Aerosonde UAV

Example simulation of the Aerosonde UAV (work-in-progress)

The Aerosonde is a small unmanned aerial vehicle (UAV) developed by InSitu, Inc. (later manufactured by Aerodonde, Ltd.) designed to collect weather data, including temperature, atmospheric pressure, humidity, and wind measurements over oceans and remote areas. See the Museum of Flight Aerosonde page for more information.

The Aerosonde UAV has a wing aspect ratio $AR=15.25$, wing area $S_{ref}=0.55$m$^2$, wing chord $c_{ref}=0.1899$m, and wing span $b_{ref}=2.8956$m [1]. The V-tail has a taper ratio of 1. A body-fixed coordinate system is placed at the nose. The reference speed is $|\mathbf{V}_{ref}|=25$m/s and the reference density, pressure and viscosity are evaluated at an altitude of $h=0$m (ISA). OpenVSP was used to create the mesh for the Aerosonde UAV. The figures below show the Aerosonde UAV geometry (left) and mesh refinement region and wake (right).

The wake's (shaded in yellow) purpose is to intersect the fuselage. This allows the potential jump across the wake to be resolved properly (i.e. without any numerical errors). The wake is removed by APM during the solution stage. APM only uses the pre-defined wake to determine the intersection location. The resulting mesh consisted of 31569 elements and is shown in the figure below.

Aerosonde UAV mesh created with OpenVSP

In the above figure, it can be seen that the wake elements were correctly determined by the APM preprocessor (see element types). These elements will be removed by APM during the solution stage.

Since the wake is expected to intersect the V-tail a solution where the wake extends to infinity (steady solution) is not applicable. Instead, a time marching solution is performed. Due to APM's hybrid formulation of the wake, a time marching solution allows the wake to intersect downstream surfaces (e.g. the V-tail). For more information see the interactions with the body section of the documentation.

The figures below show the pressure coefficient and the doublet potential.

Aerosonde UAV pressure coefficient

Aerosonde UAV doublet potential

References

[1] Sample model from the AeroSim Library, Copyright 2002 Unmanned Dynamics, LLC