CPACT Webinar on
Particle Image Velocimetry and Shadowgraphy:
Advanced Optical Techniques for Spray
Characterization
Georgios Pyrgiotakis, Bristol Myers Squibb
21st October 2025 at 2pm (EDT), 7pm
(UK time)
Particle Image Velocimetry (PIV)
and Shadowgraphy are advanced optical measurement techniques employed to
visualize and quantify fluid flow velocities and particle sizes. PIV involves
illuminating the sample area, capturing images at rapid intervals, and
analyzing particle displacement to compute velocity fields. This technique is
crucial for understanding complex spray and fluid dynamics, particularly in
nozzle-based fluid systems. Shadowgraphy visualizes changes in the refractive
index of transparent media, such as sprays or jets, by using a backlight to
illuminate droplets. This allows cameras to capture high-contrast images synchronized
with a laser source, making shadowgraphy a complementary tool to PIV for
particle sizing and movement analysis. The PIV does not belong to the class of
instruments, as it is a custom system that is built around the specific
application.
This study presents the
application of PIV and shadowgraphy techniques for spray characterization
during spray drying process to understand the relations between the operation
parameters of a spray (pressure, liquid flow, gas flow), to the droplet size
that is a critical factor for the particle size. Comparative analysis showed
consistent trends in particle size measurements, though absolute values varied,
highlighting the importance of standardized image processing. The study
systematically varied gas and liquid flow rates, nozzle types, and material
properties to assess their impact on particle size and velocity. Larger
particle sizes were observed with increased liquid flow and decreased gas flow
rates. Velocity measurements increased with higher fluid flow rates, and larger
particles tended to move faster in the flow direction.
This webinar will last no longer than one hour.
Please register direct at https://universityofstrathclyde.webex.com/weblink/register/r4fb2cf4bcc5023902f5014d0a5bc62be
