Isosceles Triangular Ducts Research Articles

Combined free and forced laminar convection in thermal entrance region of horizontal triangular ducts.

Theoretical and experimental studies were made of the heat transfer at the thermal entrance region in a horizontal triangular duct, to obtain the local and mean Nusselt number of combined free and forced laminar convection for high Prandtl number fluid under the boundary condition of uniform wall temperature. For a region without free convection effects a solution of Nusselt number based on Leveque''s method was shown for arbitrary triangular ducts. On the other hand, for a region with the free convection effects a numerical solution of Nusselt number using the finite difference method for the triangular coordinate system was proposed for isosceles triangular ducts with apex angles of 30, 60 and 90 degrees. Furthermore, the influence of the rotation angle around the horizontal axis on Nusselt number was examined and suggested to be relatively small. The experimental results obtained by the electrochemical method support fairly well the theoretical results.

Combined free and forced laminar convection in triangular ducts.

A numerical method using the finite difference techniques for a triangular coordinates system is presented for flow and heat transfer problems of fully developed combined free and forced laminar convection in arbitrary triangular ducts, where the boundary condition with the axially uniform wall heat flux and the peripherally uniform wall temperature is taken into consideration. The numerical examples are carried out for horizontal isosceles and inclined equilateral triangular ducts. For the horizontal isosceles triangular ducts, correlative relationships with respect to fRe/(fRe)0 vs. ReRaPr and Nu/Nu0 vs. ReRaPr at Pr=0.73 are obtained for various vertex angles, where subscript 0 signifies the value of pure forced convection. Additionally, the influence of those relationships by Pr is examined. For inclined equilateral ducts with upward flow, fRe and Nu are correlated with the two modified parameters, Ra* and Re*, implicitly including an inclination angle. Furthermore, the influence of rotation and inclination angles on fRe and Nu is shown for equilateral triangular ducts.

Pressure Distributions in Porous Ducts of Arbitrary Cross Section

A general analytical method has been developed to approximate the pressure distribution along a porous duct of an arbitrary cross section with uniform fluid extraction or addition through the wall. Application of this method is made to a variety of cross sections including circular tubes, parallel plate channels, elliptical ducts, rectangular ducts, annular ducts, and isosceles triangular ducts. Comparisons have been made with results from existing literature on cases of the circular porous tube and the parallel porous plate channel in which exact solutions are available. A numerical solution for the case of a parallel channel consisting of an impermeable wall on one side and a porous wall on the other side is also presented. One important filter duct design criterion has been found for each of the above cases. At a critical wall Reynolds number, defined by flow velocity normal to the wall and the equivalent diameter of the duct, the pressure gradient along the filter duct approaches zero. The zero pressure gradient in a filter duct ensures uniform filtration of solid particles.

Transitional Flow in Isosceles Triangular Ducts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTransitional Flow in Isosceles Triangular DuctsRichard C. Cope and Richard W. HanksCite this: Ind. Eng. Chem. Fundamen. 1972, 11, 1, 106–117Publication Date (Print):February 1, 1972Publication History Published online1 May 2002Published inissue 1 February 1972https://doi.org/10.1021/i160041a016RIGHTS & PERMISSIONSArticle Views301Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (5 MB) Get e-Alerts

Birefringent flow visualization of transitional flow phenomena in an isosceles triangular duct

AbstractA flow visualization study was made with an optically birefringent solution of milling yellow dye in water flowing through a transparent duct of isoceles triangular cross section. The present data confirm a number of theoretical predictions concerning transitional phenomena in triangular ducts. One of the most interesting of these phenomena is the existence of a region of simultaneous laminar and turbulent flow in the duct. The present results, which agree with the theory, indicate an order of laminar and turbulent flow which is inverse to previous observations made with smoke filament tracings.

Geometric parameters for some flow channels

AbstractA method was proposed earlier(1) for prediction of the average velocity or pressure drop in the flow of non‐ Newtonian fluids in conduits of arbitrary cross section. The method requires only a knowledge of two geometric parameters which characterize the flow geometry, and the fluid model equation. In this paper, evaluations of geometric parameters are presented for infinite and finite (enclosed)square and triangular arrays of cylinders, and for regular polygonal and star‐shaped conduits. With these parameters, predictions of the average velocity or related variables for the Zlow of any arbitrary non‐Newtonian fluid can now be made. Comparisons are made with recent analytical solutions and experimental data pertaining to non‐Newtonian flow in concentric annuli, and equilateral and right isosceles triangular ducts, which give additional support to the reliability of the proposed method.

Laminar Heat Transfer and Pressure Drop in Isosceles Triangular, Right Triangular, and Circular Sector Ducts

Laminar Heat Transfer and Pressure Drop in Isosceles Triangular, Right Triangular, and Circular Sector Ducts

Pressure Drop Due to the Entrance Region in Ducts of Arbitrary Cross Section

A general analytical method has been devised for determining the pressure drop due to flow development in the entrance region of ducts of arbitrary cross section. The essential feature of the analysis is that the pressure drop can be determined without actually solving for the entrance-region velocity development. Instead, the calculation only requires a knowledge of the fully developed velocity profile. Application of the method is made to a variety of cross sections including the circular tube, elliptical ducts, rectangular ducts, isosceles triangular ducts, and annular ducts. Numerical results are presented and comparisons are made with available experiments and with prior analysis.

Laminar flow in isosceles triangular ducts

Laminar flow in isosceles triangular ducts