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.
NOURI, Hussain; RAVELET, Florent; BAKIR, Farid; SARRAF, Christophe; REY, Robert (ASME, 2012)An experimental study on the design of counter-rotating axial-flow fans was carried out. The fans were designed using an inverse method. In particular, the system is designed to have a pure axial discharge flow. The ...
Etude numérique des gains de performances et de capacité d'aspiration apportés par un étage axial contra-rotatif par rapport à une pompe mono-rotor. DANLOS, Amélie; RAVELET, Florent; SOLIS, Moises; BAKIR, Farid (2013)This study deals with the development of an efficient method of design for subsonic conter-rotating axial flow turbomachineries. From specifications of a reference axial pump with only one rotor, two configurations of ...
Etude expé́rimentale du transport hydraulique de grandes particules en conduite horizontale et en forme de S RAVELET, Florent; LEMAIRE, Antoine; BAKIR, Farid (2011)We study the pressure drop and flow regimes for large spheres with respect to the diameter of the pipe (5, 10 and 15%) by differential pressure measurements and visualizations. Two densities are used. The losses are smaller ...
Influence of design parameters on the global performances of low-speed counter-rotating axial-flow fans WANG, Juan; RAVELET, Florent; BAKIR, Farid (2014)The present work aims at experimentally investigating the effects of some parameters on the performances of a counter-rotating stage, and on the instationary flow between the rotors. Three counter-rotating fans, which have ...
Experimental study of blade thickness effects on the overall and local performances of a Controlled Vortex Designed axial-ﬂow fan SARRAF, Christophe; NOURI, Hussain; RAVELET, Florent; BAKIR, Farid (Elsevier, 2011)The purpose of this work is to study the effects of blade thickness on the performances of an axial-ﬂow fan. Two fans that differ only in the thickness of their blades were studied. The ﬁrst fan was designed to be part of ...