An Aerodynamic Assessment of Micro-Drag Generators (MDGs)
Commercial transports as well as fighter aircraft of the future are being designed with very low drag (friction and pressure). Concurrently, commuter airports are being built or envisioned to be built in the centers of metropolitan areas where shorter runways and/or reduced noise footprints on takeoff and landing are required. These requirements and the fact that drag is lower on new vehicles than on older aircraft have resulted in vehicles that require a large amount of braking force (from landing-gear brakes, spoilers, high-lift flaps, thrust reversers, etc.). Micro-drag generators (MDGs) were envisioned to create a uniformly distributed drag force along a vehicle by forcing the flow to separate on the aft-facing surface of a series of deployable devices, thus, generating drag. The devices are intended to work at any speed and for any type of vehicle (aircraft, ground vehicles, sea-faring vehicles). MDGs were applied to a general aviation wing and a representative fuselage shape and tested in two subsonic wind tunnels. The results showed increases in drag of 2 to 6 times that of a "clear" configuration.
AIAA-2001-0253 FLIGHT CONTROL OF A SPIN STABILISED AXISYMMETRIC DISC-WING
A review of air-vehicles with circular planform ie discwings includes examples of mid-20 century innovation and recent developments in UAV (unnamed air vehicle) technology. A spin stabilised axi-symmetric disc-wing has potential application as a highly manoeuvrable, unpowered unmanned air vehicle or guided projectile. This paper considers the means by which aerodynamic control moments can be generated on such a disc-wing. The present experimental investigation outlines the aerodynamics of a spin stabilised axi-symmetric discwing and documents the aerodynamic differences of a disc-wing with forced transition strips installed on the disc rim. It is proposed that these differences are achievable by a similar active flow control method such as active turbulent strips, vortex generators or synthetic (massless) jets as a means to aerodynamic control of the disc in flight. A simple analysis of disc-wing flight manoeuvres predicts the turning radius and time period of a 90° banked turn based on experimental data.
Fully Integrated Bidirectional CMOS-MEMS Flow Sensor With Low Power Pulse Operation
Leveraging More-than-Moore technology, we demonstrate an integrated CMOS MEMS flow sensor via a very compact system on chip (SoC) that can sense the bidirectional N2 gas flow. Our SoC features a very low-noise instrumentation amplifier that is implemented on a CMOS wafer and serves as a readout integrated circuit for a thermoresistive micro-calorimetric flow sensor which is fabricated on a MEMS wafer. A compact heterogeneous integration is achieved by combining the two wafers via the proprietary InvenSense AlN process. The measured sensitivity of our CMOS MEMS flow sensor is 98 mV/sccm which is three times better than the state-of-the-art counterpart. The flow range measured by our SoC is from −26 to 26 m/s (from −50 to 50 sccm). Moreover, the pulsed heater operation makes this proposed SoC flow sensor a very low power (<9 mW) and, thus, a promising candidate for the Internet-of-Things applications in smart home/green buildings.