Cavitation control using passive flow control techniques
Article dans une revue avec comité de lecture
Passive flow control techniques, and particularly vortex generators have been used successfully in a broad range of aero- and hydrodynamics applications to alter the characteristics of boundary layer separation. This study aims to review how such techniques can mitigate the extent and impact of cavitation in incompressible flows. This review focuses first on vortex generators to characterize key physical principles. It then considers the complete range of passive flow control technologies, including surface conditioning and roughness, geometry modification, grooves, discharge, injection, obstacles, vortex generators, and bubble generators. The passive flow control techniques reviewed typically delay and suppress boundary layer separation by decreasing the pressure gradient at the separation point. The literature also identifies streamwise vortices that result in the transfer of momentum from the free stream to near-wall low energy flow regions. The area of interest concerns hydraulic machinery, whose performance and life span are particularly susceptible to cavitation. The impact on performance includes a reduction in efficiency and fluctuations in discharge pressure and flow, while cavitation can greatly increase wear of bearings, wearing rings, seals, and impeller surfaces due to excessive vibration and surface erosion. In that context, few studies have also shown the positive effects that passive controls can have on the hydraulic performance of centrifugal pumps, such as total head and efficiency. It is conceivable that a new generation of design in hydraulic systems may be possible if simple design features can be conceived to maximize power transfer and minimize losses and cavitation. There are still, however, significant research gaps in understanding a range of impact factors such as manufacturing processes, lifetime, and durability, and essentially how a static design can be optimized to deliver improved performance over a realistic range of operating conditions.
Fichier(s) constituant cette publication
Cette publication figure dans le(s) laboratoire(s) suivant(s)
Visualiser des documents liés par titre, auteur, créateur et sujet.
Article dans une revue avec comité de lectureA prototype device for measuring the volumetric flow-rate by counting vortices has been designed and realized. It consists of a square-section pipe in which are placed a two-dimensional bluff body and a strain gauge force ...
Article dans une revue avec comité de lectureTOMOV, Petar; KHELLADI, Sofiane; RAVELET, Florent; SARRAF, Christophe; BAKIR, Farid; VERTENOEUIL, P. (Elsevier, 2015)The injection of bubbles into an already cavitating flow is a way of influencing the typical cavitating behavior. The present article deals with experiments on aerated and non-aerated cavitation in a transparent horizontal ...
Numerical Investigation of Parietal Pressure Distribution on NACA0012 Wing Controlled by Micro-cylindrical Rod Arranged in Tandem Article dans une revue avec comité de lectureLARABI, Abderrahim; PEREIRA, Michael; RAVELET, Florent; AZZAM, Tarik; OUALLI, Hamid; MENFOUKH, Laiche; BAKIR, Farid (Inderscience Publishers, 2022)The aim of this study is to investigate the influence of disturbed freestream flow by a small cylinder on the laminar separated boundary layer over NACA0012 wing operating at a Reynolds number of Rec = 4.45 × 105. A detailed ...
Performance and flow characteristics of the optimum rotors of Betz, Joukowsky, and Glauert at low tip-speed ratio Article dans une revue avec comité de lectureThe advent of the Internet of Things technology has led to a renewed interest in the use of low tip-speed ratio micro-scale wind turbines to supply power to battery-less microsystems. At low tip-speed ratio ( λ), the blade ...
Experimental investigation of the effects of the Reynolds number on the performance and near wake of a wind turbine Article dans une revue avec comité de lectureWind tunnel experiments provide worthwhile insights for designing efficient micro wind energy harvesters and large-scale wind turbines. As wind tunnel tests with large-scale wind turbines are expensive and not always ...