Approximate Calculation of Pressure Drop in Laminar Flow of Generalized Newtonian Liquid Through Channel of Noncircular Cross Section

1994 ◽  
Vol 59 (3) ◽  
pp. 603-615 ◽  
Author(s):  
Václav Dolejš ◽  
Ivan Machač ◽  
Petr Doleček
Keyword(s):  
Pressure Drop ◽  
Laminar Flow ◽  
Numerical Solution ◽  
Cross Section ◽  
Approximate Calculation ◽  
Newtonian Liquid ◽  
Straight Channel ◽  
Suggested Procedure ◽  
Noncircular Cross Section ◽  
Calculation Results

The paper presents a modification of the equations of Rabinowitsch-Mooney type for an approximate calculation of pressure drop in laminar flow of generalized Newtonian liquid through a straight channel whose cross section forms a simple continuous area. The suitability of the suggested procedure of calculation of pressure drop is demonstrated by the comparison of calculation results with both the published and original results of numerical solution and experiments.

Approximate Calculation of Pressure Drop in Laminar Flow of Generalized Newtonian Fluid Through Channels with Insert

1995 ◽  
Vol 60 (9) ◽  
pp. 1476-1491
Author(s):  
Václav Dolejš ◽  
Petr Doleček ◽  
Ivan Machač ◽  
Bedřich Šiška
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Laminar Flow ◽  
Numerical Solution ◽  
Newtonian Fluid ◽  
Calculation Method ◽  
Approximate Calculation ◽  
Creeping Flow ◽  
Experimental Results ◽  
Generalized Newtonian Fluid

An equation of Rabinowitsch-Mooney type has been suggested for approximate calculation of pressure drop in flow of generalized Newtonian fluid through channels with insert both in the region of creeping flow and at higher values of the Reynolds number, and this calculation method has been verified for four types of insert using own numerical solution and experimental results as well as literature data.

scholarly journals Flows of Dehaven Fluid in Symmetrically Curved Capillary Fissures and Tubes

2018 ◽  
Vol 23 (2) ◽  
pp. 521-550
Author(s):  
A. Walicka ◽  
J. Falicki ◽  
P. Jurczak
Keyword(s):  
Pressure Drop ◽  
Laminar Flow ◽  
Cross Section ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Velocity Flow ◽  
Hyperbolic Cosine ◽  
Analytical Expressions

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.

Large Scale Topology Optimization of 3D Static Mixers

2020 ◽  
Author(s):  
Sicheng Sun ◽  
Jaal Ghandhi ◽  
Xiaoping Qian
Keyword(s):  
Topology Optimization ◽  
Pressure Drop ◽  
Cross Section ◽  
Large Scale ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Straight Channel ◽  
Navier Stokes Equation ◽  
Static Mixers ◽  
Static Fluid

Abstract Topology optimization (TO) was conducted for three dimensional static fluid mixers. The problem is optimized using the weakly coupled Navier-Stokes equation at low Reynolds number (Re ≤ 1) and a convection-diffusion equation. The domain was discretized with up to 10 million cells. The optimizations were run with 1024 to 2048 CPUs on a national supercomputer. For a mixer in a square cross-section channel, the mixing was improved by 83% for a modest 2.5 times higher pressure drop compared with the open straight channel. For a cylindrical cross-section tee arrangement, the mixing improved by 91% with a 2.5 times higher pressure drop compared to the straight channel.

An Analysis of Laminar Flow and Pressure Drop in Complex Shaped Ducts

1976 ◽  
Vol 98 (4) ◽  
pp. 702-706 ◽  
Author(s):  
John P. Zarling
Keyword(s):  
Pressure Drop ◽  
Laminar Flow ◽  
Cross Section ◽  
Flow Rate ◽  
Series Solution ◽  
Complex Geometry ◽  
Constant Cross Section ◽  
Point Matching ◽  
Friction Factors ◽  
Flow Through

An analytical method is presented for solving the governing equation for fully developed, steady, incompressible laminar flow through ducts of constant cross-section having a complex geometry. The technique uses the Schwarz-Neumann alternating method along with least squares point matching. The method is applied to a complex shaped duct and the resulting velocity series solution is used to calculate the flow rate and pressure drop (f•Re) for a range of duct sizes. Numerical results are presented and compared with experimentally determined friction factors for a duct of similar geometry.

Hydrodynamics of a Body Moving Over a Mud Layer-Part II: Added-Mass and Damping Coefficients

1996 ◽  
Vol 40 (01) ◽  
pp. 39-45
Author(s):  
G. Zilman ◽  
L. Kagan ◽  
T. Miloh
Keyword(s):  
Integral Equation ◽  
Green Function ◽  
Numerical Solution ◽  
Cross Section ◽  
Water Layer ◽  
Added Mass ◽  
Boundary Integral ◽  
Newtonian Liquid ◽  
Periodic Oscillations ◽  
Damping Coefficients

A ship cross section undergoes periodic oscillations in a finite water layer, overlaying a mud layer. The upper fluid is considered to be inviscid, and the mud is modeled as a Newtonian liquid. The section contour is replaced by a distribution of wave sources with unknown strength, satisfying a corresponding boundary integral equation. Its kernel is expressed through a newly derived Green function. The numerical solution of the integral equation allows evaluation of the added-mass and damping coefficients. Specific computations pertaining to Lewis forms show a drastic dependence of the added-mass and damping coefficients on the mud thickness and density.

Backscattering Analysis of Cylinder Shaped Scatterer in Vegetation Medium: Comparison Between Theories

2020 ◽  
Vol 2 (1) ◽  
pp. 15-18
Author(s):  
Syabeela Syahali ◽  
Ewe Hong Tat ◽  
Gobi Vetharatnam ◽  
Li-Jun Jiang ◽  
Hamsalekha A Kumaresan
Keyword(s):  
Numerical Solution ◽  
Cross Section ◽  
Traditional Method ◽  
Microwave Remote Sensing ◽  
Solution Model ◽  
Complex Nature ◽  
Good Match ◽  
Equivalent Source ◽  
Backscattering Cross Section ◽  
Method Model

This paper analyses the backscattering cross section of a cylinder both using traditional method model and a new numerical solution model, namely Relaxed Hierarchical Equivalent Source Algorithm (RHESA). The purpose of this study is to investigate the prospect of incorporating numerical solution model into volume scattering calculation, to be applied into microwave remote sensing in vegetation area. Results show a good match, suggesting that RHESA may be suitable to be used to model the more complex nature of vegetation medium.

ESTIMATION OF PRESSURE DROP FOR NON-NEWTONIAN LIQUID FLOW THROUGH BENDS USING ADAPTIVE NON-PARAMETRIC MODEL

2020 ◽  
Vol 47 (1) ◽  
pp. 59-69
Author(s):  
Suman Debnath ◽  
Anirban Banik ◽  
Tarun Kanti Bandyopadhyay ◽  
Mrinmoy Majumder ◽  
Apu Kumar Saha
Keyword(s):  
Pressure Drop ◽  
Liquid Flow ◽  
Parametric Model ◽  
Newtonian Liquid ◽  
Flow Through ◽  
Non Parametric

Thermohydraulics of Laminar Flow Through Rectangular and Square Ducts With Transverse Ribs and Twisted Tapes

2006 ◽  
Vol 128 (10) ◽  
pp. 1070-1080 ◽  
Author(s):  
Debashis Pramanik ◽  
Sujoy K. Saha
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Laminar Flow ◽  
Laminar Flows ◽  
Short Length ◽  
Full Length ◽  
Twisted Tape ◽  
Twisted Tapes ◽  
Square Ducts ◽  
Better Than

The heat transfer and the pressure drop characteristics of laminar flow of viscous oil through rectangular and square ducts with internal transverse rib turbulators on two opposite surfaces of the ducts and fitted with twisted tapes have been studied experimentally. The tapes have been full length, short length, and regularly spaced types. The transverse ribs in combination with full-length twisted tapes have been found to perform better than either ribs or twisted tapes acting alone. The heat transfer and the pressure drop measurements have been taken in separate test sections. Heat transfer tests were carried out in electrically heated stainless steel ducts incorporating uniform wall heat flux boundary conditions. Pressure drop tests were carried out in acrylic ducts. The flow was periodically fully developed in the regularly spaced twisted-tape elements case and decaying swirl flow in the short-length twisted tapes case. The flow characteristics are governed by twist ratio, space ratio, and length of twisted tape, Reynolds number, Prandtl number, rod-to-tube diameter ratio, duct aspect ratio, rib height, and rib spacing. Correlations developed for friction factor and Nusselt number have predicted the experimental data satisfactorily. The performance of the geometry under investigation has been evaluated. It has been found that on the basis of both constant pumping power and constant heat duty, the regularly spaced twisted-tape elements in specific cases perform marginally better than their full-length counterparts. However, the short-length twisted-tape performance is worse than the full-length twisted tapes. Therefore, full-length twisted tapes and regularly spaced twisted-tape elements in combination with transverse ribs are recommended for laminar flows. However, the short-length twisted tapes are not recommended.

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