Thermal flow field imaging in air using T-sensitive PIV particles

Thermographic PIV

Thermographic PIV marks a real breakthrough for simultaneous flow velocity and temperature measurements, because it works with phosphorescent PIV particles, which are suitable both for PIV and laser induced thermometry measurements with only slightly modified PIV systems.
The phosphorescent PIV seeding material comes as a ceramic powder consisting of 2 µm particles showing a temperature sensitive emission after UV laser excitation which is used both for PIV and thermometry.
Due to their small size the powder particle rapidly assume the velocity and temperature of the surrounding flow.
Time-resolved thermal flow field imaging is possible based on High-Speed FlowMaster PIV systems.

FlowMaster Thermographic PIV
System Features
  • Simultaneous flow velocity and temperature imaging using slightly modified FlowMaster PIV systems with phosphorescent flow tracer
  • Laser induced temperature imaging possible up to 900 K
  • Time-resolved Thermographic PIV can be applied at kHz frame rates
Gas temperature measurements in the hot air temperature calibration jet using different measurement techniques

Measurement Principle

Thermographic PIV is a combination of two independent commonly used measurement techniques:

Flow field velocities are determined from double frame images of the seeding particles using particle image velocimetry (PIV). All 2D PIV techniques can be applied, such as planar, stereo and time resolved PIV.

Flow temperature is measured using phosphor thermometry. A 2-color ratiometric approach is used to exploit the temperature dependent behavior of the phosphorescence.
Natural convection over a hot plate

Thermographic PIV Systems

Several hardware configurations are possible for Thermographic PIV. Existing hardware such as a FlowMaster PIV system can be easily upgraded to perform simultaneous flow field and temperature imaging.

Accessories such as seeding devices and a hot air temperature calibration jet are available.