SBIR-STTR Award

The proposed effort will result in the development and wind tunnel validation of a universal pitch cycloidal propeller system which can provide efficient vertical takeoff or landing (VTOL) UAV propulsion. This form of propulsion is currently in use in marine applications, and has been studied by major aircraft manufacturers and the military. Study and wind tunnel test results support the concept; however, until the advent of the micro-computer and associated motion control technologies, efficient cycloidal propellers were only feasible for relatively narrow speed ranges. This effort will capitalize on computer control to provide a universal pitch cycloidal propeller that will allow efficient flight across a wide range of flight speeds and conditions. Cycloidal propulsion provides a unique 360-degree directional flight capability through use of a low-velocity, high-volume flow technique of exceptional efficiency. The cycloidal propeller, which provides both thrust and lift, can make near instantaneous change in thrust direction without re-orientation of the propellers plane of rotation. Major advantages of this system include efficient hovering flight, low-noise signature, near-instantaneous change in thrust direction, wide speed range, safety, and packaging. BOSCH Aerospace, Inc., has teamed with the Raspet Flight Research Center of Mississippi State University to conduct Phase 1. The research will encompass systems engineering, mechanical design, computer modeling, control algorithm development, fabrication, and wind tunnel tests. A fully functional propeller and control system will be completed and tested during Phase 1. Documentation from this effort will include study, design, and tests results.

Benefits:
The adaptation of the cycloidal propeller to UAVs is an important development and its benefits include expanded UAV application in all sectors. Cycloidal propulsion is also important to the future of lighter-than-air (LTA) flight because it provides positive control at zero airspeed, a major deficiency in LTA today. Achieving helicopter-like control of UAVs would potentially allow for high-altitude flights where this improved propeller efficiency and application approach are critical. Probable applications of a quiet, easy to fly UAV in the commercial sector would include advertising, police surveillance, disaster monitoring, and scientific data collection. The adaptation of the cycloidal propeller would expand UAV applications in all sectors, and provide enhanced safety and noise reduction.

Keywords:
Cycloidal Propeller Curtate Prolate Cyclogiro Trochoidal Motion Propulsion Cycloidal Efficient

The proposed effort will result in the development, testing, and demonstration of a full- scale, flight weight, three-axis cycloidal-propeller system. Additionally, two studies will be accomplished: 1) A Design Study of a universal-pitch control mechanism, a design desirable for flight speeds between about 130 and 400 knots; and 2) A Transition Study to define movement from R&D to an operational system. The basis for the Phase II proposal emerged from Phase 1 research where the curtate cycloidal propeller was demonstrated, and achieved significant levels of thrust. BOSCH Aerospace, Inc., and our subcontractor, Mississippi State University RASPET Flight Research Laboratory will expand the development to demonstrate three-axis control on a test fixture. Our team is experienced, well-qualified, and well equipped with appropriate computers and computational skills, as well as fabrication and test facilities. Management of this project will be in three distinct segments: 1) Systems Engineering and Design, 2) Fabrication and Integration, and 3) Testing and Documentation. Documentation will be compiled during all segments of the effort. CAD drawings of the design, transducer data collected in performance tests, and video recording will be used as portions of the final document package. The project is expected to require 21 months for completion.

Benefits:
The adaptation of cycloidal propulsion to VTOL aircraft would ensure excess power available in vertical flight, enhance VTOL UAV operating safety, and facilitate quiet flight operations. The commercial applications include near-term use on manned lighter-than-air vehicles, potential applications on manned VTOL aircraft and on commercial unmanned VTOL aircraft.

Keywords:
Cycloidal Propeller VTOL UAV Curtate Cycloid Cyclogiro Prolate Cycloid Cycloidal Propulsion Cycloidal Motion Vertical Take-off