Past experiences/research

1. Vertical Lift Research Center of Excellence Department of Aerospace Engineering Penn State PAX Streamline Tushar Prabhakar

9. Schematic Representation of a CF actuated Variable Span Rotor Fixed inner section of blade Sliding outer section Restraining Spring High Ω Low CF Force Little extension High CF Force Large extension Retracted or short configuration Extended or long configuration Low Ω L - Position of center of mass of sliding section + end cap u - Deformation

13. Variable Span Rotor , Designed and Fabricated (disassembled)

14. Variable Span Rotor , Designed and Fabricated (assembled) Inner fixed section of blade (11” span) Guide-rail groove / Safety slot End Cap Outer sliding (telescoping) section of blade (11” span) Connection to Hub Screw connecting end cap to outer sliding section of blade 3”

20. Sony Video Digital Camera Infra-red Triggered Strobe Light 5 HP Motor Infra Red / Trigger Mechanism

21. VSR Video

22. Inner fixed section of blade Guide rail groove / Safety slot Outer sliding section of blade starting position .35” Extension 3.7” Extension Outer sliding (telescoping) section of blade Test Video Single Frame at 100 RPM Test Video Single Frame at 240 RPM

25. Simulations with non-linear softening springs Extension (in) Force (lbs) Rotational Speed (RPM) Extension (in)

26. The use of non-linear piecewise-continuous springs Extremely stiff to a critical force, then displays soft linear behavior Virtually no extension up to a certain RPM, followed by a large extension over a very small increase in RPM

28. Analytical simulations for short/long span configurations (modeled on the BO-105) Rotor WITHOUT a locking mechanism For CF actuated span change, shorter span corresponds to lower Ω and vice-versa Can the short-span, low- Ω rotor (with high collective pitch) generate required thrust? If span is increased along with increase in Ω and simultaneous reduction in collective, does that yield power reductions?

29. Mission Analysis/Con-OPS, without locking mechanism Collective (deg) Thrust (lbs) Shorter span with decrease in rotational speed, higher collective provides enough lift for the BO-105 Larger span with increase in rotational speed, increased payload capability within the power requirements BO-105 Rotor Thrust (lbs) Rotor Power (HP)

30. Analytical simulations for short/long span configurations (modeled on the BO-105) Rotor WITH a locking mechanism Previous Figure showed that a large span rotor with a simultaneously large RPM did not yield power reductions because of a much higher tip mach number relative to the baseline. If the radius was decreased, with increase in Ω such that the tip mach number is the same as the baseline/nominal configuration, how much collective would be needed to provide lift? What if the RPM was increased to achieve the span increase, but then locked in place, and the RPM then reduced to produce the same tip mach number as the baseline/nominal configuration

31. Mission Analysis/Con-OPS, with locking mechanism Shorter span, increased Ω M = .58 in all cases, marginal increase in collective Collective (deg) Rotor Thrust (lbs) Larger span, decreased Ω M = .58 in all cases, leading to reduction in power reqd. + increase in payload capability Rotor Thrust (lbs) Rotor Power (HP)

34. Circulation Control Wing Concept The Idea behind this was to actively reduce drag on cars/suvs. Studies by Georgia Tech (Dr. Robert Englar), have shown that this concept can reduce drag on Semis. Using the Coanda Effect, is it possible to manipulate the actual shape of cars at different speeds? Active Reduction of Drag (Using Coanda Effect)

36. Wind Tunnel CAD, I/2 of the model. (Back of the tunnel identified as a Symmetrical Side) CFD Analysis of a SUV (Modeled on the Suburban at 67 MPH (30.05m/s). Circulation Control Aerodynamic Device Inlet – 30.5 m/s

40. Questions ? WE ARE ......………………………………………………………………………………… PENN STATE