2003-2004 Rochester Institute of Technology
Micro Air Vehicle Team
Airframe - Vehicle Configuration
A conventional aircraft design consists of a fuselage, wing and
tail, while a tailless flying wing design consists of only a wing
and control surfaces. The main drawback to the conventional configuration,
when considering the unique application of MAV's, is the minimal wing
area due to the addition of a tail. A flying wing configuration will
maximize wing area within a maximum linear dimension constraint, and
was therefore chosen as the vehicle configuration for RIT's MAV.
Using the above criteria, the list of potential airfoils was narrowed down to three.
The primary consideration when determining body shape is the need to maximize wing area while minimizing the largest linear dimension. This suggests that to maximize the available lifting wing area, the aspect ratio should be near one.
An extensive literature search of low aspect ratio wings led to four basic shapes; rectangular, Zimmerman, inverse Zimmerman and elliptical.
Materials and Fabrication
Many concepts for the design and construction of the airframe were considered, including:
Three different concepts were evaluated for the MAV's propulsion system. The major considerations for a successfully propulsion system are the thrust produced, power consumption, and overall system weight. The three types considered are rocket propulsion, and two motor - propeller combinations; one utilizing an internal combustion engine, the other using an electric motor. Two possibilities for the propeller selection are commercially available propellers or custom designed and manufactured propellers.
Using this criteria a weighted evaluation showed that the electric
motor/commercial propeller combination was the best option to pursue
The batteries will produce a 7.4 volt DC source. To provide the correct voltage to a majority of the electronics, a voltage regulator is necessary. It must source at least 1 amp continuously. The LM2940 is a logical choice because of its fixed voltage characteristics. The LM2940 can source one ampere at a constant five volts.
Three basic concepts for launching the MAV were considered. The first is a simple hand launch. This very simple method requires no equipment and little time. Unfortunately, hand-launching can be difficult to do successfully and repeatability is hard to ensure.
Another method investigated was a handheld launcher mechanism. Several hand-held devices exist for launching small aircraft. These have incoporated pneumatics, cross-bow type drawstrings, and even rubber bands.
Finally, ground and table based launcher mechanisms were considered. These provide a stable platform from which to launch the MAV. However, they also lose a degree of portability because of their size.
Copyright · 2004
RIT Kate Gleason College of Engineering and the RIT MAV Team.