Laboratory of Aerodynamics - NTUA · Laboratory of Aerodynamics Research Activities Theoretical External Aerodynamics and Aeroelastic Analysis Aerodynamic and Aeroelastic analysis

Laboratory of Aerodynamics


The Laboratory of Aerodynamics belongs to the Fluids Section of the school of

Mechanical Engineering of the National Technical University of Athens (N.T.U.A). It is

housed in a building of 8800 m2 completed in 1980. Main objective of the educational

and research activities of the Laboratory of Aerodynamics is the experimental and

theoretical (computational) analysis of flow problems that cover a broad range of

applications. In this context, problems of external aerodynamics with application to

fixed wing aircrafts, helicopters, wind turbines, buildings etc. as well as other

fluid/structure interaction problems, flows in micro-channels and bio-fluid mechanics

problems are dealt with.

The Laboratory of aerodynamics since its foundation has actively participated in

several Research projects, National and International (especially European). The

continuous and systematic research activity on various research topics/applications

has led to a numerous of Journal and Conference publications. In parallel the

laboratory is also active in providing consultancy services to the public or private

sector (organizations, utilities and enterprises).

The laboratory has two faculty members and more than 15 researchers, Ph.D

students, technicians working in a full time basis.

Experimental Facilities

The main experimental facility of the Laboratory of Aerodynamics is the low speed

(subsonic) closed circuit wind tunnel (maximum speed 60 m/s). It is high precision

measuring facility which can be used in a broad range of experimental applications. It

is powered by a seven blade axial fan of 350 hp.

The total length of the wind tunnel is 32 m and it consists of 3 test sections:

Width (m) Height (m) Max Speed (m/s)

4.5 3.5 9.5

3.5 2.5 17.0

1.8 1.4 60.0

The maximum speed in the smallest section is 60m/s and the turbulence level 0.2%.


General arrangement of the wind tunnel

Testing of a HAWT model in the 4.5x3.5m section

The first section (largest) is suitable for

testing small propellers, wind turbine

rotors and fans


The second is equipped with a remotely

controlled turn table floor and a three

directions motor driven remotely

controlled traversing mechanism. This

section is suitable for industrial

aerodynamics applications such as flow

visualizations and assessment of

aerodynamic forces exerted on buildings

(urban areas buildings, industrial

complexes, green houses, bridges and

cooling towers), wind turbines siting

applications, environmental pollution

studies, studies of the gases dispersal

from chimneys of buildings and

thermoelectric power stations etc.

Testing of an aircraft in the 1.8x1.4m section

Investigation of the wind environment in Athens Olympic centre (measured in the 3.5x2.5m section)

Pollutant dispersion around Megalopolis Thermoelectric station (measured in the 3.5x2.5m section)

The third section is suitable for basic and

applied research applications. It can be

used for testing 2D aifoils, aircraft wings,

fuselages, model aircrafts, light and

heavy vechicles. It is equipped with a

high accuracy six-component balance

for the measurement of the airloads.


The following measuring capabilities are provided:

Load measurements are performed using a 6 component balance and a 6

component load pad.

A PIV system is available, allowing velocity field measurements on a plain

Localised flow velocity measurements are performed by means of hot wire

velocimetry and 7 hole pitot tubes.

A Laser-Doppler apparatus is available 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

Multiple channels pressure scanners are available for measuring static

pressure distributions on aerodynamic bodies.

Flow visualizations are performed using smoke and a Laser source, liquid

crystals and ΤiΟ2-oil compound.

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.

In the Laboratory complex supplementary facilities also exist that 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.


Computational Facilities Substantial computational power is available in the Laboratory of Aerodynamics consisting of:

A blade server with 8 blades. Each blade includes 2 Intel Xeon quad-core processors E5420 (2.5 GHz, 12MB cache), making a total of 64 cores, suitable for parallel processing. Each processor has 8 GB RAM

4 dual-core Intel Xeon processors E7520 (3.6 GHz, 2MB cache) making a total of 8 cores, suitable for parallel or serial processing. Each processor has 8GB RAM

4 dual-core Intel Pentium processors D945 (3.4 GHz, 4MB cache) making a total of 8 cores, suitable for serial or parallel processing. Each processor has 2GB RAM.

Many individual processors capable of serial processing

The computer power available gives the possibilty of treating complex aerodynamic problems.

Blade server with 8 bldes


Research Activities

Theoretical

External Aerodynamics and Aeroelastic Analysis

Aerodynamic and Aeroelastic analysis of Helicopter, Wind Turbine, Tiltable and

conventional Aircraft rotors as well as combined wing/rotor interaction problems are

some of the research topics of interest. Substantial research effort as been expent in

the above topics during the last 15 years through the participation of the laboratory in

many EU and National research projects.

In the field of External Aerodynamics the following modeling capabilties are available:

3D free wake vortex type lifting surface and panel methods

2D and 3D finite volume methods (Reynolds Averaged Navier-Stokes, Euler

compressible solvers)

In Aeroelastic problems the modeling of the structural dynamics is based on multi-

body dynamic analysis combined with FEM approximation of the flexible

components.

Tools

The in house code GENUVP is used in the aerodynamic analysis of rotor/wing

problems. It is a free wake panel code which is based on a vortex particles (vortex

blobs) approximation of the wake. Main advantage of GENUVP, especially due to the

particle approximation of the wake, is its capability of easily treating complex

geometries and solid-wake interaction problems.

The in house code GAST is used in the aeroelastic analysis of rotor and combined

rotor-pylon problems. It is servo-aero-elastic tool which besides the structural

dynamics is also able to model the controls of the system. In the modeling of the

flexible bodies higher order beam models are applied using a FEM discretization. It

can be used for non linear time domain analysis and linear eigenvalue stability

analysis


Full Helicopter Aeroelastic Modelling. Development and interaction of Main Rotor, Tail Rotor and Horizontal Stabilizer wakes.

Measurements Predictions

Comparison of the predicted downwash velocities of a Helicopter Main Rotor against measurements. In the figure also the predicted tip vorticies traces and their footprint on the measureing planes are shown.

(Measurements conducted under the EU funded proect HELINOVI (Contract Number G4RD-CT-2001-40113) at the DNW LLF using PIV technique)


psi

87

%C

N

0 90 180 270 360

0

0.2

0.4

0.6

0.8

1

GENUVP

Measurements

Level Flight at 33m/s, MR, r/R=0.87

psi

75

%C

N

0 100 200 3000

0.2

0.4

0.6

0.8

1

NTUA

Main Rotor, r/R=0.75

psi

97

%C

N

0 100 200 300-0.2

0

0.2

0.4

0.6

0.8

1

NTUA

Main Rotor, r/R=0.97

psi

70

%C

NM

2

0 100 200 300-0.1

0

0.1

0.2

0.3

0.4NTUA

Tail Rotor, r/R=0.70

psi9

7%

CN

M2

0 100 200 300-0.1

0

0.1

0.2

0.3

0.4

NTUA


psi

80

%C

NM

2

0 100 200 300-0.1

0

0.1

0.2

0.3

0.4NTUA

Measurements


psi

87

%C

N

0 90 180 270 3600

0.2

0.4

0.6

0.8

1

GENUVPMeasurements

6deg, descent 33m/s, MR, r/R=0.87

Comparison of predictions of the normal force coefficient CN at r/R=0.87 of a Helicopter Main Rotor blade against measurements. (Left) level flight at 33 m/s, (Right) 6(deg) descent at the same speed.

psi (deg)

fla

pw

ise

be

nd

ing

mo

me

nt

(Nm

)

0 45 90 135 180 225 270 315 360-150

-100

-50

0

50

100

150

200

250

meas. (green)

meas. (red)

predictions MR+TR

Main Rotor (r/R=0.0300) / Case 851 (12.3 m/s)

psi

fla

pw

ise

be

nd

ing

mo

me

nt

(Nm

)

0 45 90 135 180 225 270 315 360-40

-30

-20

-10

0

10

20

30

40

50

meas. (green)

meas. (blue)

meas. (red)

predictions MR+TR


psi (deg)

fla

pw

ise

be

nd

ing

mo

me

nt

(Nm

)

0 45 90 135 180 225 270 315 360-40

-30

-20

-10

0

10

20

30

40

50

meas. (yellow)

meas. (green)

meas. (blue)

meas. (red)

predictions MR+TR


psi (deg)

fla

pw

ise

be

nd

ing

mo

me

nt

(Nm

)

0 45 90 135 180 225 270 315 360-40

-30

-20

-10

0

10

20

30

40

50meas. 1

meas. 2

meas. 3

meas. 4

predictions

azimuth angle (deg)

fla

pw

ise

de

fle

ctio

n/R

*10

0

0 45 90 135 180 225 270 315 360

-2

-1

0

1

2 meas. (blade 1)

meas. (blade 2)

meas. (blade 3)

meas. (blade 4)

predictions

SPR2 (flight speed=50.9m/s), r/R=0.23

azimuth angle (deg)

fla

pw

ise

de

fle

ctio

n/R

*10

0

0 45 90 135 180 225 270 315 360

-2

-1

0

1

2


azimuth angle (deg)

fla

pw

ise

de

fle

ctio

n/R

*10

00 45 90 135 180 225 270 315 360

-2

-1

0

1

2


azimuth angle (deg)

fla

pw

ise

de

fle

ctio

n/R

*10

0

0 45 90 135 180 225 270 315 360

-2

-1

0

1

2


azimuth angle (deg)

fla

pw

ise

de

fle

ctio

n/R

*10

0

0 45 90 135 180 225 270 315 360

-2

-1

0

1

2

meas. (blade 1)

meas. (blade 2)

meas. (blade 3)

meas. (blade 4)

predictions

(Left) Comparison of predictions of the root flawise bending moment of a Helicopter Main Rotor blade against measurements (measurements for all 4 blades are presented – Level Flight case at 12.3 m/s)

(Right) Comparison of predictions of the tip flawise deflection of a Helicopter Main Rotor blade against measurements (measurements for all 4 blades are presented – Level Flight case at 50.9 m/s) (Measurements conducted under the EU funded proect HELINOVI (Contract Number G4RD-CT-2001-40113) at the DNW LLF)


-10 -5 0 5 10

u

31

29.5

28

26.5

25

23.5

22

20.5

19

17.5

16

14.5

13

11.5

10

8.5

7

5.5

4

2.5

1

-0.5

-2

Modelling of the flow around a Helicopter main Rotor in an open jet wind tunnel

Full Aeroelastic Modeling of the Rotor/Wing interaction problem using GENUVP free wake code and GAST in a TiltRotor configuration.


0 50 100 150 200 250 300 350

speed (kts)

0

5

10

15

20

25

30

35

40

fre

qu

en

cy

(Hz)

wing beam

wing chord

wing torsion

rotor gimbal reg

rotor gimbal prog

rotor flap col

rotor flap react

rotor lag reg

rotor lag prog

rotor lag col

rotor lag react

0 50 100 150 200 250 300 350

speed (kts)

-20

-10

0

10

20

30

40

50

da

mp

ing

(%)

Stability Whirl Flutter predictions for TiltRotor confiuration in Level Flight.


Full Wind Turbine Aeroelastic Modeling using GENUVP free wake code. Visible is the wake reaction to the vibrations undergone by the blade

Wind Turbine wake developement in the case of a high yaw misalignment of 32(deg)


Wind Turbine wake developement in the case of an extreme shear (shear exponent

0.55). Wake highly skewed, significant downwash velocities of the wake near the

rotor plane.

Load predictions for a 500kW wind turbine and comparison against measurements

(mean and fatigue)

(Left) Azimuth variation of the flapwise bending moment at the blade root

(Right) Cumulative spectrum of the fatigue loads (rainflow counting)


wind speed (m/s)

da

mp

ing

inlo

gd

ecre

me

nt

(%)

6 8 10 12 14 16 18 20-5

0

5

10

15

20

wind speed (m/s)

fre

qu

en

cy

(Hz)

6 8 10 12 14 16 18 201.4

1.5

1.6

1.7

1.8

1.9

2 GAST+RAFT lin

GAST+RAFT nolin (pitch excit.)

GAST2+GENUVP (pitch excit.)

measurements (OMA)

wind speed (m/s)

fre

qu

en

cy

(Hz)

6 8 10 12 14 16 18 201.4

1.5

1.6

1.7

1.8

1.9

2 GAST+RAFT lin

GAST+RAFT nolin (pitch excit.)

GAST2+GENUVP (pitch excit.)

measurements (OMA)

wind speed (m/s)

da

mp

ing

inlo

gd

ecre

me

nt

(%)

6 8 10 12 14 16 18 20-5

0

5

10

15

20

Stability predictions and comparison with measurements for a 2.75 MW variable speed, pitch regulated wind turbine (Left) Predictions of the 1st lead-lag regressive mode frequency (Right) Predictions of the 1st lead-lag regressive mode damping

Computational grid around a wind turbine blade


Pressure coefficient distribution around a 2D airfoil. Computational performs with the in-house RANS solver.

Unsteady compressible subsonic flow prediction about a 2D airfoil. Computations performed with an in-house Euler Solver.


Internal Aerodynamics/Combustion 3D steady and unsteady, turbulent flow simulation in a complex cylinder 4 - valve head configuration of an 4-X gasoline internal combustion engine. The governing Navier - Stokes conservation equations of the flow field are numerically solved on a three dimensional generalized curvilinear non - orthogonal grid, using Cartesian velocity components, following the finite volume approximation and a pressure correction method. Turbulence is simulated by a two equation transport model. A single hole, low pressure, standard type injection unit, typical for gasoline engines, was supposed to inject fuel in one of the inlet ports. The spray simulation is based on the Discrete Droplet Method (DDM). According to this method, the spray is represented by a number of droplet parcels; each of them contains a large number of identical droplets which do not interact with each other. Several submodels are used in order to take into account the complex phenomena that are associated with the spray injection. Many cases have been considered, with different spray injector position and different spray droplet diameters, in order to compare the droplets location after the injection and to quantify charge stratification. The results indicate that directing the injector axis into the inner quarter of the valve results in a dense spray formation that can lead to charge stratification.


Wind farms wake analysis Analysis of wind farms wake effects using 3D CFD RANS solvers. Tool An inhouse solver has been developed (NTUA-3DNS) with the following features:

The model solves the 3D Reynolds averaged incompressible Navier-Stokes equations (RANS) on a Cartesian grid using the k-ε turbulence closure model.

Wind turbines are accommodated in its grid as momentum sinks (pressure jumps) representing the axial force applied on the rotor disk that is in turn evaluated from the given thrust coefficient curve.

p/(1/2Uo 2)

πτώση

πίεσης

k/Uo2

z/D

u/Uo

y/D

Typical velocity, turbulence and pressure behavior in a wind farm

pressure

jump


The offshore Horns Rev wind farm layout together with the numerical grid/domain used for 3 wind turbine rows (30 wind turbines) operating in westerly wind directions

(a) (b)

15D

10D

5D 20D

(c)


Model results compared with measurements of power output ratio of wind turbines in the same row (three rows) to the power output of the first turbine in the row.

270o±2.5

275o±2.5


Helicopter Aeracoustics

Calculation of acoustic pressure time series and contours

Utilization of the Ffowcs Williams-Hawkins equation in Succi or Farassat formulation

HELINOVI experiment - DNW wind tunnel (EU funded project G4RD-CT-2001-40113)

Measurement plane

Microphones position


Calculation method 1:

Loads at thin blades calculated using free wake aerodynamic code GENUVP

Acoustic pressure time series using Succi formulation

Calculation method 2:

Blade local incidence calculated using free wake aerodynamic code GENUVP

Pressures on the blade surface calculated using a potential 2D airfoil solver for each blade section

Acoustic pressure time series using Farassat formulation

Case 2: Forward flight, 60m/s - Method 1

Measurements performed at DNW wind tunnel under EU funded project Helinovi


Case 10: Forward flight, 60m/s, Reduced tip speed - Method 1



Case 5: Descent flight, 33m/s, Methods 1&2



Design of Airfoils and Rotors Substantial research effort has been put in designing new airfoil shapes and blade geometries (intended for wind turbine rotors). The lab of aerodynamics has aerodynamically designed two wind turbine blades one 19m long and one 30m long in the framework of European and National projects aimed at developing blades of Greek technology. The first blade has been tested on a prototype 500 kW wind turbine installed at the test station of CRES (Greek Centre for Renewable Energy Sources) in Lavrio. The design of new optimized airfoil shapes and blade geometries is based on evolutionary methods (genetic optimization methods)

Genetic Optimization approach used in designing airfoil shapes

Assessement of the new airfoil designs is carried out through wind tunnel tests at NTUA wind tunnel facility


Create new airfoils

for every

design thickness

Create new airfoils

for every

design thickness

new blade designnew blade design

Terminate when no further

significant improvement

occurs

Terminate when no further

significant improvement

occurs

GA

for airfoil design

GA

for airfoil design

AIRFOIL

DATABASE

AIRFOIL

DATABASE

GA

for blade design

GA

for blade design

operational angles of attack for every relative thickness

UpdateUpdateRandom

Selection

Random

Selection

Blade Design Optimization Loop

Comparison of the power

curves obtained using

standard NACA 63 series

and optimized airfoil shapes


Experimental Activites

Fundamental Fluid Mechanics-Aerodynamics research experiments

Measurements on Axisymmetric body

Velocity measurements using a seven hole pitot tube

Wall shear stress measurements (Use of hot film)

-100.00 -80.00 -60.00 -40.00 -20.00 0.00 20.00 40.00 60.00 80.00

-20.00

0.00

20.00

40.00

60.00

80.00

100.00

Measured cross-flow velocities (using 7 hole Pitot tube). Lee-side of axisymmetric body

Flow visualization (TiO2-Oil)

Flow visualization (liquid crystals)


Square fuselage at roll and pitch

Visualisation of vortices using smoke

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 100.00 110.000.00

10.00

20.00

30.00

40.00

50.00

Square fuselage.Cross flow velocity field


Delta wing wake development

Tip vortices visualization using smoke

Flow visualization using smoke


Vibrating Cylinder

Wake velocity measurements using hot wire

Aerodynamic force measurements (use of strain gauges)


Flow about a moving square prism

Διάγραμμα Cy σσναρτήσει της γωνίας πρόσπτωσης για τατύτητες 10.55 ,11.53 και 15,78 m/sec

(Cy=0 για α=-2)

-1,5

-1

-0,5

0

0,5

1

1,5

2

-40 -30 -20 -10 0 10 20 30 40

Γωνία πρόσπτωσης

Cy

15.78 m/sec

11.53 m/sec

10.55 m/sec

Ο αριθμός Strouhal σσναρτήσει της γωνίας πρόσπτωσης

για τατύτητα 8.64 m/sec

0,15

0,155

0,16

0,165

0,17

0,175

-5 0 5 10 15 20 25 30 35

Γωνία πρόσπτωσης

Αρ

ιθμ

ός S

tro

uh

al

Lift coefficient for square prism Strouhal number versus angle of attack

Flow visualization


Pitching airfoil

Velocity measurements using PIV

Velocity field measured using PIV


Mixing of two air streams (Use of smoke and stroboskope)


Flow Control Experiments Flow control using pulsating jets. A backward facing step

slot

holes


flow

0

1

2

3

4

5

6

7

0 10 20 30 40 50 60

Z(c

m)

0.3cm

1cm

2cm

3cm

4cm

5cm

6cm

7cm

8cm

9cm

10cm

11cm

12cm

13cm

15cm

17cm

19cm

21cm

23cm

25cm

27cm

29cm

31cm

33cm

edge

slot

Hot-wire streamwise velocity profiles. No jets

flow & Jets

0

1

2

3

4

5

6

7

0 10 20 30 40 50 60

Z(c

m)

0.3cm

1cm

2cm

3cm

4cm

5cm

6cm

7cm

8cm

9cm

10cm

11cm

12cm

13cm

15cm

17cm

19cm

21cm

23cm

25cm

27cm

29cm

31cm

33cm

edge

slot

Hot-wire streamwise velocity profiles. Use of airjets


Aeronautical and wind energy applications related experiments A rectangular fuselage-high wing configuration

Pressure measurements on model surface


Biplane configuration

Not joined wing tips

Joined wing tips


Airfoil steady polars assessment

For 2D airfoils testing the smallest (high

speed and low turbulence) test section is

used.

The dimension of the wing models are

defined based on the maximum tunnel

speed and the geometry of the section.

So a total wing span of 1.40m is

available (for wall to wall measurements)

while the chord length is usually set to

0.5-0.60m in order to compromise

between the Reynolds number and

blockage effects. Given the maximum air

velocity of 60 m/s, these chord lengths

correspond to Reynolds numbers

ranging from 2-2.4 million, which are the

highest that can be obtained for

acceptable blockage values.

The models are usually installed with a number of 50 to 60 flush top, staggered pressure taps, distributed at three different closely spaced spanwise stations, located at the middle part of the wing

For measuring the drag coefficient, total and static pressure measurements are performed in the wake using a wake rake of 0.40m wide that consists of 30 pressure probes. The rake is mounted on a traverse mechanism that scans the whole section width at a distance of 0.75 of the chord length downstream of the model trailing edge.

Airfoil tests are supplemented with CFD computations which allow validation of the measurements.


Typical results (measured and computed) for a 15% relative thickness airfoil, designed and tested at NTUA, are shown in the figures. Computations are performed with two different tools, a viscous-inviscid interaction code (f2w – FOIL2W) and a RANS code (ns), both developed in-house.

Experimental Set-Up


Small Rotors testing

The two largest sections of the wind tunnel are able to accommodate small rotors of maximum diameter of about 2 m.

Model rotors are mounted on the 6 components load pad for measuring rotor thrust and torque.

Also measurements of the power output are possible

Testing of a 3 bladed HAWT of D=2m

Testing of a 3 bladed small Darrieus rotor


Biofluid mechanics experiments

Flow study in a stent model (sharp edges)

Velocity vectors in a stent model (Use of PIV)

Velocity vectors in a stent model with rounded edges (Use of PIV)


Pulsating flow in a symmetric aneurysm. (PIV measurements)

Temperature and velocity measurements in a heated stenosis (use of liquid crystals)


Flow in a self oscillating flexible tube

PIV measurements in a self oscillating collapsible tube


Flow study in abdominal aortic aneurysm(AAA) model

Velocity Magnitude

0.21

0.19

0.17

0.15

0.13

0.11

0.09

0.07

0.05

0.03

0.01

PIV measurements in a AAA model


Study of vowel production

Measured Formants


Silicon oil Droplet deformation in castor oil (Use of PIV)

Droplet deformation


Flow study in a bileaflet heart valve (Use of PIV)


Valveless pumping

In vitro study of intra-aortic balloon pump


Personnel

Academic Staff Dimitrios S. Mathioulakis Associate Professor ([email protected])

Spyros G. Voutsinas Associate Professor ([email protected])

Administrative and Research Staff Petros Chassapoyiannis Mechanical Engineer Ph.D ([email protected])

John Prospathopoulos Mechanical Engineer Ph.D ([email protected])

Vasilis Riziotis Mechanical Engineer Ph.D ([email protected])

Technical Support Staff Stavros Telakis

Spyros Ballis


Recent Research Projects “Development of a MW scale wind turbine for high wind complex terrain sites,” (financed by DG XII-EU, contract ENK5-CT2000-328, MEGAWIND, 2001-2005).

Scope of the project was the design and construction of a 1MW wind turbine suitable for high speed mountainous complex terrain sites.

“C_WAKE: Characterisation and control of the wake of the new A3xxx aircraft” (financed by DG-XII, program Growth, contract G4RD-CT-1999-00141, 2000-2002)

The project addresses one of the most important topics in the field of Wake Vorticies, that of Characterization and Control of the wake vortex of Very Large Transport Aircrafts (VLTA). While the origin of wake turbulence is generally recognized, its physical characteristics in space and time continues to be insufficiently understood. As a result of the insufficient knowledge in wake characterization, its logical follow-on step is also lacking, that of wake control.

“Development and application of advanced optimization algorithms for the integrated electromechanical design of wind turbines” (financed by EPISEI, program Archimedes 2000-2001)

Scope of the project was the development of new optimization algorithms that consider the integrated electromechanical system of the wind turbine. In this respect the design cycle includes the aerodynamics of the rotor the dynamics of the mechanical system the dynamics of the generator and the control loop.

“5MW wind energy converter for offshore application,” (financed by DG XII-EU, contract NNE5-2000-412, 5MW offshore, 2001-2006).

Scope of the project was the design and construction of a 5MW offshore wind turbine in co-operation with the wind turbines manufacturer ENERCON.

“TILTAERO Tiltrotor Interaction Aerodynamics,” (financed by DG XII-EU, contract G4RD-CT-2001-00477, 2001-2006)

Main objective of the project was the investigation of the interaction effects that take place in Tiltrotor aircrafts with special focus on the rotor wing interaction problem.

“MEXICO Model Rotor Experiments under Controlled Conditions,” (financed by DG XII-EU, contract ENK5-CT-2000-00309, 2001-2006)

Scope of the project was the design and conduction of a small wind turbine test in the big low speed tunnel of DNW. The test was mainly focused on measuring the aerodynamic characteristics of the rotor and the wake velocities.

“KNOW-BLADE wind turbine aerodynamics and aeroelastics, closing knowledge gaps,” (financed by DG XII-EU, contract ENK5-CT-2001-00503, 2001-2004)

The project aimed at developing and evaluating advanced CFD codes for the aerodynamic and aeroelastic analysis of wind turbine rotors.


“HELINOVI – Helicopter noise and vibration reduction,” (financed by DG XII-EU, contract G4RD-CT2002-667, HELINOVI, 2002-2006).

The main focus of the project was the numerical and experimental investigation of the Helicopter dynamic loads and noise.

“ADYN – Advanced European tiltrotor dynamics and noise,” (financed by DG XII-EU, contract G4RD-CT2002-773, ADYN, 2002-2007).

Scope of the project was the assessment, through computations and wind tunnel tests of the dynamic response and the noise by the first European Tiltrotor concept.

“Aeroelastic stability and control of large wind turbines,” (financed by DG XII-EU, contract ENK5-CT2002-627, STABCON, 2002-2006).

Scope of the project was the development of new tools for the aeroelastic stability analysis of large wind turbines and investigation of the possibility of improving stability through passive and active control features

“UPWIND – Integrated wind turbine design”, (financed by DG XII-EU, contract 019945 (SES6), UPWIND, 2005).

The aim of the project is the development of the necessary know-how for the design of future large wind turbines (beyond 20MW). New aeroelastic tools are being developed capable of predicting non-linear effects due to large deflections. Also new smart aeroelastic control concepts (e.g. blade flaps) are investigated.

“AWIATOR, Aircraft wing with advanced technology operation,” (financed by DG XII-EU, contract G4RD-CT-2002-00836, 2002-2006)

To cope with the tremendous increase of some 5% per year in worldwide air traffic, the future environment of transport aircraft will be defined by new requirements: more stringent noise regulations, fees or limitations on gaseous emissions, new air traffic management, strong increase of aircraft frequency, and increased demand for passenger comfort. The design of a new aircraft has to take these requirements into account by applying new technologies. Within the project issues related to, the analysis of the far field around an aircraft (e.g. vortex hazard reducing services), the near field impact (e.g. large winglets), flow & load control (e.g. adaptive elements ) were addressed. In an integrative work package, flight clearance, harmonized ground test and flight test programmes. and the effect of single technologies and their combination on aircraft level were investigated.


List of Recent Publications

Journal Publications Huberson, S.G., Voutsinas, S.G. (2000), “Particles and Grid,” Computers and Fluids 31 (4-7), pp 607-25

Riziotis, V.A., Voutsinas, S.G. (2000) “Fatigue loads on wind turbines of different control strategies operating in complex terrain,” J. of Wind Engineering and Industrial Aerodynamics, 85 (2000), pp 211-240.

Schinas, D., and Mathioulakis, D.S., “Pulsating flow in a 90 degree bifurcation”, Journal of Fluids Engineering, Vol. 122, pp.1-7 (2000).

Nikolaidis, M., and Mathioulakis, D.S., “Axial and secondary flow study in a 90 deg bifurcation under pulsating conditions using PIV”, N, Journal of Fluids Engineering, Vol. 124, pp. 505-511 (2002).

Papaioannou, T.G., Mathioulakis, D.S., Nanas, J.N., Tsangaris, S.G, Stamatelopoulos, S.F., Moulopoulos, S.D., “Arterial compliance is a main variable determining the effectiveness of intra-aortic balloon counterpulsation”, Medical Engineering & Physics, Vol.24, pp. 279- 284 (2002).

Chaviaropoulos, P.K., Nikolaou, I.G., Aggelis K.A., Soerensen N.N, Johansen J., Hansen M.O.L., Gaunaa M., Hambraus T., Heiko Frhr. von Geyr 5, Hirsch, Ch., Kang Shun, Voutsinas, S.G., Tzabiras G., Perivolaris Y., Dyrmose, S.Z., “Viscous and aeroelastic effects on wind turbine blades. the VISCEL project. Part I:3D Navier-Stokes rotor simulations,” Wind Energy 6 (4), pp. 365-385, (2003)

Chaviaropoulos, P.K., Soerensen, N.N., Hansen, M.O.L., Nikolaou, I.G., Aggelis, K.A., Johansen, J., Gaunaa, M., Hambraus, T., Heiko Frhr. von Geyr , Hirsch, Ch., Kang Shun

, Voutsinas, S.G, Tzabiras, G., Perivolaris, Y., Dyrmose, S.Z., “Viscous and aeroelastic effects on wind turbine blades. the VISCEL project. Part II: Aeroelastic stability investigations,” Wind Energy 6 (4), pp. 387-403, (2003)

Papaioannou, T. G., Mathioulakis, D. S., and Tsangaris, S. G., “Simulation of systolic and diastolic left ventricular dysfunction in a mock circulation: the effect of arterial compliance”, Journal of Medical Engineering and Technology, Vol.27(2), pp. 85 - 90, (2003).

Tsangaris, S., Mathioulakis, D., Marinakis, G. and Kolyva, C., “Viscous flow in oscillating angulated tubes”, Acta Mechanica, Vol.160, pp. 61 - 70 (2003).

Anagnostopoulos, J. and Mathioulakis, D.S., “A flow study around a time-dependent 3-D asymmetric constriction”, Journal of Fluids and Structures, Vol.19, pp. 49 - 62 (2004).

Panaras, A., Voutsinas, S.G. (2004) “Effect of counter-rotating vortices on the development of aircraft wakes,” Aeronautical Journal 108 (1089), pp. 585-592


Riziotis, V.A., Voutsinas, S.G., Politis, E.S., Chaviaropoulos, P.K. (2004) “Aeroelastic stability of wind turbines: the problem the methods and the issue,” J Wind Energy, 2004, 7, pp 373-392.

Papaioannou, T.G., Mathioulakis, D.S., Stamatelopoulos, K.S., Gialafos, E.J., Lekakis, J.P, Nanas, J., Stamatelopoulos, S.F., and Tsangaris, S.G., “New aspects on the role of blood pressure and arterial stiffness on mechanical assistance by intra-aortic balloon pump:In - vitro data and their application in clinical practice”, Journal of Artificial Organs, Vol.28 (8), pp. 717-727 (2004).

Pantelatos, D.K., and D. S. Mathioulakis , D.S., “Experimental flow study over a blunt-nosed axisymmetric body at incidence”, , Journal of Fluids and Structures, Vol.19 (8), pp.1103-1115 (2004).

Anagnostopoulos, J., and Mathioulakis , D.S.,“Unsteady flow field in a square tube T-junction”, Journal of Physics of Fluids, Vol.16 (11), pp.3900-3910 (2004).

Papaioannou, Th. G. , Protogerou, A., Papamichael, CH., Mathioulakis, D., Tsangaris, S., Karatzis, E., Toumanidis, S., Zacopoulos, N., and Lekakis, J., “Experimental and clinical study of the combined effect of arterial stiffness and heart rate on pulse pressure: differences between central and peripheral arteries”, Clinical and Experimental Pharmacology and Physiology, Vol.32 (3), pp.210-217 (2005).

Prospathopoulos, J., Voutsinas, S.G., (2005),”Noise propagation issues in wind energy applications,” Journal of Solar Energy Engineering, ASME, 2005, Vol. 127, pp 234-241

Hansen, M.O.L., Sørensen, J.N., Voutsinas, S., Sørensen, N., Madsen, H.Aa., (2006), “State of the art in wind turbine aerodynamics and aeroelasticity,” Progress in Aerospace Sciences 42 (4), pp. 285-330.

Prospathopoulos, J., Voutsinas, S.G., (2006),”Implementation issues in 3D wind flow predictions over compex terrain,” Journal of Solar Energy Engineering, ASME, 2006, Vol. 128, pp 539-553

Prospathopoulos, J., Voutsinas, S.G., (2006),”Application of a ray theory model to the prediction of noise emissions from isolated wind turbines and wind parks,” J Wind Energy, 2006, 10, pp 103-119.

Manopoulos, Ch., Mathioulakis, D.S., and Tsangaris, S.G., “One dimensional model of valveless pumping in a closed loop and a numerical solution”, Journal of Physics of Fluids, Vol.18 (1), 17106, p.16 (2006).

Voutsinas, S.G, (2006), “Vortex methods in aeronautics: How to make things work,” International Journal of Computational Fluid Dynamics 20 (1), pp. 3-18

Papaioannou, T.G., Christofidis, Ch., Mathioulakis, D., and Stefanadis, Cl., “A novel design of a non-cylindric stent with beneficial effects on flow characteristics: an experimental and numerical flow study in an axisymmetric arterial model with sequential mild stenoses”, Journal of Artificial Organs, Vol.31 (8), pp.627-638 (2007).

Prospathopoulos, J., Voutsinas, S.G., (2007),”Determination of equivalent sound speed profiles for ray tracing in near ground sound propagation,” J. Acoust. Soc. Am. 122 (3), 2007, pp 1391-1403.


Voutsinas, S.G, (2007), “Aeroacoustics research in Europe: The CEAS-ASC Report on 2005 highlights,” Journal of Sound and Vibration 299 (3), pp. 419-459.

Baxevanou, C.A., Chaviaropoulos, P.K., Voutsinas, S.G., Vlachos, N.S., (2008), “Evaluation study of a Navier-Stokes CFD aeroelastic model of wind turbine airfoils in classical flutter,” Journal of Wind Engineering and Industrial Aerodynamics 96 (8-9), pp. 1425-1443.

Huberson, S., Rivoalen, E., Voutsinas, S., (2008), “Vortex particle methods in aeroacoustic calculations,” Journal of Computational Physics 227 (21), pp. 9216-9240.

Pantelatos, D., Tzotzolakis, D.C., Mathioulakis, D.S., “Two non circular cross-section bodies at incidence and a high wing-body configuration in a low subsonic free stream”, , Journal of Fluids and Structures, Vol.24 (6), pp.778-798 (2008).

Riziotis, V.A., Voutsinas, S.G. (2008) “Dynamic stall modeling on airfoils based on strong viscous-inviscid interaction coupling,” J. Numerical Methods in Fluids, 2008, 56, pp 185-208.

Riziotis, V.A., Voutsinas, S.G., Politis, E.S., Chaviaropoulos, P.K. (2008) “Assessment of passive instability suppression means on pitch regulated wind turbines,” J Wind Energy, 2008, 11, pp 171-192.

Riziotis, V.A., Voutsinas, S.G., Politis, E.S., Chaviaropoulos, P.K. “Stability analysis of pitch regulated, variable-speed wind turbines in closed loop operation using a linear eigenvalue approach,” J Wind Energy, 2008, 11, pp 517-535.

Stamatopoulos, Ch., Petropoulos, A., Mathioulakis, D.S., Kaltsas, G., “Study of an integrated thermal sensor in different operational modes, under laminar, transitional and turbulent flow regimes”, Experimental Thermal and Fluid Science, Vol.32 (8), pp. 1687-1693 (2008).


Conference Publications H.Snel, G.P. Corten, P.K.Chaviaropoulos, S.G.Voutsinas (2000) “Multiple power levels of wind turbine rotors: The phenomenon and the challenge to CFD” ECCOMAS‟2000, Barcelona.

Papaioannou, Th., Mathioulakis, D., Stamatelopoulos, S., Tsangaris, S., ¨Effect of arterial compliance on blood flow during counterpulsation with intra-aortic balloon pump: Numerical and in-vitro model”, 12th Conference of the European Society of Biomechanics, Dublin, Éreland, pg. 268, 27-30 Aug. 2000.

Nikolaidis, N.M., and Mathioulakis, D.S., “Study of Unsteady flow in a 90 degree bifurcation using P.I.V.”, 12th Conference of the European Society of Biomechanics, Dublin, Éreland, pg. 438., 27-30 Aug. 2000.

Manopoulos, Ch.G., Mathioulakis, D.S., and Tsangaris, S., “Ôheoretical and experimental study of non linear pumping effects in the peripheral vessels, based on the concept of valveless pumps” 4th Euromech Fluid Mechanics Conference, Eindhoven, The Netherlands, 19-23 Nov. 2000.

Papaioannou, T. , Mathioulakis, D., Tsangaris, S., Nanas, J., Stamatelopoulos, S., Moulopoulos, S., “Experimental study of aortic blood flow in counterpulsation with intra aortic balloon pump in a mock circulatory system”, , 1st World Conference on Intraortic Counterpulsation, Athens, 31 Aug-2 Sep, 2000.

Papaioannou, T., Dagre, A., Lekakis, J., Nanas, J., Kanakakis, J., Stamatelopoulos, K., Gialafos, E., Terrovitis, J., Mathioulakis, D., Tsangaris, S., Stamatelopoulos, S., Moulopoulos, S., “The effect of arterial compliance on the hemodynamic effectiveness of intraaortic balloon pumping”, 1st World Conference on Intraortic Counterpulsation, Athens, 31 Aug-2 Sep, 2000.

Manopoulos, Ch.G., Mathioulakis, D., Tsangaris, S., “Theoretical and experimental study of non-linear pumping effects of a balloon pump, based on the concept of valveless pumping”, 2nd European Symposium and Third TEMPERE Workshop on Biomedical Engineering and Medical Physics, 6-8 October 2000, Patras, Greece.

Manopoulos, Ch.G., Pappou, Th., Mathioulakis, D., and Tsangaris, S., “Theoretical models and an experimental study of valveless pumping in the circulatory system”, International Society of Biomechanics, XVIIIth Congress, 8-13 July, 2001, Swiss Federal Institute of Technology.

Pantelatos, D.K., Mathioulakis, D.S., “An experimental study of the flow around an axisymmetric body at high angles of attack”, RTO AVT Symposium on Advanced Flow Management, 7-11 May 2001, Loen, Norway.

Riziotis, V. A., Hizanidi, A., Voutsinas S. G., (2001) “Aeroelastic stability analysis of wind turbine blades using CFD techniques,” Proceedings of the EWEC‟ 01, Copenhagen, Denmark, July 1-7, 2001.

Papaioannou, T., Nanas, J., Lekakis, J., Mathioulakis, D., Kanakakis, J., Tsangaris, S., Stamatelopoulos, S., Moulopoulos, S., “The independent quantitative effect of arterial


compliance, heart rate and blood pressure on acute hemodynamic effectiveness of IABC”, XIVth World Congress of Cardiology, May 5-9, 2002, Sydney, Australia.

Manopoulos, Ch.G., Mathioulakis, D., Tsangaris, S., “Theoretical and experimental study of valveless pumping through impedance induced flow system of tubes formed in a closed loop”, 3rd European Symposium on Biomedical Engineering and Medical Physics, Dept. of Medical Physics, 30 Aug. -1 Sep., 2002, University of Patras, Greece

Papaioannou, Th., Mathioulakis, D., Tsangaris, S., Nanas, J., Stamatelopoulos, S., “In vitro study of flow characteristics during intra-aortic balloon pumping: The effect of heart rate, arterial compliance and pressure”, 12th International Conference on Mechanics in Medicine and Biology, 9-13 Sep., 2002, Lemnos.

Diamandis, A., and Mathioulakis, D.S., “Steady and unsteady flow study in a tube stenosis”, International Conference on Computational and Experimental Engineering & Sciences, 24-29 July 2003, Corfu, Greece.

Pantelatos, D.K., and Mathioulakis, D.S., “Experimental flow study on axisymmetric body released from a UAV cavity, at low Reynolds numbers and high angles of incidence”, 19th Bristol International Conference on Unmanned Air Vehicle systems, 29 Mar-31 Mar, 2004, Bristol, England.

Laskari, A., and Mathioulakis, D.S., “Experimental flow study within deformable elastic tubes of constant and varying thickness”, 7th National Congress on Mechanics, June 24- 26, 2004, Chania, Greece.

Kynigalakis, M., Mathioulakis, D.S., Flow control through pulsating jets”, 7th National Congress on Mechanics, June 24- 26, 2004, Chania, Greece.

Politis, E.S., Chaviaropoulos, P.K., Riziotis, V.A., Voutsinas, (2004) “Aeroelastic stability of wind turbines: the problem the methods and the issue,” Proceedings of the Science of Making Torque from the Wind Conference, Delft, the Netherlands, April 17-21, 2004.

Mourikis, D.G., Riziotis, V.A., Voutsinas, S.G. (2004) “Aerodynamic design using genetic algorithms and application to rotor blades,” Proceedings of the International Conference on Computational and Experimental Engineering and Sciences, Madeira, Portugal, July 26-29, 2004.

Bianchi, E., Russo, A., Fritz, K., Rogelio, F., Dieterich, O., Frosoni, M., Bakker, R., Riziotis, V., Petot, D., Lanz, M. (2004) “Numerical whirl-flutter investigation of the European tiltrotor concept: current status and future prosperts,” 30th European Rotorcraft forum, Marseilles, France, September, 14-16, 2004.

Dieterich, O., Langer, H.J., Sneider, O., Imbert, G., Hounjet, M.H.L., Riziotis, V., Cafarelli, I., Calvo Alonso, R., Clerc, C., Pengel, K. (2005) “HELINOVI: Current vibration Research activities”, 31st European Rotorcraft forum, Florence, Italy, September 13-15, 2005.

Voutsinas, S.G., Visingardi, A., Jianping, Y., Gilles, A., Falchero, D., Dummel, A., Pidd, M., Prospathopoulos, J., (2005), “Aerodynamic Interference in full helicopter configurations and assessment of noise emission: pre-test modeling activities for the Helinovi experimental campaign,” 31st European Rotorcraft forum, Florence, Italy, September 13-15, 2005.


Mathioulakis, D.S., “Droplet deformation in an unsteady flow field: An experimental study”, 1st International Conference on Experiments/Process/System Modelling/Simulation/Optimization - 1st IC-EpsMsO which will be held in Athens, 6 - 9 July, 2005.

Christofidis, Ch., and Mathioulakis, D.S., “Flow study in a flexible circular tube with internal cavities”, 1st International Conference on Experiments/Process/System Modelling/Simulation/Optimization - 1st IC-EpsMsO, Athens, 6 - 9 July, 2005.

Skiadopoulos, A., and Mathioulakis, D.S, “Experimental flow study about a square cross-section fuselage at incidence”, 1st International Conference on Experiments/Process/System Modelling/Simulation/Optimization - 1st IC-EpsMsO, Athens, 6- 9, 2005.

Anagnostopoulos, J.S., and Mathioulakis, D.S., “Numerical simulation and hydrodynamic design optimization of a Tesla-Type valve for micropumps”, 3rd IASME/WSEAS International Conference on Fluid Mechanics and Aerodynamics”, 20-22 August, Corfu, 2005.

Douni, A., and Mathioulakis, D.S., “Pulsating flow around a stationary cylinder: An experimental study”, 3rd IASME/WSEAS International Conference on Fluid Mechanics and Aerodynamics”, 20-22 August, Corfu, 2005.

Nitzsche, F., Feszty, D., Waechter, D., Bianchi, E., Voutsinas, S., Gennaretti, M., Coppotelli, G., Ghiringhelli, G.L., (2005), “The SHARCS project: Smart hybrid active rotor control system for noise and vibration attenuation of helicopter rotor blades,” 31st European Rotorcraft Forum 2005, pp. 52-1-52-15.

Pilou, M., Manopoulos, Ch., Mathioulakis, D.S., and Tsangaris, S., “Experimental study of valveless pumping in a closed loop configuration”, 3rd IASME/WSEAS International Conference on Fluid Mechanics and Aerodynamics”, 20-22 August, Corfu, 2005.

Thepvongs, S., Cesnik, C.E.S., Voutsinas, S.G., (2005), “Aeroelastic and acoustic analysis for active twist rotors,” 31st European Rotorcraft Forum 2005, pp. 124.1-124.10.

Visingardi, A., Decours, J., Khier, W., Voutsinas, S., (2005), “Code-to-code comparisons for the blind-test activity of the tiltaero project,” 31st European Rotorcraft Forum 2005, pp. 73.1-73.18

Perivolaris,Y., Voutsinas, S.G, (2006), “Coupling of RANS and vortex method for prediction of the flow field over wind turbine blades: test case for an “NREL” blade,” EWEC „06, Athens, Greece, February 27 – March 2.

Stamatopoulos, Ch.G., and Mathioulakis, D.S, “An experimental study of the flow temperature and velocity field in a heated stenosis”, 5th World Congress of Biomechanics”, Munich, Germany, July 29th-August 4th, 2006.

Christofidis, Ch.Ch., Papaioannou, T. G., and Mathioulakis, D. S., “The influence of a convergent nozzle on the flow field of a mild stenosis located in a T-junction”, 5th World Congress of Biomechanics”, Munich, Germany, July 29th-August 4th, 2006.

Christofidis, Ch.Ch., Papaioannou, T.G., and Mathioulakis, D.S., “The influence of a convergent nozzle on the flow field of downstream located mild stenoses”, ASME PVP 06 Conference, Vancouver, Canada, 23-27 July, 2006.


Hantziaras V., Mathioulakis D., Kaltsas G., “Flow control using time dependent jets”, 2nd International Conference from Scientific Computing to Computational Engineering, 5-8 July, Athens, Greece, 2006.

Varoutis, S., Mathioulakis, D., Valougeorgis, D., “Nano- and Micro- flows of single gases and binary mixtures through tubes and orthogonal ducts via kinetic theory”, Micro and nanoscale flows, Glasgow, England, 7-8 Dec., 2006.

Riziotis, V.A., Voutsinas, S.G., Politis, E.S., Chaviaropoulos, P.K. (2006) “Investigation of the stability bounds of wind turbines in view of passive instability suppression,” Proceedings of the EWEC „06, Scientific Track, Athens, Greece, February 27 – March 2.

Jianping, Y., Dummel, A., Falchero, D., Pidd, Prospathopoulos J., Visingardi, A., Voutsinas, S.G., (2006), “Analysis of tail rotor noise reduction benefitsusing HELINOVI aeroacoustic main/tail rotor test posttest prediction results,” 32nd European Rotorcraft forum, Maastricht, the Netherlands, September 12-14, 2006.

Pidd, M., Dummel, A., Falchero, D., Prospathopoulos J., Visingardi, A., Voutsinas, S.G., Jianping, Y., (2006), “Validation of aeroacoustic predictions using the Helinovi database,” 32nd European Rotorcraft forum, Maastricht, the Netherlands, September 12-14, 2006.

Riziotis, V. A., Voutsinas S. G., (2006) “Modelling of wind tunnel interference on helicopter measurements and assessment of the currently used corrections based on the HeliNovi database,” 32nd European Rotorcraft forum, Maastricht, the Netherlands, September 12-14, 2006.

Thepvongs, S., Cesnik, C.E.S., Voutsinas, S.G., (2006), “Numerical investigation of integral twist actuation for BVI noise reduction,” Annual Forum Proceedings - AHS International II, pp. 919-934

Visingardi, A., Dummel, A., Falchero, D., Pidd, M., Prospathopoulos, J., Voutsinas, S.G., Jianping, Y., (2006), “Aerodynamic Interference in full helicopter configurations: validation using the Helinovi database,” 32nd European Rotorcraft forum, Maastricht, the Netherlands, September 12-14, 2006.

Riziotis, V.A., Voutsinas, S.G., (2006) “Advanced aeroelastic modelling of complete wind turbine configurations in view of assessing stability characteristics,” Proceedings of the EWEC „06, Scientific Track, Athens, Greece, February 27 – March 2.

Markou, H., Hansen, M.H., Buhl, T., van Engelen, T., Politis, E.S., Riziotis, V., Poulsen, N.K., Larsen, A.J., Mogensen, T.S., Holierhoek, J.G., (2007), “Aeroelastic stability and control of large wind turbines – main results,” Proceedings of EWEC‟ 07, Milan, Italy, May 7-10, 2007

Riziotis, V.A., Voutsinas, S.G., Politis, E.S., Chaviaropoulos, P.K. “Stability analysis of pitch regulated, variable-speed wind turbines in closed loop operation using a linear eigenvalue approach,” the Science of Making Torque from the Wind Conference, Journal of Physics, Conference Series 75 (2007) 012068

Barthelmie, R.J., Rathmann, O., Fradsen, S.T., Hansen, K., Politis, E., Prospathopoulos, J, Rados, K., Cabezon, D., Schlez,.W., Philips, J., Neubert, A., Schepers, J.G.,van der Pijl, S.P., (2007), “Modeling and measurements of wakes in large wind farms,” the Science of Making Torque from the Wind Conference, Journal of Physics, Conference Series 75 (2007) 012049


Stamatopoulos, Ch., and Mathioulakis, D.S, “Temperature and velocity measurements within blood vessel models of pathophysiological characteristics”, 7th International Symposium on Particle Image Velocimetry, Rome, Italy, 11-14 Sep., 2007.

Stamatopoulos, Ch., Papaharilaou, Y., Georgakarakos, E., Mathioulakis, D.S., Katsamouris, A.N., “Experimental study of the flow regime in a realistic model of abdominal aortic aneurysm”, Proceedings, 3rd Conference of the Hellenic Society of Biomechanics, Athens, p.149-150, September 2008.

Barthelmie, R.J., Fradsen, S.T., Rathmann, O., Politis, E., Prospathopoulos, J, Rados, K., Cabezon, D., Schlez,.W., Hansen, K., van der Pijl, S.P., Schepers, J.G., (2008), “Flow and wakes in large wind farms in complex terrain and offshore,” Proceedings of the EWEC „08, Scientific Track, Brussels, Belgium, March 31 – April 3.

Riziotis, V.A., Voutsinas, S.G., (2008) “Aero-elastic modelling of the active flap concept for load control,” Proceedings of the EWEC „08, Scientific Track, Brussels, Belgium, March 31 – April 3.

Riziotis, V.A., Voutsinas, S.G., Politis, E.S., Chaviaropoulos, P.K. (2008) “Identification of structural non-linearities due to large deflections on a 5MW wind turbine blade,” Proceedings of the EWEC „08, Scientific Track, Brussels, Belgium, March 31 – April 3.

Kounadis, D., and Mathioulakis, D.S, “Flow velocity measurements inside a self-oscillating collapsible tube”, 3rd IC-EpsMsO conference, Athens, July, 2009.

Asproulias, J., Lekas, Th., and Mathioulakis, D.S., “Aerodynamic loading of a box-type biplane configuration”, 3rd IC-EpsMsO conference, Athens, July, 2009.

Mouzakitis, A., Touliatos, Ch., Mathioulakis, D.S, “A vowel production study, using sylindrical tubes: a static and dynamic case”, 3rd IC-EpsMsO conference, Athens, July, 2009.

Politis, E.S., Chaviaropoulos, P.K., Riziotis, V.A., Voutsinas, S.G. (2009) “Stability analysis of parked wind turbine blades,” Proceedings of the EWEC „09, Scientific Track, Marseille, France, March 16-19.

Politis, E.S., Rados, K., Prospathopoulos, J., Chaviaropoulos, P.K., Zervos, A., (2009), “CFD modeling issues of wind turbne wakes under stable atmospheric conditions,” EWEC „09, Marseille, France, March 16-19.

Laboratory of Aerodynamics - NTUA · Laboratory of Aerodynamics Research Activities Theoretical External Aerodynamics and Aeroelastic Analysis Aerodynamic and Aeroelastic analysis

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