The past weekend has not been good for flying; so more numbers were crunched and
more fairings were assessed; it was interesting to try some known shapes, no
shapes, different retraction heights, and an initial design developed way back
near the beginning of all this.
As usual the control piece was the standard mono in standard flight
configuration
at 100kt velocity (51m/sec). The airframe was stripped back to fuselage only
to reduce computer power and solving time. Several indicators were implemented,
Drag, Lift, Surface Velocity, Surface Acoustic Power... Fairings were tried
as semi and fully enclosed scenarios.
What the computer said...
The standard mono wheel, when retracted, skips on its tyre upon free stream air;
most all the remaining tyre remains within a protected pocket created by the
lower cowl deflector covering the muffler... employing a fairing does little
to reduce drag, however it does reduce acoustic noise within the undercarriage
well... a fully sealed fairing reduces this acoustic noise to near zero... the
variance upon drag factor between no fairing and fully enclosed is about 1kg
out of 38kg total; Lift variance is 1.8kg less with a fairing out of 7.8kg total
and is probably due to the tyre skipping on the free stream air... and thats
about it for the mono wheel faring with the ball ended enclosed shape providing
the best aerodynamic results.
Myth Busted...
Attached images relate to velocity and acoustic comparisons.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=510674#510674
Attachments:
http://forums.matronics.com//files/650ac4ad_8ace_4aa2_b79d_18796976a9cc_383.jpeg
http://forums.matronics.com//files/32e7836b_5949_4cbd_994b_39d722c8a709_207.jpeg
http://forums.matronics.com//files/aaa5982b_700b_4685_bd02_7070a8f2499a_758.jpeg
http://forums.matronics.com//files/51777a11_f283_4de4_977b_e4e25da175dc_170.jpeg
http://forums.matronics.com//files/1bda5df8_c3ac_4abe_9328_5eba78fd7649_689.jpeg
http://forums.matronics.com//files/5a94f80c_231a_48de_809f_756f92b4fb8d_119.jpeg
http://forums.matronics.com//files/1e525fe3_d8ab_46b6_80dd_80ab5445d0ca_191.jpeg
http://forums.matronics.com//files/469d3cbb_0ecb_4af7_9f9a_3b67e318f705_285.jpeg
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