LIF imaging monitors in-situ the process of fluid mixing on micro and macro scales with high spatio-temporal resolution. 1-color LIF imaging as well as 2-color LIF ratio imaging are applied in LaVision’s FluidMaster systems for scalar flow imaging.
Reactive mixing of liquid flows
In case of reactive mixing of two different pH-solutions a pH-sensitive LIF tracer is used allowing 2-color LIF imaging for quantitative pH measurements. For scalar flow imaging this ratiometric 2-color LIF method is best practice, because its LIF signal ratio is independent of local laser energy and tracer concentration variations as well as laser beam absorption effects. On the other side 2-color LIF imaging requires two detection channels realized with two cameras or one camera in combination with an image doubler.
Related applications: LIF for gas entrainment in aqueous flows
Mixing of a turbulent gas jet
In case the mixing process is well presented by the mixture fraction, the LIF signal of one seeded flow component is already proportional to the volume (=mixture) fraction. This simple 1-color LIF strategy needs corrections for local laser energy fluctuations and laser beam absorption effects. LaVision’s FluidMaster systems support such corrections for quantitative flow imaging.
Related applications:
O2 monitoring in mixing gas flows
Laser imaging of gas flow mixing w/o flow seeding:
FluidMaster laser imaging system based on Rayleigh scattering