Revolutionary Performance For Ultra Low Reynolds Number Vehicles, Phase II

A novel technique for controlling transition from laminar to turbulent flow in very low Reynolds number conditions has been developed. Normally flows with Reynolds numbers in the range of 20,000 to 120,000 are dominated by laminar separation bubbles and are difficult to transition without using very large traditional trip devices, such as distributed roughness. Additionally, these traditional trips are sized for one flow condition and are either not effective at off-design conditions or create a large device drag penalty. RHRC's innovative transition control technology is capable of transitioning flow across a wide range of low Reynolds number conditions without resizing or incurring an off-design performance penalty. The system also produces minimal device drag. The novel transition control technology was shown to reduce trip drag penalties by as much as 35% to 60% when compared to correctly sized traditional trips, and increasing to as much as 190% at off-design conditions. In addition, the system can be implemented without external power. The commercialization potential for the technology is extremely promising, with applications such as micro unmanned air vehicles, high-altitude long-endurance aircraft, Mars exploratory flyers, and propeller systems. More »