scholarly journals Flows of Newtonian and Power-Law Fluids in Symmetrically Corrugated Cappilary Fissures and Tubes

2018 ◽  
Vol 23 (1) ◽  
pp. 187-211 ◽  
Author(s):  
A. Walicka

AbstractIn this paper, an analytical method for deriving the relationships between the pressure drop and the volumetric flow rate in laminar flow regimes of Newtonian and power-law fluids through symmetrically corrugated capillary fissures and tubes is presented. This method, which is general with regard to fluid and capillary shape, can also be used as a foundation for different fluids, fissures and tubes. It can also be a good base for numerical integration when analytical expressions are hard to obtain due to mathematical complexities. Five converging-diverging or diverging-converging geometrics, viz. wedge and cone, parabolic, hyperbolic, hyperbolic cosine and cosine curve, are used as examples to illustrate the application of this method. For the wedge and cone geometry the present results for the power-law fluid were compared with the results obtained by another method; this comparison indicates a good compatibility between both the results.

2018 ◽  
Vol 23 (2) ◽  
pp. 521-550
Author(s):  
A. Walicka ◽  
J. Falicki ◽  
P. Jurczak

Abstract In this paper, an analytical method for deriving the relationships between the pressure drop and the volumetric flow rate in laminar flow regimes of DeHaven type fluids through symmetrically corrugated capillary fissures and tubes is presented. This method, which is general with regard to fluid and capillary shape, can also be used as a foundation for different fluids, fissures and tubes. It can also be a good base for numerical integration when analytical expressions are hard to obtain due to mathematical complexities. Five converging-diverging or diverging-converging geometrics, viz. variable cross-section, parabolic, hyperbolic, hyperbolic cosine and cosine curve, are used as examples to illustrate the application of this method. Each example is concluded with a presentation of the formulae for the velocity flow on the outer surface of a thin porous layer. Upon introduction of hindrance factors, these formulae may be presented in the most general forms.


2012 ◽  
Vol 170-173 ◽  
pp. 2601-2608
Author(s):  
Xue Li Xia ◽  
Hong Fu Qiang ◽  
Wang Guang

To evaluate the effect of a converging injector geometry, volumetric flow rate and gallant content on the pressure drop, the velocity and viscosity fields, the governing equations of the steady, incompressible, isothermal, laminar flow of a Power-Law, shear-thinning gel propellant in a converging injector were formulated, discretized and solved. A SIMPLEC numerical algorithm was applied for the solution of the flow field. The results indicate that the mean apparent viscosity decreases with increasing the volumetric flow rate and increasing the gallant content results in an increase in the viscosity. The results indicate also that the convergence angle can produce additional decrease in the mean apparent viscosity of the fluid. The mean apparent viscosity decreases significantly with increasing the convergence angle of the injector, and its value is limited by the Newtonian viscosity η∞. The effect of the convergence angle on the mean apparent viscosity is more significant than the effect of the volumetric flow rate and the gallant content on the mean apparent viscosity. Additional decreasing the viscosity results in increasing the pressure drop with increasing convergence angle. It is important to injector design that the viscosity decreasing and the pressure drop increasing are took into account together.


1982 ◽  
Vol 104 (3) ◽  
pp. 182-186 ◽  
Author(s):  
J. B. Shukla ◽  
S. P. Gupta

Effects of the consistency variation on the peristaltic transport of a non-Newtonian power-law fluid fluid through a tube have been investigated by taking into account the existence of a peripheral layer. It is shown that the flow rate flux, for zero pressure drop, increases as the amplitude of the peristaltic wave increases but it decreases due to the pseudoplastic nature of the fluid. It is also noted that, for zero pressure drop, the flux does not depend on the consistency of peripheral layer while the friction decreases as this consistency decreases. However, for nonzero pressure drop, the flux increases and the friction force decreases as the consistency of peripheral layer fluid decreases.


2012 ◽  
Vol 198-199 ◽  
pp. 128-132
Author(s):  
Yong Ding ◽  
Fu Xin Yang ◽  
Jian Qiang Bao

The distribution of the speed and shear stress in power-law fluid with the laminar flow in the pipe were analyzed in this paper, then, the flow rate was calculated. Moreover, the stop pipe diameter was designed by calculating the balance of shear stress of power-law fluid in the pipe and the gravity of filling fluid. The conclusion: Ideal stop pipe diameter of power-law fluid is related to fluid properties, pressure and the acceleration of gravity.


1989 ◽  
Vol 199 ◽  
pp. 563-568 ◽  
Author(s):  
S. M. Richardson

It is well-known that laminar flow of a liquid in a duct is predicted to choke if the viscosity of the liquid increases exponentially with increasing pressure. In other words, the pressure drop in the duct is predicted to become unbounded when the volumetric flow rate reaches a critical finite value. Choking is not observed in practice, however: the reason why is investigated here. It is shown that choking is always predicted to occur if the viscosity is independent of temperature or heat generation by viscous dissipation is neglected. If the viscosity decreases exponentially with increasing temperature and heat generation is not neglected, however, and if the temperature field is fully developed or if the flow is adiabatic, it is shown that choking is predicted not to occur.


1996 ◽  
Vol 118 (1) ◽  
pp. 29-35 ◽  
Author(s):  
K. Minemura ◽  
K. Egashira ◽  
K. Ihara ◽  
H. Furuta ◽  
K. Yamamoto

A turbine flowmeter is employed in this study in connection with offshore oil field development, in order to measure simultaneously both the volumetric flow rates of air-water two-phase mixture. Though a conventional turbine flowmeter is generally used to measure the single-phase volumetric flow rate by obtaining the rotational rotor speed, the method proposed additionally reads the pressure drop across the meter. After the pressure drop and rotor speed measured are correlated as functions of the volumetric flow ratio of the air to the whole fluid and the total volumetric flow rate, both the flow rates are iteratively evaluated with the functions on the premise that the liquid density is known. The evaluated flow rates are confirmed to have adequate accuracy, and thus the applicability of the method to oil fields.


Author(s):  
Cunlu Zhao ◽  
Chun Yang

Electroosmotic flow of power-law fluids in a slit channel is analyzed. The governing equations including the linearized Poisson–Boltzmann equation, the Cauchy momentum equation and the continuity equation are solved to seek analytical expressions for the shear stress, dynamic viscosity and velocity distributions. Specifically, exact solutions of the velocity distributions are explicitly found for several special values of the flow behavior index. Furthermore, with the implementation of an approximate scheme for the hyperbolic cosine function, approximate solutions of the velocity distributions are obtained. In addition, a mathematical expression for the average electroosmotic velocity is derived for large values of the dimensionless electrokinetic parameter, κH, in a fashion similar to the Smoluchowski equation. Hence, a generalized Smoluchowski velocity is introduced by taking into account contributions due to the finite thickness of the electric double layer and the flow behavior index of power-law fluids. Finally, calculations are performed to examine the effects of κH, flow behavior index, double layer thickness, and applied electric field on the shear stress, dynamic viscosity, velocity distribution, and average velocity/flow rate of the electroosmotic flow of power-law fluids.


2010 ◽  
Vol 165 (21-22) ◽  
pp. 1442-1461 ◽  
Author(s):  
Saroj K. Panda ◽  
R.P. Chhabra

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