One-Directional Thermogravitational Movement of Viscous Fluid in a Flat Channel with a Given Flow Rate

2018 ◽  
Keyword(s):  
Viscous Fluid ◽  
Flow Rate ◽  
Flat Channel

scholarly journals Influence of Magnetic Field on the Peristaltic Flow of a Viscous Fluid through a Finite-Length Cylindrical Tube

2010 ◽  
Vol 7 (3) ◽  
pp. 169-176 ◽  
Author(s):  
S. K. Pandey ◽  
Dharmendra Tripathi
Keyword(s):  
Magnetic Field ◽  
Viscous Fluid ◽  
Transverse Magnetic Field ◽  
Finite Length ◽  
Flow Rate ◽  
Hartmann Number ◽  
Volume Flow Rate ◽  
Critical Value ◽  
Transverse Magnetic ◽  
Volume Flow

The paper presents an analytical investigation of the peristaltic transport of a viscous fluid under the influence of a magnetic field through a tube of finite length in a dimensionless form. The expressions of pressure gradient, volume flow rate, average volume flow rate and local wall shear stress have been obtained. The effects of the transverse magnetic field and electrical conductivity (i.e. the Hartmann number) on the mechanical efficiency of a peristaltic pump have also been studied. The reflux phenomenon is also investigated. It is concluded, on the basis of the pressure distribution along the tubular length and pumping efficiency, that if the transverse magnetic field and the electric conductivity increase, the pumping machinery exerts more pressure for pushing the fluid forward. There is a linear relation between the averaged flow rate and the pressure applied across one wavelength that can restrain the flow due to peristalsis. It is found that there is a particular value of the averaged flow rate corresponding to a particular pressure that does not depend on the Hartmann number. Naming these values ‘critical values’, it is concluded that the pressure required for checking the flow increases with the Hartmann number above the critical value and decreases with it below the critical value. It is also inferred that magneto-hydrodynamic parameters make the fluid more prone to flow reversal. The conclusion applied to oesophageal swallowing reveals that normal water is easier to swallow than saline water. The latter is more prone to flow reversal. A significant difference between the propagation of the integral and non-integral number of waves along the tube is that pressure peaks are identical in the former and different in the latter cases.

Vortex Pump as Turbine for Energy Recovery in Viscous Fluid Flows with Reynolds Number Effect

2021 ◽  
Author(s):  
Wen-Guang LI
Keyword(s):  
Reynolds Number ◽  
Viscous Fluid ◽  
Flow Rate ◽  
Power Efficiency ◽  
Stokes Equations ◽  
Entropy Generation Rate ◽  
Hydraulic Loss ◽  
Centrifugal Pumps ◽  
Vortex Pump ◽  
Turbine Mode

Abstract A vortex pump with a specific speed of 76 was studied in its turbine mode by using Fluent 6.3 based on the steady, three-dimensional, incompressible, Reynolds time-averaged Navier-Stokes equations, standard k-? turbulence model and non-equilibrium wall function in multiple reference system. The performance and flow structure of six liquids with different densities and viscosities were characterized, and the hydraulic, volumetric, and mechanical losses were discomposed. The correction factors of flow rate, head, shaft-power, efficiency, and disc friction power in turbine mode were correlated with impeller Reynolds number at three operational points. The conversion factors of flow rate, head, efficiency from the pump mode to the turbine mode were expressed with Reynolds number and compared with the counterparts of centrifugal pumps in the literature. It was indicated that the vortex pump can produce power as a turbine but becomes inefficient with increasing viscosity or decreasing impeller Reynolds number, especially as the number is smaller than 104 due to increased hydraulic, volumetric, and mechanical power losses. A vortex structure with radial, axial, and meridian vortices occurs in the impeller at different flow rates and viscosities. The incidence at blade leading edge and deviation angle at blade trailing edge depend largely on flow rate and viscosity. The impeller should be modified to improve its hydraulic performance under highly viscous fluid flow conditions. The entropy generation rate method cannot demonstrate the change in hydraulic loss with viscosity when the Reynolds number is below 104.

ITER FW cooling by a flat channel, adapted to low flow rate and high pressure drop

2011 ◽  
Vol 86 (12) ◽  
pp. 2971-2982 ◽  
Author(s):  
I.B. Ovchinnikov ◽  
D.E. Bondarchuk ◽  
A.A. Gervash ◽  
D.A. Glazunov ◽  
A.O. Komarov ◽  
...  
Keyword(s):  
High Pressure ◽  
Pressure Drop ◽  
Flow Rate ◽  
Low Flow ◽  
Flat Channel ◽  
High Pressure Drop ◽  
Low Flow Rate

scholarly journals The Effects of Fluid Viscosity on the Orifice Rotameter

2016 ◽  
Vol 16 (2) ◽  
pp. 87-95 ◽  
Author(s):  
Wei Jiang ◽  
Tao Zhang ◽  
Ying Xu ◽  
Huaxiang Wang ◽  
Xiaoli Guo ◽  
...  
Keyword(s):  
Viscous Fluid ◽  
Flow Rate ◽  
Theoretical Models ◽  
Maximum Error ◽  
Measurement Model ◽  
High Viscosity ◽  
Fluid Viscosity ◽  
Fluid Medium ◽  
Viscous Shear Stress ◽  
Viscous Shear

Abstract Due to the viscous shear stress, there is an obvious error between the real flow rate and the rotameter indication for measuring viscous fluid medium. At 50 cSt the maximum error of DN40 orifice rotameter is up to 35 %. The fluid viscosity effects on the orifice rotameter are investigated using experimental and theoretical models. Wall jet and concentric annulus laminar theories were adapted to study the influence of viscosity. And a new formula is obtained for calculating the flow rate of viscous fluid. The experimental data were analyzed and compared with the calculated results. At high viscosity the maximum theoretical results error is 6.3 %, indicating that the proposed measurement model has very good applicability.

Fluid flow through the hydraulic resistance with a dynamically variable geometry

2017 ◽  
Vol 12 (1) ◽  
pp. 59-66 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh. Nasibullaeva
Keyword(s):  
Fluid Flow ◽  
Hydraulic Resistance ◽  
Flow Rate ◽  
Dynamic Change ◽  
Variable Geometry ◽  
Transverse Compression ◽  
Flat Channel ◽  
Channel Geometry ◽  
Flow Through ◽  
Through Hole

In this paper the fluid flow in a flat channel with a hydraulic resistance is studied for two cases of a dynamic change in the channel geometry: transverse compression of the opening of the hydraulic resistance (the flow is caused by a pressure drop applied to the layer) and longitudinal movement of the hydraulic resistance along the channel (the flow is caused by this movement). It is obtained that in a geometry with transverse compression the flow is laminar without the formation of vortices. In a geometry with longitudinal movement of the hydraulic resistance the flow rate of the liquid remains constant with the formation of stable vortices that move along the channel at the rate of motion of the hydraulic resistance. On the base of the modeling results an analytical model that takes into account the flow rate of the fluid from the width of the through hole of the resistance is constructed. This model contains four interpolation parameters and it can be used as an element of a computational stand for determining the generalized flow of liquid in the system under consideration.

Study on Critical Heat Flux of High Velocity Liquid Flow

2007 ◽  
Author(s):  
Hisashi Sakurai ◽  
Yasuo Koizumi ◽  
Hiroyasu Ohtake
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
Flow Rate ◽  
High Velocity ◽  
Film Flow ◽  
Flow Boiling ◽  
Flow Channel ◽  
Heat Transfer Surface ◽  
Flat Channel

Critical heat flux experiments of subcooled, thin, and high-velocity water flow were performed. The test flow channel was rectangular. The width of the flow channel was 2 mm and the height was 0.5 mm or 0.2 mm. The heat transfer surface was 2 mm × 2 mm. At the low heat flux, tinny bubbles were formed at the downstream part of the test heating surface. As the heat flux was increased, the bubble diameter increased and the coalescence of bubbles occurred. Then, the coalesced bubbles grew larger to cover the whole area of the heat transfer surface. Finally, the dried area appeared at the downstream end of the heat transfer surface to cause the critical heat flux condition. The critical heat flux was considerably higher than that of the subcooled flow boiling for the usual-size pipe as well as those of the saturated and the subcooled pool nucleate boiling. As the flow rate was increased, the period between the onset of boiling and the critical heat flux occurrence became narrow. The critical heat flux in the present experiments where the heat transfer surface was located at the just downstream of the flat channel outlet was considerably larger than those in the previous experiments where the heat transfer surface was located at the outlet end of the flat channel or the upstream of the outlet. By producing a fast jet along the surface and providing enough space for generated bubbles to leave from the surface, the critical heat flux was considerably augmented. Critical heat fluxes obtained in the present experiments were in in-between of the correlations for the flowing-upward film flow and for the flowing-downward film flow. The increasing trend for the flow rate was similar to that of the correlations.

scholarly journals MHD flow of an elastico-viscous fluid under periodic body acceleration

2000 ◽  
Vol 23 (11) ◽  
pp. 795-799 ◽  
Author(s):  
E. F. El-Shehawey ◽  
Elsayed M. E. Elbarbary ◽  
N. A. S. Afifi ◽  
Mostafa Elshahed
Keyword(s):  
Magnetic Field ◽  
Exact Solution ◽  
Viscous Fluid ◽  
Unsteady Flow ◽  
Flow Rate ◽  
Axial Velocity ◽  
Mhd Flow ◽  
Body Acceleration ◽  
Electrical Conducting ◽  
Analytical Expressions

Magnetohydrodynamic (MHD) flow of blood has been studied under the influence of body acceleration. With the help of Laplace and finite Hankel transforms, an exact solution is obtained for the unsteady flow of blood as an electrical conducting, incompressible and elastico-viscous fluid in the presence of a magnetic field acting along the radius of the pipe. Analytical expressions for axial velocity, fluid acceleration and flow rate has been obtained.

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