Effects of axial rectangular groove on turbulent Taylor-Couette flow from analysis of experimental data
TypeArticles dans des revues avec comité de lecture
The relationship between a rough or structured surface topology and its hydraulic resistance was analysed in the case of fully turbulent Taylor-Couette flow at fixed radii ratio η = 0.9375 and for Reynolds numbers Re i from 2×10 4 to 13×10 4. Three configurations of inner cylinder having 6, 12 and 24 grooves of a same rectangular shape and regularly distributed were compared to a reference smooth cylinder with only inner cylinder rotating. Such configurations are common in electric motors of high power density where a better understanding of flow pattern and heat transfer is essential to enhance their design and to develop appropriate cooling system. Torque and pointwise velocity measurements were performed. The effects of the flow modulations induced by the grooves on the friction coefficient and the flow features were examined. The results showed significant difference in the flow pattern and an increase of the friction coefficient with increasing the groove number. However, the drag-increasing capacity of each groove was further reduced by increasing the groove number. It was also found that, the local scaling exponent between friction coefficient and Reynolds number was insensitive to the present surface roughness, suggesting that the bulk flow contribution is similar for all the four configurations.
Showing items related by title, author, creator and subject.
RAVELET, Florent; BAKIR, Farid; KHELLADI, Sofiane; REY, Robert (Elsevier, 2013)This article presents an experimental study of the hydraulic transport of very large solid particles (above 5 mm) in an horizontal pipe. Two specific masses are used for the solids. The solids are spheres that are large ...
DANLOS, Amélie; MÉHAL, Jean-Elie; RAVELET, Florent; COUTIER-DELGOSHA, Olivier; BAKIR, Farid (ASME, 2014)Instabilities of a partial cavity developed on a hydrofoil, a converging-diverging step, or in an interblade channel have already been investigated in many previous works. The aim of this study is to evaluate a passive ...
NOURI, Hussain; DANLOS, Amélie; RAVELET, Florent; BAKIR, Farid; SARRAF, Christophe (2013)The purpose of this work is to study experimentally the aerodynamic characteristics of a subsonic counter-rotating axial-flow fans system operating in a ducted configuration. The fans of diameter D = 375 mm were designed ...
Experimental comparison between a counter-rotating axial-flow fan and a conventional rotor-stator stage WANG, Juan; RAVELET, Florent; BAKIR, Farid (2013)Based on the requirement of energy consumption level and weight and dimension restriction, compact axial machines are highly demanded in many industrial fields. The counter-rotating axial-flow fans could be a promising way ...
Experimental and Numerical Analysis of the Flow Inside a Configuration Including an Axial Pump and a Tubular Exchanger SOLIS, Moises; RAVELET, Florent; KHELLADI, Sofiane; BAKIR, Farid (ASME, 2010)In centrifugal and axial pumps, the flow is characterized by a turbulent and complex behavior and also by physical mechanisms such as cavitation and pressure fluctuations that are mainly due to the strong interactions ...