SBIR-STTR Award

The ACRW is a revolutionary new design of a high speed, VTOL aircraft with STOL and CTOL capabilities. The aircraft consists of a circular rotating wing (CRW) which is rotably mounted to the fuselage. The CRW has the shape of a specially designed disk, is free of aerodynamically active flight controls or propulsion members and provides lift for forward flight and gyroscopic stabilization of the aircraft attitude. The fuselage will house the payload and the propulsion and control means. We have researched the ACRW aerodynamic theory, performed design calculations, conducted wind tunnel tests and computer analysis of the flow about the CRW. The wind tunnel tests and the computer analysis show a significant increase in the lift over drag when the wing is rotating as opposed to the fixed wing. Recently we have built two radio-controlled models and successfully investigated some of the ACRW flight characteristics. Bostan Research, Inc. is proposing to demonstrate the ACRW feasibility as a high speed VTOL UAV by testing three radio-controlled flying models. We have already built two new models and a third will be built during Phase I R&D. The models will have an identical configuration and mode of operation as the proposed ACRW-UAVs. The test results and flying principles will be equally applicable to aircraft of larger or smaller sizes having different configuration and uses. The enhanced aerodynamic characteristics together with the wing gyroscopic stability and artificial stiffening due to centrifugal forces, could make the ACRW the first truly efficient, high speed VTOL aircraft.

Keywords:
ACRW, VTOL, speed, maneuverability, stability, survivability, safety, economical

The main objective of the Phase II program is to build and test two high speed VTOL-UAV prototypes based on the Aircraft with Circular Rotating Wind (ACRW) concept. Prior to assembling the air vehicle Bostan Research, Inc. will conduct a detail design and performance analysis, wind tunnel tests, stability and control analysis, structural analysis and will test extensively Phase I models in free flight. Bostan Research, Inc. will purchase the components, build, assemble and shop test the air vehicles. The air vehicles will be tested on the ground and in free flight by AAI Corp. in conjunction with Bostan Research, Inc. Based on the Phase Ii work Bostan Research, Inc. will produce a detail ACRW UAV design and the theory that will predict its characteristics. The ACRW UAV free flight tests provide the most efficient and cost effective means in evaluating the aircraft characteristics throughout its flight envelope. At the completion of Phase II work Bostan Research, Inc. will integrate the ACRW UAV into an existing, operational, UAV system and propose a complete high speed VTOL UAV system to be built and tested during Phase III program. The proposed Model A is a high speed VTOL with CTOL capabilities. Model C has VTOL capabilities only. They are designed to operate safely and efficiently from available deck space on small surface combatants and from small clearings with little or no surface preparation before use. The ACRW UAV design ensures the safety and protection of operating personnel and nearby equipment, as demonstrated during Phase I free flight tests. Circular rotating wing provides in flight gyroscopic stability and as a result the gimbal stabilization equipment requirements for on board sensors will be minimized. Model A has 370 pounds gross takeoff weight, 100 pound useful payload capability, 152 knots cruise speed and 8.9 hours endurance. Model C is a low cost high speed VTOL UAV and has 210 pounds takeoff weight, 50 pounds useful payload, 160 knots cruise speed and 2 hours enduranc