35th AIAA Applied Aerodynamics Conference, June 509, 2017, Denver, Colorado, USA
In 2013, Defence Research and Development Canada, in collaboration with the United States Air Force Research Laboratory and the Australian Defence Science Technical Group, embarked on an ambitious development and evaluation program to assess the performance benefits of Vortex Contol (VC) FinletsTM installed on the C-17 Globemaster III aircraft. This paper will discuss three wind tunnel tests and significant complementary computational fluid dynamics analyses that occurred over the course of a year and across international borders. Since the primary role of the Finlets is to reduce drag and hence reduce fuel consumption, or increase range and endurance, the primary objective of this work was to achieve the greatest drag decrement by understanding the flow around the C-17’s tail and the mechanism(s) by which the devices control that flow. The secondary objectives were to
determine the effect of the devices on air-drop and stability and control, albeit the latter assessment was limited. The wind tunnel tests demonstrated a maximum reduction in drag of 1.8% with no significant side-effects. Since the devices provide small decrements in drag by changing the complex flow around the empennage, several challenges in testing and simulation were encountered and were generally addressed with inexpensive solutions. To that end, classic and advanced techniques were used during testing with positive success.
American Institute of Aeronautics and Astronautics