Measuring airflow is nothing new. It has been done for decades using a variety of techniques. On one hand are the very simple but still effective techniques, like tufts or smoke, which give users a sense of what the flow does but not much more than that. On the other hand, you have high-complexity, high-cost techniques, like particle image velocimetry (PIV) or the scanning approaches where probes are deployed on a traversing system. A numerical approach, where you simulate flows with your computer, always leaves one wondering if the result is close enough to reality. Especially challenging are low-speed applications, like HVAC room ventilation or passenger comfort in cars and trains, where most traditional methods are not applicable and the boundary conditions for a simulation are difficult to determine.
Streamwise gmbh of Männedorf, Switzerland, has developed a novel approach for intuitive and fast capturing flows, even in low-speed applications below 1 m/s.