Question Aerodynamics for Small Flying Saucer

Spike Spiegel

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I'm working on a small (really small) flying saucer type craft. It's got roughly the same shape as the old Avrocar, but it's maybe half the size, with a bubble cockpit in the center. Very 1950's looking, and about the size of a Volkswagen. Two engines in the rear and three hover engines.

I'm using spacecraft3.dll to get the mesh into the sim, as this is my first foray into add-on development. I'm having trouble getting "realistic" aerodynamic properties, however. I'm not going for pure realism here, as I'd like it to have some decent handling in Earth's atmosphere, but it doesn't seem to respond as it should.

For example, it still glides fairly easily at about 60-70 m/s, even though it's basically shaped like a flattened little capsule. Also, when I launch it up to about 100km and let it drop, it rights itself before it hits the ground, sort of springing back up in the thicker atmosphere. It seems like it should drop more easily.

Here are the settings I've got so far.

SIZE=1.92
EMPTY_MASS=1875
FUEL_MASS=500
MAIN_THRUST=3.5e4
RETRO_THRUST=0
HOVER_THRUST=3.5e4
ATTITUDE_THRUST=2000
ISP=35000
PMI=(1.06,1.60,1.06)
TRIM=0.01

CW_Z_POS=0.09
CW_Z_NEG=0.09
CW_X=2
CW_Y=1.4

PITCH_MOMENT_SCALE=0.00005
BANK_MOMENT_SCALE=0.00005
ROT_DRAG=(0.10,0.13,0.04)
CROSS_SECTION=(4.07,11.56,4.06)

COG=-0.225

[AERODYNAMICS]

VAIRFOIL_ATTACK=(0,0,0)
VAIRFOIL_CHORD=3
VAIRFOIL_AREA=11.78
VAIRFOIL_ASPECT=1.45

HAIRFOIL_ATTACK=(0,0,-1.218)
HAIRFOIL_CHORD=2
HAIRFOIL_AREA=3
HAIRFOIL_ASPECT=1.5

; Control surfaces
ELEVATOR_ATTACK=(0,0.5,-2)
ELEVATOR_AREA=0.8
ELEVATOR_LIFT=1.2
RUDDER_ATTACK=(0,0,-1.35)
RUDDER_AREA=0.5
RUDDER_LIFT=1
AILERON_ATTACK=(0.6,0,-0.5)
AILERON_AREA=0.8
AILERON_LIFT=1.2
ELEVATOR_TRIM_ATTACK=(0,0,-2)
ELEVATOR_TRIM_AREA=0.8
ELEVATOR_TRIM_LIFT=1

Some of these numbers are guessed at, some are based on other small craft also designed using spacecraft3.dll. Hopefully someone can assist me. If you need any more information, let me know and I'll try to provide it.
 
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Scarecrow

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I don't think I can be of much help with the aerodynamics, but you wouldn't just happen to be making Spaceman Spiff's ship, would you?
 
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