The Beagle Pup Flight Model for FlightGear.
Note this is not in the main FGAddon Beagle Pup model, however it is built upon this.
This aerodynamic model uses data and the engines model by Simon “bomber” Morley
Beagle Pup Geometry
Fuselage
- Length 18.23 ft
- Section 1 : X,Z 0.077 -0.01167, 1.60×3.05
- Section 2 : X,Z 5.39 0.19, 3.0×4.0
- Section 3 : X,Z 8.5 0.77, 3.4×4.1
- Section 4 : X,Z 10.23 0.6, 3.7×4.1
- Section 5 : X,Z 16.74 0.42, 1.99×1.39
Wing:
- span 31 ft
- chord 3.71869
- area 115.27 sqft
- NACA 63615 a=0.1, (T/C 0.14758, Ideal C/L 0.5806, A 0.141)
- root chord 4.768
- tip chord 2.67
- twist 0
- sweep 3
- Dihedral 7.37
Horizontal Stabiliser :
- span 11 ft
- area 29.4 sqft
- NACA 0008 (T/C 0.08387, camber 0) (NOT SURE ABOUT THIS)
- twist 0
- sweep 0
- Dihedral 0
Vertical tail:
- height 5.5 ft
- area 19.25 sqft
- NACA 0013 (T/c 0.129, Camber 0) (NOT SURE ABOUT THIS)
- twist 0
- sweep 0
- Dihedral 0
My model follows Rob McDonald’s advice of “(for VSP) with geometry less is more”; so the models are simple, using ellipses for the fuselage, and a low tesselation value. This is based on experimentation with low, medium and high complexity models. Something that looks right doesn’t necessarily generate more realistic data from VSPAero; and it is the geometry that is important rather than lining up with photographs. I’ve used a 3view photograph to estimate basic positions where measurements aren’t available, and then had to tune the exact positions based on the resulting coefficients.
With beta 5 I had to resort to some photogrammetry – simply because of a lack of decent data.
This is what I came up with – and I used this to tweak and align the geometry of the beta 5 version of the model.
Propeller effects
VSPAero includes rotor simulation, and this is used to generate a complete set of coefficient modifiers based on the propeller induced velocity.
Results and tuning.
I started to build the geometry on the 8th October, and the first flyable model took 4 days (mostly computational time); as there are geometric tuning that must be performed to balance the model.
A further week was required to tune the model, add the propeller and damage effects and to perform a few complete runs.
A full set of plots is available in my document Beagle Pup Aerodynamic Model
Calculating mass properties
VSPAERO Mass properties, component results
| Name | Mass | cgX | cgY | cgZ | Ixx | Iyy | Izz | Ixy | Ixz | Iyz | Volume |
| GearMain | 0.07 | 8.33 | 4.05 | -3.87 | 0.01 | 0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.36 |
| GearMain | 0.07 | 8.33 | -4.05 | -3.87 | 0.01 | 0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.36 |
| GearMainStrut | 0.00 | 8.32 | 2.56 | -2.83 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| GearMainStrut | 0.00 | 8.32 | -2.56 | -2.83 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| VTail | 1.37 | 19.93 | 0.00 | 0.33 | 1.90 | 4.59 | 2.74 | 0.00 | 1.11 | 0.00 | 7.13 |
| GearNose | 0.07 | 3.63 | 0.00 | -3.83 | 0.01 | 0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.35 |
| GearNoseStrut | 0.00 | 3.89 | 0.00 | -2.66 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| FuselageGeom | 16.54 | 9.31 | 0.00 | -0.14 | 26.18 | 243.71 | 248.00 | 0.00 | 2.87 | 0.04 | 119.02 |
| Wings | 3.76 | 7.72 | 7.30 | -0.79 | 55.17 | 3.62 | 57.43 | -0.57 | -0.10 | 5.60 | 19.60 |
| Wings | 3.76 | 7.72 | -7.30 | -0.79 | 55.10 | 3.61 | 57.37 | 0.57 | -0.10 | -5.56 | 19.60 |
| Engine | 5.25 | 2.68 | 0.00 | -0.22 | 2.48 | 3.50 | 4.40 | 0.00 | 0.00 | 0.00 | 6.73 |
VSPAERO Mass properties, results
| Name | Mass | cgX | cgY | cgZ | Ixx | Iyy | Izz | Ixy | Ixz | Iyz | Volume |
| Totals | 30.90 | 8.25 | 0.00 | -0.31 | 549.91 | 636.08 | 1145.26 | 0.00 | 17.29 | 0.08 | 173.16 |
Center of Gravity
| X | Y | Z | ||||||||
| 8.25 | 0.00 | -0.31 |
Moments of inertia
| Ixx | Iyy | Izz | Ixy | Ixz | Iyz | |||||
| 549.91 | 636.08 | 1145.26 | 0.00 | 17.29 | 0.08 |
Beagle-Pup Mass properties, 65 Slices.
200 Slices is more accurate; but in the end 65 is probably close enough.
Detailed Beagle Pup aerodynamic data plots
Beagle Pup model – drop in additions “FGAddon Beagle Pup” to add this FDM:
Simon Morley’s Engines – extract these into the FGAddon Beagle Pup. These are required.
Licencing information
- The Beagle-Pup from FGAddon is mainly authored by Richard Senior and licenced as GPL.
- Simon’s (T4T) Beagle-Pup is licenced as CC BY-NC-SA 3.0 (http://creativecommons.org/licenses/by-nc-sa/3.0/)
- My copyright on the files BeaglePup-vsp.xml, Systems/Beagle-Pup-controls.xml, Systems/Beagle-Pup-flight-controls.xml are all rights reserved, and are accessible, and may be distributed for purposes of academic review. I may well relicence my FDMat some point in the future if this turns out to be a viable BeaglePup model – however building a Beagle-Pup model is a side effect of this process and not the purpose of the process.