On riblets in laminar flows

1989 ◽  
pp. 51-65 ◽  
Author(s):  
O. Pironneau ◽  
G. Arumugam
Keyword(s):  
Laminar Flows

VISUALIZATION OF HEAT TRANSFER IN UNSTEADY LAMINAR FLOWS

2011 ◽  
Vol 3 (1) ◽  
pp. 31-47 ◽  
Author(s):  
Michel F. M. Speetjens ◽  
Anton A. van Steenhoven
Keyword(s):  
Heat Transfer ◽  
Laminar Flows

VISCOSITY EFFECTS ON LIQUID-LIQUID DISPERSION IN LAMINAR FLOWS

2009 ◽  
Author(s):  
Charbel Habchi ◽  
Sofiane Ouarets ◽  
Thierry Lemenand ◽  
Dominique Della-Valle ◽  
Jerome Bellettre ◽  
...  
Keyword(s):  
Laminar Flows ◽  
Liquid Dispersion ◽  
Viscosity Effects

COMPUTATIONAL ANALYSIS OF LAMINAR FLOWS IN A POROUS MEDIUM COMPOSED OF CORN COBS

2019 ◽  
Author(s):  
Hélio Ribeiro Neto ◽  
Pedro Ricardo Corrêa Souza ◽  
Ítalo Augusto Magalhães de Ávila ◽  
Aristeu Silveira Neto
Keyword(s):  
Porous Medium ◽  
Computational Analysis ◽  
Laminar Flows ◽  
Corn Cobs

Modeling of pressure losses on friction in three-layer laminar flows

2003 ◽  
Vol 3 ◽  
pp. 208-219
Author(s):  
A.M. Ilyasov
Keyword(s):  
Pressure Loss ◽  
Gas Flow ◽  
Mutual Influence ◽  
Fluid Model ◽  
Immiscible Liquid ◽  
Laminar Flows ◽  
Pressure Losses ◽  
Flow Parameters ◽  
Interphase Boundaries ◽  
Closing Relations

In this paper we propose a model for determining the pressure loss due to friction in each phase in a three-layer laminar steady flow of immiscible liquid and gas flow in a flat channel. This model generalizes an analogous problem for a two-layer laminar flow, proposed earlier. The relations obtained in the final form for the pressure loss due to friction in liquids can be used as closing relations for the three-fluid model. These equations take into account the influence of interphase boundaries and are an alternative to the approach used in foreign literature. In this approach, the wall and interphase voltages are approximated by the formulas for a single-phase flow and do not take into account the mutual influence of liquids on the loss of pressure on friction in phases. The distribution of flow parameters in these two models is compared.

Theoretical analysis of annular laminar flows with MHD interaction driven by rotating co‐axial cylinder

2021 ◽  
Vol 104 (2) ◽  
pp. 12311
Author(s):  
Ryo Sasaki ◽  
Takayasu Fujino ◽  
Hidemasa Takana ◽  
Hiromichi Kobayashi
Keyword(s):  
Theoretical Analysis ◽  
Laminar Flows ◽  
Axial Cylinder

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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