Flow Visualization Laboratory
The Flow Visualization Laboratory aims the investigation of fluid flows by means of flow visualization techniques. The lab is equipped with cutting-edge equipment covering the following experimental techniques:
» High-speed shadowgraph
» Laser Doppler Anenometry
» Particle Image Velocimetry
» Ultrasonic Velocity Profiler
Principal Investigator
Prof. Rigoberto Eleazar Melgarejo Morales, Dr.
Call: +55 (41) 3279-6599
Fluid Mechanics
The lab focuses primarily in multiphase flows applied in offshore oil extraction sites, both in topside and subsea endeavors. Some of the current research projects are briefly described below:
Bubble flow in confined geometries
Dynamics of compound drops and bubble-drop interactions
Stability of foams and emulsions
Wake structure and dynamics
Slurry Flow
Capability
The Laser Doppler Anemometry (LDA) can be used to provide real-time, non-intrusive measurements of individual particle velocity and turbulence measurement in transparent fluid flows. Our lab is equipped with a LDV-200TRX velocimeter (Artium Technologies, USA). Two coherent laser beams are crossed to form a small measurement probe volume. The light scattered by a fluid particle is detected to calculate the vertical and horizontal velocity components by means of the Doppler effect
LDV – 200TRX
Velocity measurement range: -400 to 1200 m/s
Velocity accuracy: 0.1%
Laser type: Diode pumped solid state (DPSS)
Wavelength: 100 – 2000 mm
The high-speed shadowgraph technique is widely used in multiphase flows to measure the shadow of the dispersed fluid phase. Our lab offers a wide variety of high-speed cameras and lenses devoted to this matter. Most of our studies are focused on bubble flow in water chambers.
A Particle Image Velocimeter (PIV) is used in our lab to measure liquid velocity in a plane. The flow is seeded with light-scattering particles that are illuminated by a laser sheet (Evergreen HP). The liquid velocity is obtained by measuring the average displacement of the particles in a period of time. Our lab is equipped with a cutting-edge 2D – Stereo PIV system (LaVision, Germany) and uses the DaVis FlowMaster software for image processing
sCMOS
Number of pixels: 2560 – 2160
Frame rate: 50 fps
Exposure time: 15 μs – 100 ms
Photron SA4
Number of pixels: 1024 – 1024
Frame rate: 3600
Laser Evergreen HP
Laser type: Dualcavity Nd :YAG
Wavelength: 3600
Energy per pulse: 400 mJ
Frequency: 15 Hz
The Ultrasonic Velocity Profiler (UVP) is a measurement technique based on ultrasound Doppler, to acquire velocity profiles of liquid flows. The technology is the same as medical or oceanographic doppler devices. Ultrasonic pulses are emitted and are reflected by flowing particles, solid or gas. Comparing both emitted and received acoustic signals, shifted in frequency due to the Doppler effect, the velocity can be evaluated at various distances on the transducer measuring axis. The technique can be used in combination with distance measurement to detect interfaces.
The technique can be used in combination with distance measurement to detect interfaces.
Spatial resolution: up to 0.2 mm
Temporal resolution: up to 200 fps
Velocity: up to 3 m/s
Up to 32 channels
50Msamples/sec
12 bit ADC
Pulser Receiver
100-400V pulser voltage
0.5 – 10 MHz transducer frequency
Analog Gain up to 30dB
Transducers
1, 2.25, 4, 5, 8 and 10 MHz