Chycago

Flow Environment

The CHyCAgO facility allows experimental studies of stirring tank flows. The facility has been designed in the frame of the LEDITH joint laboratory with CETIM (www.ledith.eu ).

The facility is described as a cylindrical tank with flat bottom, three baffles with an adaptive distance between the baffles and the wall, and a central shaft allowing mixing through two types of impeller: 4-blades paddle (90°) and 4-blades pitched paddle (45°) with the distance between the impeller and the bottom wall which can be adapted.

The facility can produce agitated flows with a rotating speed range from 3 to 600 rpm with a flow producing a torque up to 120Nm. The facility is fully transparent to allow optical access and use of optical measurement techniques like stereo-PIV.

Instrumentation Techniques

Instrumentation is installed on the engine and on the shaft. Optical devices are also used. Instrumentation techniques include

• engine encoder to regulate the rotor speed
• gear reduction to measure the actual speed on the shaft
• strain gauge based torque-meter
• vertical and horizontal calibration plates for imaging techniques provided with a 4 mm optical displacement sensor
  - Double pulsed lased and synchronized cameras for Stereoscopic Particle Image Velocimetry measurements

Fields of Application

Given the large size, the facility is ideal for the study of industrial-scale mixing phenomena and for validation of CFD codes. The versatility of the facility includes the possibility to study multiphase flows, including solid and gaseous dispersion. The high engine power makes the facility suitable for study of fluids of high viscosity while achieving turbulence at the same time.  

Stereo-PIV in water at different rotation speeds and with the two different types of impellers were measured in the facility and led to two conference papers.

Recently, stereo-PIV and PTV measurements were performed with water and up to 10% in volume of hydrogel particles, allowing the calculation of both solid and liquid velocities. Results will be published in the near future.

Project Highlights

 D. Laboureur, C. Spaccapaniccia, M. Van Cappellen, C. ALzard, T. Aiouaz, J.M. Buchlin, « Mesures de stéréo-PIV dans une cuve agitée », CFTL 2018, 17-21 September 2018, Dourdan, France, Proceedings p.271-278

C. Spaccapaniccia , C. Alzard,  D. Laboureur, T. Aiouaz, M. Van Cappellen, F.Bérot and J.M. Buchlin, “Experimental and numerical study of solid – liquid mixing in stirring tank ”, MIXING16, 9-12 September, Toulouse, France

Print

Two-Phase Flow Facilities

Print

Wind Gallery WG-1

The Wind Gallery is a facility that was designed for the study of pollutant gas cloud mitigation by water spray curtain. It reproduces a correctly scaled pollutant leak that is absorbed and dispersed by a liquid curtain, which can be oriented either upward or downward. The test section is 1m high, 1.3 m wide and 7 m long. A battery of four ejectors mounted at the back end drive the airflow.

The test section is also equipped with a wave tank of 1m wide, 4m long and 0.2 m deep, with the water waves generated by a plunger, to allow for wind-wave effects on wind energy harvesting for aligned and fully-opposed wind-wave configurations at a scale of about 1:300.

The ejectors maintain a low pressure inside of the test section to ensure that gas leaks migrate toward the interior of the facility.  The flow speed in the Wind Gallery can be varied from 0.25 to 1 m/s, which is equivalent to full-scale wind speeds ranging from 5 to ~18 km/h.  Curtains of 0.5 m height are installed, representing 5 m high curtains at full scale.

The Wind Gallery was constructed in compliance with material resistance requirements for the use of special chemicals.  Releases of SF6 , N2 and CO2 are used to simulate the pollutant. Wind speed, pollutant source and water curtain characteristics are controlled and measured during the tests.  In addition, pollutant concentration and temperature profiles can also be quantified. Safety devices and measures are installed at the facility to protect test personnel.

Print

Water Spray Facility WS-1

The Water-Spray facility is designed for testing industrial nozzles and for the general study of liquid sprays that are generated by pneumatic and pressure nozzles. It is equipped with a pump capable of delivering spray flow rates up to 1 dm³/s at a pressure of 8 bar, with metering of both flow rate and feed pressure, into a 3 m by 4 m collecting pool.  Either a single nozzle or an array of nozzles can be tested.

The facility allows real-time measurement of velocity and droplet size in sprays of up to 2 m in height by means of a phase Doppler anemometer and determination of the liquid mass flux mapping by means of calibrated tubes.  The facility is also equipped with a set of gas burners and vertical flat plates, which are instrumented with thermocouples and radiometers, to simulate thermal shielding by a water curtain.

Print