Microscale flow visualization and its density measurement with the aid of a laser-induced-fluorescence technique

A laser-induced-fluorescence (LIF) technique is applied to the flow visualization of microscale supersonic free jets, chosen as typical microscale heat and fluid flows encountered often in high technology, and also to the quantitative measurement of density from the detected LIF intensity. The entire flowfield visualization of the microscale jets seeded with iodine molecules radiating fluorescence induced by an argon ion laser is realized well enough to recognize in detail the three-dimensional fine flow structure. Simple theoretical relationships based on quantum electronics are derived to estimate the quantitative density from the detected LIF intensity induced by multi- and single-mode laser light, and the agreement between the theoretical relationship and experimental results is fairly good