Using molecules to measure rate of flow

Its main advantage is that no measuring instruments or small particles, such as glass beads, need to be inserted into the flow. These techniques fail if, for example, the particle density is too low or the measurement techniques influence the flow.

Bominaar's research was part of a project funded by Technology Foundation STW.

Jeroen Bominaar set out to improve the new measurement technique, apply it and study its effect. The method involves directing a focused laser beam in a single line in an airflow, which results in some of the nitrogen and oxygen molecules in the line being converted into nitric oxide molecules.

Shortly afterwards the line of new molecules is irradiated with a second laser and this causes the molecules to fluoresce. As these molecules move with the airflow, the speed of the airflow can be accurately measured.

The technique can be used in situations where current particle techniques fall short of the mark, for sample, in accurate speed measurements in wind tunnels, on satellite engines or in the wake of moving objects.