FLOWlab

FLOWlab educational PIV system

• Circulating channel / aquarium (approx. 1200 mm x 150 mm x 300 mm) with thruster (200 W) and flow bodies (cylinder, wing sections, custom objects can easily be integrated by 3D printing)
• Measuring section approx. 140 x 125 x 200 mm, similar to the historical Prandtl water channel
• Low-energy light sheet with pulsed laser class 2M (500 mW, divergent, 0.5 mm thick, pulsed, frame-straddling, wavelength 638 nm)
• Camera with 2.35 megapixel and frame rate of 160 fps (USB 3.0)
• Sensor diagonal 7.9 mm; 3.45 µm pixels
• With bandpass filter 638 nm
• Lens F1.4 f 16 mm, 2/3" sensor, low distortion
• Developed for PIVlab, the free MATLAB toolbox (Image Processing Toolbox and Image Acquisition Toolbox required)
• Laser and camera can also be used for other experiments in water up to 1 m/s and 300 mm x 200 mm FOV
• incl. seeding particles (50 µm polyamide)

Example data from the FLOWlab can be downloaded from Google Drive.

At (German) schools, according to the guideline of the Conference of Ministers of Education and Cultural Affairs (Kultusministerkonferenz), the operation of our laser is possible without any effort, even without a laser safety officer and in compliance with very simple protective measures:

Our PIV training system uses a pulsed, synchronized laser of laser class 2M. The use of a laser enables very thin, defined light cuts and is ideally suited for PIV. By using bandpass filters in the camera, the experimental lab does not need to be darkened. The use of a synchronizer and pulse laser extends the range of application considerably.

The following conditions apply to the use of our laser in schools:

• Keep laser under lock and key
• Inform students about laser safety
• Use only under supervision
• Put up a warning sign
• Do not look into the laser

"Guideline for Safety in the Classroom" of the Conference of Ministers of Education and Cultural Affairs (Kultusministerkonferenz, source)

Handling lasers

• The provisions of the accident prevention regulation on laser radiation (DGUV regulation 12) apply to lasers. The school-relevant provisions of this UVV are detailed below.
• Only lasers of classes 1, 1M, 2 and 2M according to DIN EN 60 8257 or 3A according to DIN EN 60 825-1 up to the March 1997 edition may be used in schools. For the definition of the laser classes, see III - 5.
• Lasers of classes 1M, 2, 2M and 3A may only be stored under lock and key. Prior to setting up and performing experiments with Class 1M, 2, 2M, and 3A lasers, the students involved and the observing students shall be instructed on the eye hazard of the laser light. These lasers may only be operated under the supervision of the teacher.
• The experimental area where Class 1M, 2, 2M, and 3A lasers are being experimented on shall be marked with a laser warning sign during operation. The laser area of experimental setups is to be secured against unintentional entry by means of demarcation. Set-up and performance of experiments with Class 1M, 29, 2M and 3A lasers must be designed in such a way that looking into the direct laser beam or into the reflected beam is avoided, e.g. by shielding.
• When using Class 1M, 2M and 3A lasers, the beam cross-section must not be reduced, i.e. they must not be used with optically collecting components (e.g. magnifying glasses, collecting lenses).

Laser class 2M

Class 2M lasers emit an accessible laser beam in the visible wavelength range (400-700nm) that is either divergent or expanded. A radiation power of up to 0.5W (= limit for class 3B) is permissible for the entire beam.