll Coating Process Using Non-Isothermal Couple Stress Fluid

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1249
Author(s):  
Hasan Shahzad ◽  
Xinhua Wang ◽  
Muhammad Bilal Hafeez ◽  
Zahir Shah ◽  
Ahmed Mohammed Alshehri
Keyword(s):  
Pressure Gradient ◽  
Flow Rate ◽  
Couple Stress ◽  
Velocity Ratio ◽  
Closed Form Solution ◽  
Couple Stress Fluid ◽  
Slip Parameter ◽  
Roll Coating ◽  
Stress Parameter ◽  
The Impact

The non-isothermal couple stress fluid inside a reverse roll coating geometry is considered. The slip condition is considered at the surfaces of the rolls. To develop the flow equations, the mathematical modelling is performed using conservation of momentum, mass, and energy. The LAT (lubrication approximation theory) is employed to simplify the equations. The closed form solution for velocity, temperature, and pressure gradient is obtained. While the pressure and flow rate are obtained numerically. The impact of involved parameters on important physical quantities such as temperature, pressure, and pressure gradient are elaborated through graphs and in tabular form. The pressure and pressure gradient decreases for variation of the couple stress parameter and velocity ratio parameter K. While the variation of the slip parameter increases the pressure and pressure gradient inside the flow geometry. Additionally, flow rate decreases for the variation of the slip parameter as fluid starts moving rapidly along the roller surface. The most important physical quantity which is responsible for maintaining the quality of the coating and thickness is flow rate. For variation of both the couple stress parameter and the slip parameter, the flow rate decreases compared to the Newtonian case, consequently the coating thickness decreases for the variation of the discussed parameter.

Effects of heat transfer and the endoscope on Jeffrey fluid peristaltic flow in tubes

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
A.M. Abd-Alla ◽  
S.M. Abo-Dahab ◽  
M.A. Abdelhafez ◽  
Esraa N. Thabet
Keyword(s):  
Heat Transfer ◽  
Pressure Gradient ◽  
Flow Rate ◽  
Analytical Solutions ◽  
Volume Flow Rate ◽  
Peristaltic Flow ◽  
Volume Flow ◽  
Jeffrey Fluid ◽  
Temperature Profiles ◽  
Content Type

PurposeThis article aims to describe the effect of an endoscope and heat transfer on the peristaltic flow of a Jeffrey fluid through the gap between concentric uniform tubes.Design/methodology/approachThe mathematical model of the present problem is carried out under long wavelength and low Reynolds number approximations. Analytical solutions for the velocity, temperature profiles, pressure gradient and volume flow rate are obtained.FindingsThe results indicate that the effect of the wave amplitude, radius ratio, Grashof number, the ratio of relaxation to retardation times and the radius are very pronounced in the phenomena. Also, a comparison of obtaining an analytical solution against previous literatures shows satisfactory agreement.Originality/valueAnalytical solutions for the velocity, temperature profiles, pressure gradient and volume flow rate are obtained. Numerical integration is performed to analyze the pressure rise and frictional forces on the inner and outer tubes.

Numerical Optimization of the Inlet Velocity Profile Ingested by the Conical Draft Tube of a Hydraulic Turbine

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Sergio Galván ◽  
Marcelo Reggio ◽  
Francois Guibault
Keyword(s):  
Velocity Profile ◽  
Flow Rate ◽  
Numerical Optimization ◽  
Draft Tube ◽  
Velocity Profiles ◽  
Plant Performance ◽  
Swirl Number ◽  
Inlet Velocity ◽  
Turbine Performance ◽  
Low Head

Past numerical and experimental research has shown that the draft tube inlet velocity is critically important to hydropower plant performance, especially in the case of low-head installations. However, less is known about the influence of flow parameters on turbine performance particularly swirl distribution. Based on the influence of draft tube flow characteristics on the overall performance of a low-head turbine, this research proposes a methodology for optimizing draft tube inlet velocity profiles as a new approach to controlling the flow conditions in order to yield better draft tube and turbine performance. Numerical optimization methods have been used successfully for a variety of design problems. However, addressing the optimization of boundary conditions in hydraulic turbines poses a new challenge. In this paper, three different vortex equations for representing the inlet velocity profile are applied to a cone diffuser, and the behavior of the objective function is analyzed. As well, the influence of the quantitative correlation between the swirling flow at the cone inlet and the analytical blade shape, flow rate, and swirl number using the best inlet velocity profiles is evaluated. We also include a discussion on the development of a flow structure caused by the inlet swirl parameters. Finally, we present an analysis of the influence of flow rate and swirl number on the behavior of the optimization process.

scholarly journals Analytical Solutions for Flow of a Dusty Fluid Between Two Porous Flat Plates

1994 ◽  
Vol 116 (2) ◽  
pp. 354-356 ◽  
Author(s):  
Ali J. Chamkha
Keyword(s):  
Exact Solutions ◽  
Closed Form ◽  
Skin Friction ◽  
Analytical Solutions ◽  
Velocity Profiles ◽  
Flat Plates ◽  
Friction Coefficients ◽  
Dusty Fluid ◽  
Closed Form Solutions

Equations governing flow of a dusty fluid between two porous flat plates with suction and injection are developed and closed-form solutions for the velocity profiles, displacement thicknesses, and skin friction coefficients for both phases are obtained. Graphical results of the exact solutions are presented and discussed.

Large Eddy Simulation of Forced and Unforced Plane Jets Impinging on a Convex Surface

2014 ◽  
Author(s):  
N. Kharoua ◽  
L. Khezzar ◽  
Z. Nemouchi ◽  
M. AlShehhi
Keyword(s):  
Large Eddy Simulation ◽  
Velocity Profile ◽  
Axial Velocity ◽  
Velocity Profiles ◽  
Impinging Jets ◽  
Inlet Velocity ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Target Wall ◽  
The Mean

Large Eddy Simulation study of plane impinging jets with different inlet velocity profiles was conducted. The inlet velocity profile was forced at a frequency equal to 600Hz and amplitude equal to 30% of the mean inlet velocity. The Reynold number, based on the jet width W and the inlet velocity, is equal to 5600. The distance of the jet exit from the target wall was varied from 2W to 10W to cover different types of impinging jets with different flow structures. The time-averaged Nusselt Number Nu profiles, along the curved wall, are characterized by two peaks for the shortest distance 2W and only one peak, at the impingement region, for the largest distance 10W. The first peak, at the impingement region is investigated through profiles of the mean axial velocity, the rms axial velocity, the mean static pressure, and the mean static temperature plotted on the jet centerline. For the second peak of the Nu (2W case), the turbulence level and the thickness of the highly turbulent layer near the curved wall were depicted on curved lines parallel and very close to the target wall. Forcing the considered jets at 600Hz was found to reduce the Nu while a fully developed inlet velocity profile causes an important increase of the Nu at the impingement region compared with flat inlet velocity profiles.

Physical characteristics of subsonic jets in a cross-stream

1974 ◽  
Vol 62 (1) ◽  
pp. 41-64 ◽  
Author(s):  
P. Chassaing ◽  
J. George ◽  
A. Claria ◽  
F. Sananes
Keyword(s):  
Velocity Profile ◽  
Axial Velocity ◽  
Flow Characteristics ◽  
Cross Flow ◽  
Turbulent Jets ◽  
Velocity Profiles ◽  
Local Flow ◽  
Axial Velocity Profile ◽  
Velocity Decay ◽  
The Law

This paper deals with local flow characteristics of subsonic turbulent jets in the presence of a cross-flow. For the various types of jet considered (a cylindrical jet and coaxial jets) the experimental results concern the axes and the velocity profiles in the plane of symmetry of the flow. In the case of the cylindrical jet, the shape of the universal axial velocity profile is defined, as are the law of velocity decay along the axis and the laws of variation of the thicknesses of the jet. Finally, the existence of a link between the axis equation and the law of axial velocity decay in the zone of similarity of the velocity profiles is established.

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