Considerations about general arrangement of the airplane.

Final arrangement of the UAV with a fuselage new design

After speaking, during the preceding entries, in very general terms, it is time to present a more detailed description of the preliminary design solutions, element by element.

Wings:

Straight trapezoidal: Easier construction, good behavior at moderate speeds (up to Mach 0.3). With a taper ratio of approximately 0.44 provides a near elliptical lift distribution, minimizing the induced drag.

High aspect ratio (near 20): Less drag for the same wing surface. Not too high in order to avoid structural problems.

Use of Winglets: Less drag and better aerodynamic efficiency.

Under fuselage construction: Better compatibility with horizontal stabilizer and easier integration of the landing gear system.    

Wing and horizontal stabilizer diagram

Body:

Circular cross sections: Due to the moderate width of the body these kind of sections provide some constructive and operational advantages without compromising the drag.

Front body wider and rounded: More space available for payload. The rounded surfaces allow better performance of optical and radar-based devices.

Rear body adapted for propulsion: The main section width is determined by the engine dimensions. The rear pusher propeller, with its body-centered axis, allows to reduce drag and cause less interferences with the navigation avionics and payload. The air intake is situated over the fuselage providing a cleaner airflow, especially during take-off.

Lateral view of the aircraft

Tail:

H configuration: Trying to avoid interferences between the tail and the rear mounted turboprop. Also allow that longitudinal and lateral stability problems could be solved separately.

Aerodynamic interaction between the wing and tail.