Laminar Non-Newtonian Fluid Flow in Noncircular Ducts and Microchannels

2008 ◽  
Vol 130 (11) ◽  
Author(s):  
Y. S. Muzychka ◽  
J. Edge
Keyword(s):  
Fluid Flow ◽  
Newtonian Fluid ◽  
Circular Tube ◽  
Characteristic Length ◽  
Current Model ◽  
Rectangular Duct ◽  
Cross Sectional ◽  
Circular Annulus ◽  
Proposed Model ◽  
Power Law Fluids

Non-Newtonian fluid flow in noncircular ducts and microchannels is examined. A simple model is proposed for power law fluids based on the Rabinowitsch–Mooney formulation. By means of a new characteristic length scale, the square root of the cross-sectional area, it is shown that dimensionless wall shear stress can be made a weak function of duct shape. The proposed model is based on the solution for the rectangular duct and has an accuracy of ±10% or better. The current model eliminates the need for tabulated data or equations for several common shapes found in handbooks, namely, circular tube, elliptic tube, parallel channel, rectangular duct, isosceles triangular duct, circular annulus, and polygonal ducts.

Laminar Forced Convection Heat Transfer in the Combined Entry Region of Non-Circular Ducts

2004 ◽  
Vol 126 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Y. S. Muzychka ◽  
M. M. Yovanovich
Keyword(s):  
Circular Tube ◽  
Convection Heat Transfer ◽  
Numerical Data ◽  
Asymptotic Results ◽  
Cross Sectional ◽  
Fully Developed Flow ◽  
Nusselt Numbers ◽  
Proposed Model ◽  
Laminar Forced Convection ◽  
Plate Channel

A new model for predicting Nusselt numbers in the combined entrance region of non-circular ducts and channels is developed. This model predicts both local and average Nusselt numbers and is valid for both isothermal and isoflux boundary conditions. The model is developed using the asymptotic results for convection from a flat plate, thermally developing flows in non-circular ducts, and fully developed flow in non-circular ducts. Through the use of a novel characteristic length scale, the square root of cross-sectional area, the effect of duct shape on Nusselt number is minimized. Comparisons are made with several existing models for the circular tube and parallel plate channel and with numerical data for several non-circular ducts. Agreement between the proposed model and numerical data is within ±15percent or better for most duct shapes.

Friction Factor of Silicon Dioxide-Water Colloidal Suspension Flow in Circular and Square Tubes

2016 ◽  
Author(s):  
Md. Tanveer Sharif ◽  
Sarbottam Pant ◽  
Clement C. Tang
Keyword(s):  
Fluid Flow ◽  
Turbulent Flow ◽  
Silicon Dioxide ◽  
Friction Factor ◽  
Newtonian Fluid ◽  
Colloidal Suspension ◽  
Suspension Flow ◽  
Cross Sectional ◽  
Friction Factors ◽  
Sectional Shape

The present study focuses on the friction factors of a colloidal suspension flow in circular and square tubes. The colloidal suspension was made of silicon dioxide nanoparticles dispersed in distilled water at a concentration of 9.58% by volume. The viscosity and shear stress of the suspension were measured and it was found that the fluid exhibited non-Newtonian behavior. The rheological behavior of the suspension could be adequately modeled as a power-law generalized Newtonian fluid (GNF). When the consistency and the flow behavior indices of the suspension were properly evaluated, the friction factors of the suspension flowing in tubes with circular and square cross-sections exhibited similarities with those of Newtonian fluid flow. In fully-developed laminar flow, the Poiseuille number for the suspension was similar to that for a Newtonian fluid flow. In turbulent flow, the Dodge and Metzner’s relations for the friction factor and a generalized Reynolds number can be used to adequately describe the suspension in turbulent flow. Observations from the friction factor measurements showed that the onsets of transition to turbulent flow vary with the cross-sectional shape of the tube and differ from those of Newtonian fluid flow. This might suggest that the cross-sectional shape of the flow passage and the presence of nanoparticles could affect the onset of transition to turbulent flow for the suspension.

NUMERICAL MODELING OF NON-NEWTONIAN FLUID FLOW BETWEEN POROUS DISKS IN THE PRESENCE OF NANOPARTICLES

2017 ◽  
Vol 8 (1) ◽  
pp. 67-83
Author(s):  
M. Zubair Akbar Qureshi ◽  
Kashif Ali ◽  
Muhammad Farooq Iqbal ◽  
Muhammad Ashraf
Keyword(s):  
Numerical Modeling ◽  
Fluid Flow ◽  
Newtonian Fluid

NUMERICAL ANALYSIS OF NEWTONIAN FLUID FLOW VARYING THE CONTRACTION GEOMETRY USING OPENFOAM

2019 ◽  
Author(s):  
João Pedro Costa Eliziário ◽  
andrevidy honório ◽  
Marcos Lourenço ◽  
Elie Luis Martínez Padilla
Keyword(s):  
Fluid Flow ◽  
Numerical Analysis ◽  
Newtonian Fluid

A Non-Newtonian Fluid Flow Model for the Slip Condition on Blood Flow through a Stenosed Artery using Power-law Fluid

2018 ◽  
Vol 9 (7) ◽  
pp. 871-879
Author(s):  
Rajesh Shrivastava ◽  
R. S. Chandel ◽  
Ajay Kumar ◽  
Keerty Shrivastava and Sanjeet Kumar
Keyword(s):  
Blood Flow ◽  
Fluid Flow ◽  
Newtonian Fluid ◽  
Power Law ◽  
Flow Model ◽  
Slip Condition ◽  
Power Law Fluid ◽  
Stenosed Artery ◽  
Flow Through

scholarly journals Determinants of revenue management practices and their impacts on the financial performance of hotels in Kenya: a proposed theoretical framework

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Michael Murimi ◽  
Billy Wadongo ◽  
Tom Olielo
Keyword(s):  
Financial Performance ◽  
Revenue Management ◽  
Management Practices ◽  
Theoretical Framework ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Second Stage ◽  
Theoretical Structure ◽  
Proposed Model ◽  
Conceptual Paper

AbstractThis conceptual paper aims at identifying a theoretical framework for the determinants of revenue management (RM) practices and their impacts on the financial performance of hotels. To create this framework, a two-phased process is employed where the first stage involves an explicit examination of the literature related to practices of revenue management and their determinants and to hotel financial performance. The second stage involves an enhancement of the framework. The theoretical structure is developed based on past theoretical explanations, and empirical analysis is conducted in the fields of revenue management. The researchers propose a theoretical framework illustrating how revenue management practices and their determinants affect the financial performance of Kenyan hotels. The use of contingency theory and its justifications and inadequacies among studies on revenue management in hotels is highlighted. The methods highlighted by the reviewed theoretical framework may be utilized to organize revenue management (RM) practices and their determinants for Kenyan hotels. Measurements for the financial performance of hotels are also described. Last, the researchers call for empirical research that authenticates the proposed model using a cross-sectional survey. The present work can inspire scholars and specialists to determine how RM practices and their determinants impact the financial performance of hotels. By assimilating knowledge from numerous disciplines, this paper emphasizes aggregated awareness surrounding the conceptualization of RM, RM practices adopted in hotels, and the financial performance of hotels.

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