Dr REZGUI Mohamed-Ali Assistant-Professor

This paper is focused on preliminary results obtained in the VENTURAS (VENTo: Una Risorsa Altamente Sfruttabile or 'wind: a highly exploitable resource') project, funded by the Italian Environmental, Land and Sea Protection Ministry, within a call for the funding of research projects aimed at improving the energy efficiency measures and the use of renewable energy sources in urban areas. The scope of the project is to develop an innovative propeller concept to improve the efficiency and the working capabilities of micro wind turbines, widening the range of the wind speed for which the turbine can transform energy effectively and safely. This new propeller concept is based on a variable pitch blade, which has morphing capabilities that enables the control system to select the optimum twist law along the blade, to optimize the efficiency also in non-nominal conditions. The final layout identified for the proposed wind turbine will be presented; the pylon contains the power sup...

International Journal of Electrical and Computer Engineering (IJECE), 2017

The article describes multidisciplinary design process of high-performance electric generator for advanced aircrafts by analytical methods and computer modeling techniques (electromagnetic, thermal and mechanical calculations). New technical solutions used in its development are described. The main ideas are revealed of the method of EG voltage stabilization we used. To improve the heat dissipation efficiency, we have developed a new cooling system, and provide its study and description in this paper. The advantages of this cooling system include the fact that EG is made with dry, uncooled rotor. This allowed eliminating additional pumps, and significantly reducing the size of CSD. According to the results of our study, we created an experimental full capacity layout, and its studies are also provided in this paper.

The article proposed an algorithm for generating sets of blades used for wind generator's propeller. The main goal is to design and realise a 1 kW wind generator that can work with high efficiency at the specific wind condition from Romania. Since a big amount of time the wind speed is lower, usually under 3 m/s it was designed a propeller that has a starting speed of 2.7 m/s. A low Reynolds number airfoil is selected regarding to the low working speed of the propeller's generator. This airfoil is considered the reference. Based on the airfoil, the necessary calculations are made in order to obtain all the points that will form the blade. It was analysed the influence of tip speed ratio, lift coefficient and attack angle upon the blade profile and generate two sets of blades. A Pascal software was written with which can directly build the NC files. In order to correct the influence of the radius of the cutter upon the final shape of the blade, was also implemented a procedur...

Man always tried to extract as much energy as possible from the freely available energy sources in this world. One such attempt is the building of the turbine, which converts the fluid energy into mechanical energy, which is later converted into electrical energy. Due to the constant increase in the demand for this energy, the performance of these turbines mattered a lot and hence various types and designs of turbines were developed. One such turbine is the bladeless (Tesla) turbine. Many analytical studies have been carried out on this turbine but very limited information is available on the actual test results. In this paper, an attempt has been made to fabricate a turbine and study the effect of various parameters on the turbine's performance. The observations are plotted. Few parts and parameters are kept constant while the others are varied during the testing process. Maximum rpm which was 25,324 was observed at six bar pressure, two exhaust holes on each flange and operating with four-disc rotor assembly.

2016

Zenodo (CERN European Organization for Nuclear Research), 2022

Theoretical algorithms, such as computational fluid dynamics (CFD), blade elementary method (BEM) theory, and the vortex wake system (VWS) have been implemented in the design of aerodynamic wind turbines. On these theoretical methods, the (BEM) theory proved to be the best method in optimising HAWT blades and is thus the most commonly used approach in modelling and constructing small wind turbine blades. This paper will primarily focused on designing and optimizing the type of aerofoil required for improving the pitch angle of the rotor blades, and for determining the number of blades necessary to optimise the power output at various wind speed using BEMT. A NACA-4412 type aerofoil was chosen as the departure point for the blade design. Various pitch angles of 6°, 10° and 12° were chosen at an optimum angle of attack of 5°, 7° and 9°. A blade radius of 0.8-1.0 m and chord length of 0.08-0.1 m were subsequently chosen for Designs 1, 2 and 3 respectively at various low wind speeds. At average wind speed of 0-2.3 m/s (8.28 km/h), 3-blade, 5-blade and 7-blade sets were designed and optimized for performance. During the design of the wind turbine blades, it was predicted that at various wind speeds, the rated output would be 7.5 W, 20 W and 40 W respectively Design 1, 2 and 3. The results for Design 1, with a blade radius of 0.85 m, a chord length of 0.06 m near the rotor hub, with a pitch angle of 6° at the rotor hub and a tapering off to about 1° at the blade radius tip of the blade, produced a maximum output power of 8.2 W at 4.2 km/h wind speed, and Design 2, with a blade radius of 0.95 m, a chord length of 0.08m near the rotor hub, with a pitch angle of 10° near the rotor hub and a tapering off to 1° at the blade radius tip of the blade, yielded a maximum output power of 12,5 W at 4.2 km/h wind speed and lastly Design 3, with a blade radius of 1m, a chord length of 0.1m near the rotor hub, with a pitch angle of 12° near the rotor hub and tapering off to 2° at the blade radius tip of the blade, generated a very useful power output of 39.5 W during testing. The maximum power output was achieved at an average wind speed of 1.17 m/s (4.2 km/h).

The Journal of Engineering, 2019

This study describes the design, construction, and testing of an aero-engine starter-generator and its associated power electronic converter. A high-speed, permanent magnet machine and a dual-channel machine-facing converter with an electrical power offtake rating of 95 kW have been developed for a small civil turbofan application. The study also describes the more-electric architecture into which the machine and converter are integrated and reviews the multi-faceted performance specification, which is a common feature of machines of this type.

IJSTE - International Journal of Science Technology & Engineering, 2018

Wind turbines are becoming popular in the renewable energy world. Development in the wind turbines are being made to make it more reliable and effective but the problem is with the transmission of power from the generating plant to the remote (off-grid) locations. Many developing countries have very limited power distribution to rural locations, and small wind turbines have proven to be an effective means of bringing electricity to many people and villages in remote locations. From here we define the main objective of the project is to design and develop a small scale wind turbine to serve as an effective means of generating electricity in remote locations. Savonius wind turbine is one of the kinds of vertical axis wind turbine in which we have made some design alterations to develop Aeroblade Savonius wind turbine. Aesthetic, economic and functional requirements are incorporated into it in order to make it a part of the sustainable consumer products. Other than the rural areas, installation of this turbine in schools, parks, offices and anywhere required will considerably reduce the electricity bill. This turbine is designed as an aid to the energy consumption of the product in which it is incorporated, maintaining the advantages of a conventional Savonius rotor as self-starting, easy manufacture and maintenance and able to integrate into its environment.

International Conference on Electrical Engineering Design and Technologies, ICEEDT 2007, Hammamet, Tunisia, 2007

In this paper, the objective of this study is to evaluate the wind potential of the site Sidi Daoud, at 30m height above ground level, by three statistical methods (meteorological, Weibull and Rayleigh), to identify the characteristic parameters of aerogenerator AE-32 and to determine its energetic efficiency on site. Index Terms-Tunisia, Wind farm of Sidi Daoud, Wind energy, Meteorological distribution, Weibull method, Rayleigh method, Aerogenerator AE-32, mean efficiency. 1. NOMENCLATURE V Wind speed (m/s) F(V) Cumulated frequency f(V) Occurrence frequency n Number of wind speed classes Vm Mean speed (m/s) Vf Most frequent speed (m/s) Ve Most energetic speed (m/s) Pd Power density at Betz limit (W/m²) Ed Available energy at Betz limit (kWh/m²/year) Eu Usable energy (kWh/m²/year) Er Recoverable energy (kWh/m²/year) Ps Electric power on the aerogenerator outlet (kW). ηd Mean efficiency relating to the available energy ηu Mean efficiency relating to the usable energy η Global mean efficiency ηm Gearbox efficiency (96%) ηg Generator efficiency (96.2%) Cp Power coefficient λ Specific speed N Rotational speed of rotor (tr/mn) A Weibull scale factor (m/s) K Weibull shape factor ρ Air density (1.225 kg/m 3) σ(M,W,R) Standard deviation calculated from the meteorological, Weibull and Rayleigh methods (m/s)

International Journal of Engineering & Technology

The main objective of this study is to increase the aerodynamic efficiency of turbine mounted novel wing. The main motive behind this work is to reduce the drag by attaining the positive velocity gradient and generate power by converting the stagnation pressure which also acts as emergency power source. By using the energy source of free stream air, Mechanical energy is converted into electrical energy. The obtained power is presented in terms of voltage generated at various angles of attack with different Reynolds number. Experimental analysis is carried out for NACA4415 airfoil at various angles with respect to free stream ranging from 0deg to 30deg from laminar to turbulent Reynolds number. The results were obtained using the research tunnel at IARE aerodynamic facility center. The aerodynamic advantage of this design in terms of voltage is 9.5 V at 35m/s which can be utilized for the aircraft on board power systems.