LABORATORY OF AERODYNAMICS - GENERAL

The Laboratory of Aerodynamics belongs to the Fluids Section of the Mechanical Engineering Department of the National Technical University of Athens (N.T.U.A.) which is the oldest Technological Institute in Greece. It is housed in a new building of 8800 square meters, completed in 1980. The size and the broad range of equipment permits the fulfillment of its basic goals, which are the good training of students, the pursue of basic and applied research and technical consulting to interested companies.
	General view of the first level of the Lab.
	These services are offered not only to the public or private sector of Greece, but are open to the European market too, through participation of the Laboratory in research projects funded by the European Community or other European Companies.
General view of the second level of the Lab.
The Laboratory has four faculty members as research leaders and more than fifteen postgraduate students, working in the Laboratory in a full time basis, conducting Ph.D.-level research, whereas a number of diploma theses are performed each year on various aspects of aerodynamics. There is also the Laboratory's secretariat, the machine shop personnel and a technician responsible for the experimental equipment.
	The test section No.1 of the large wind tunnel.

General plan of the wind tunnel.

	The basic experimental facility of the Laboratory is the large, closed circuit, subsonic wind tunnel. This is a facility of high measuring accuracy and for a broad range of applications. It is powered by a seven blade axial fun; the motor is 350 HP and it is thyristored controlled so as continuous control of wind speed can be achieved. The total length of the tunnel is approximately 32 meters and has three closed test sections. In the first test section the maximum wind velocity is 70m/s and is equipped with a high accuracy six-component balance for the measurements of air forces between -1000 to 5000 Nt. Appropriate for both basic and applied research on airfoils, wings, fuselages, airplanes models, light or heavy vehicles and certification on aircraft modifications.
Flow visualisation around a 1/18 scaled car model.
Aerodynamic study of an electric vehicle designed in the Laboratory.	Research of the aerodynamic coefficients,the velocity field and the pressure distribution around a 1/5 scaled car model.

Research of the aerodynamic coefficients, static stability characteristics and the tank trajectory after release from an airplane model.
The second test section with maximum wind speed of 18 m/s, is equipped with a remotely controlled turn-table floor and a three directions motor-driven, remotely controlled traversing mechanism. This section is appropriate for experiments related to Industrial Aerodynamics such as flow visualization and forces exerted on buildings, greenhouses, bridges and cooling towers, studies of siting of wind generators, studies on environmental pollution, studies of the gases dispersal from chimneys of buildings and thermoelectric power stations etc. In the third section which is the largest, the maximum wind speed is 12m/s and is suitable for aerodynamic studies on propellers, wind generator blades, fans etc.
	A study on the aerodynamics of tractor- trailer trucks.
Research on the velocity and turbulence levels on the deck of frigate "ELLI".	Research on the dispersion of the effluents from the stack on the deck of a ship.

	The Laboratory is also equipped with three small wind tunnels of typical test section 30cm by 40cm and a wind speed of 40 m/s. These tunnels are used mainly for educational purposes and for basic research on smaller size models. The Laboratory is equipped with a Laser-Doppler apparatus for measuring fluid velocities with the use of laser beams, based on the Doppler frequency shift of the optical signals. The LDA technique has been used in pulsating flows in closed ducts of small dimensions (expanding or contracting and, branching ducts) in which the blood circulation is simulated. The method is used also in other branches of biomedical technology. There are also hot-wire anemometers and various types of Prandlt and Pitot tubes, flowmeters etc. All measurements are led on line via analogue to digital converter to a laboratory computer for data reduction.
Aerodynamic study of a wind generator (2.5m in diameter) installed inside the test section No.3 of the wind tunnel. Research has been conducted on the aerodynamic performance of the machine and on the flow field development using hot-wire anemometry.
Research on the aerodynamic performance of a vertical axis wind generator of Savonious type.	Aerodynamic study of a vertical axis wind generator of Darrieus type.
Aerodynamic study and development of a wind generator, 20m diameter installed in the Greek island of Skyros.	Research on the wind circulation in the Attika plane and on the pollutant transport to Athens.
	In the Laboratory complex exists also supplementary facilities which support the experimental activities. Such facility is the machine shop which is equipped with lathes of high precision for the accurate construction of the special equipment required for the experiments as for example airfoil models, airplane wings, metal propellers etc. There is also the model shop which is equipped with typical machines for wood curving and with a pantographic machine in which special models such as ships, fuselages, vehicles etc can be constructed.
Model of an arterial bifurcation for L.D.A measurements and the pulsing arterial flow simulator.	Research on the wind field of the Olympic Velodrome of Athens.
	Finally the electronic and electric shop, the staff of which has developed special apparatus for the automatic execution of experiments, for connecting the instruments to the computers via various protocols and for maintaining the rather complex electronic hardware of the laboratory in operation mode.
Investigation of the wind enviroment in the Athens Olympic Center tennis courts.
Research on the pollutant dispersion around the Megalopolis Thermoelectric power station.