Caractérisations quantitative et qualitative des effluents de cave et possibilités de biovalorisation : revue de l’art

Résumé                                                                                                 Les effluents de cave constituent une problématique environnementale qui reste à ce jour incomplètement résolue.Après un rappel sur la réglementation, cet article aborde les caractérisations quantitative et qualitative des effluents vinicoles et expose les possibilités de valorisation qui s’avèrent très prometteuses et qui ont toutes prouvé des résultats satisfaisants. La nature organique de ces rejets, autorise le recours aux procédés biologiques basés sur l’utilisation de microorganismes et du métabolisme aérobie ou anaérobie.L’efficacité du traitement en aval et le rendement épuratoire sont liés à la quantité et la qualité de pollution à traiter. Il est souhaitable d’envisager des filières d’épuration préservant les ressources énergétiques existantes, en intégrant ce paramètre dans la décision de choix de la technique de traitement, ou en réfléchissant à l’emploi des énergies renouvelables dans les processus d’épuration des effluents de cave

Experimental Investigation of Tip Vortex Meandering in the Near Wake of a Horizontal-Axis Wind Turbine

The aerodynamic optimization of horizontal axis wind turbine has became one of the most important challenge in the renewable energy field. Over the past few years, many researchers have drawn more attention to the physical processes of the wind energy conversion and precisely the identification of the main causes of energy losses. This paper presents an experimental investigation of near wake dynamics for a model horizontal axis wind turbine in a wind tunnel. The coherent structures downstream of the rotor were studied for different tip speed ratios using the Particle Image Velocimetry (PIV) technique. The influence of the tip vortex meandering was discussed and analyzed using the Proper Orthogonal Decomposition (POD) method. The high-energy modes show that radial meandering is the most energetic source of perturbation in each tip vortex sub-region. The energy fraction of these modes increase gradually during the development of the helical tip vortex filament, which confirm the growth of vortex wandering amplitude in the near wake

Proper Orthogonal Decomposition Analysis of an Airfoil Performances under a Small Vortical Gust

This paper investigates the performance of a non-symmetric airfoil in a perturbed flow for a low Reynolds number by creating small vortical structures. A newly designed two-dimensional numerical tool is used to examine the interaction between the NACA 23015 airfoil and the vortex shedding from a square cylinder. Different airfoil position ratios are numerically simulated concerning the square cylinder G/D (D: square cylinder diameter), the channel centerline T/d (d=D/2), and the vortices scale size D/c (c: airfoil chord length). Results show that the maximum values of the lift and drag aerodynamic coefficients are influenced by the airfoil’s lateral and longitudinal positions. The Proper Orthogonal Decomposition (POD) method is used to identify the most energetic flow structures. For all simulated scenarios, it was found that the first two modes reflect the dominating coherent structures in the flow field. The results also show that a leading-edge vortex is formed over the airfoil. The observed phenomena of symmetric and antisymmetric shedding vortex mechanisms essentially depend on the lateral distance of the airfoil T/d and the vortex scale size D/c. However, the spectral analysis demonstrates that the shedding frequency mainly depends on the gap distance G/D

Wind energy in the Gulf of Tunis, Tunisia

This paper presents a study of wind resource in the Gulf of Tunis. During 2008, an experimental measurement of wind speed and wind direction at 20 m and 30 m, were conducted using a 10-min time step. The statistic treatment of results permitted us to evaluate the most characteristics of wind energy in the studied site. An extrapolation of wind speed is, also, carried out using the deduced power law exponent. The annual production of the wind turbine Enercon E82 is estimated at a height of 100 m above ground level. The obtained results can be used to perform wind park project and confirm that the Gulf of Tunis has promising wind energy potential.Mean wind speed Weibull distribution Wind power potential Wind rose Turbulence intensity Wind turbine

Measurement of the V2I massive radio channel with the MaMIMOSA sounder in a suburban environment

This paper presents the first V2I channel sounding campaign with the real-time massive MIMO radio channel sounder named MaMIMOSA. This equipment has been jointly developed by ULille (FR) and UGhent (BE) for 5G V2X applications. The system is equipped with a massive 64-antenna array for Tx whereas up to 16 individual antennas can be deployed for Rx. The MaMIMOSA hardware and software capabilities allow to freely adapting the sounding parameters to the investigated scenario demonstrating its versatility and flexibility. Radio channels were measured at 5.89 GHz with 80 MHz bandwidth at the ULille campus using with mean vehicle speed of 30 km/h. In addition to this suburban mobility scenario, Obstructed Line-Of-Sight static radio channels were collected for a roadside to parking setup to study the influence of vegetation. Very preliminary Doppler characteristics are reported from the measured radio channels