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Wind tunnel

The Italian wind tunnel

Newton wind tunnel

proud of our project
The Newton laboratory has an installation of a 280 kWatt subsonic wind tunnel. The air is designed to flow in a closed return wind tunnel, Goettingen type.
The test facility has been built to run with either an open or closed test section, as needed for particular experimental program. The required electric energy required is produced by mean of a power generator fully integrated with the wind tunnel.

 

Technical specifications

General, Test Section, Test Chambers, Fans, Instrumentation, Control and Data Acquisition Station
The project

The project

Installation

Installation

Testing

Testing

Test sections

The wind tunnel has been designed to allow easy replacement of the converging and diverging elements, currently providing three possible 5m long test sections.

Test section

Maximum speed

Contraction ratio (nozzle)

Length to hydraulic diameter ratio

1,25m x 1,25m - A=1,6mq

240 kmh

10,2

4

1,5m x 1,5m - A=2,3mq

190 kmh

7,1

3,3

1,9m x 1,9m - A=3,6mq

125 kmh

4,4

2,6

Test section A

Test section A

Test section B

Test section B

Test section C

Test section C

Sample dimensions

Experiments to obtain aerodynamic parameters that affect automobile performance, engine cooling, brake cooling and wind noise are made with either at full scale or with scale models.
A key issue for automobile testing is the blockage based on frontal area= the ratio of the model frontal area to the test section area.
The flow around automobiles is often more characteristic of “bluff bodies” than of “streamlined bodies”: this means that there is always a sizable region of separated flow. The wind tunnel test section needs to be sufficient long so that these separated flow regions “close” before encountering the end of the test section and the entry of the diffuser.
In such case it is really helpful to use Newton Wind Tunnel in the open test session configuration.
For experiments with large objects in which the model is held stationary during data gathering and the maximum speed is below 0,3 Mach (350 kmh) it is possible to apply the similarity approach in order to work on a scaled model.
By keeping the same Reynolds number the model and the full scale flows will be dynamically similar: the non dimensional functions for fluid velocity components, pressure coefficients, density, viscosity, the force and the moments will be the same.
Actual dimensions

Actual dimensions

Size to scale

Size to scale

Dynamically similar

Dynamically similar

Test models

It is possible to realize test models starting from the 3D CAD drawing to the final CNC sample.
CAD production

CAD production

3D extrusion models

3D extrusion models

Numerical control models

Numerical control models

Measurements on the model

Force and moments, Pressure mapping, Surface flow visualization
Force and moments

Force and moments

At present time the force and moments to calculate the aerodynamic forces are acquired by mean of n. 3 load cells and n. 3 torque meters.
For the actual tests regarding the aerodynamic characteristic of helmets this system has been embedded inside a standard headform.

Pressure mapping

Pressure mapping

The model can be special prepared in order to accommodate small tubes (2mm diameter) to acquire the local pressures. At present time up to 18 pressure locations can be acquired.

Surface flow visualization

Surface flow visualization

Information about the flow on the surface of the model being studied helps to investigate stagnation point locations, separation lines, location of boundary layer transition. In Newton lab we commonly use a smoke generator or, alternatively tufts. The tufts being light and flexible will align themselves with the local surface flow as a result of direct aerodynamic forces.

Termodynamics

We have realized a new test headform all covered with thermocouple. This headform will be used to measure the effect of the ventilation of the helmet.
The software, developed by Newton, shows the 3D model of the head and it represents with colored contour style the various temperatures of the head. At the beginning the head is red and then, thanks of the air inlet/outlet some areas with different colors appear in relation to colder areas.
We can apply up to 32 thermocouples on a real athlete/tester that is practicing in front of the wind tunnel. We can monitor the temperature to check the ventilation and thermal behavior of the clothing.
Testing head with temperature sensors

Testing head with temperature sensors

Sensors applicable on athletes' bodies

Sensors applicable on athletes' bodies

Software entirely developed by Newton

Software entirely developed by Newton

Acoustics

La testa di prova utilizzata per le prove di aerodinamica monta due microfoni in corrispondenza al meato uditivo. La strumentazione consente di analizzare il rumore indotto dal flusso d'aria sulla superficie del casco e dalla eventuale turbolenza indotta. La misurazione si articola attraverso la determinazione del livello sonoro (dBA), l'analisi d'ottava e in frequenza.
Testing head with microphones

Testing head with microphones

Induced noise analysis

Induced noise analysis

Instrumentation

Instrumentation

Turbulence level

Variations in flow quality between different wind tunnels will cause variations between the results obtained when experiments for the same Reynolds number are performed. One of these flow quality parameters is turbulence level. Turbulence spheres were used to obtain drag coefficient measurements for a range of Reynolds number flows.
The critical Reynolds number for freestream atmospheric transition was taken to be 385,000 and was divided by the measured critical Reynolds number to obtain a turbulence factor.
This comparison with the 5,5 inch turbulence sphere yielded the turbulence factor TF=1,02: the result indicates that the Newton wind tunnel has an excellent quality of flow with freestream turbulence levels below 0,2%.
Turbulence spheres

Turbulence spheres

Software and control

The control of the wind tunnel is completely separated from the data acquisition activities. Two separated computer systems are used: the first control the speed of the wind and all the safety procedures, the second is dedicated to data acquisition (up to 32 channels) and post processing.
The software can be personalized on the base of special requests.
Software

Software

Controls

Controls

Customisations

Customisations

Movies

Jet Helmet Ventilation Test in the Wind Tunnel

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Armani sportswear test with Newton Wind Tunnel

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Newtonlab wind tunnel - SPARCO eXtrema suit

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Newton Wind Tunnel Testing Rui Costa Lampre Merida

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Team Lampre Merida during Newton Wind Tunnel test

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Newton Wind Tunnel Testing Merida

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Pininfarina Helmet in the Newton WindTunnel

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FIA AND SFI CERTIFICATIONS, MOTORBIKE HELMETS, PERSONAL PROTECTIVE EQUIPMENT, TYPE APPROVAL OF TWO- AND THREE-WHEEL MOTOR VEHICLES.