Page 9 - Combined_26_OCR

are still not equal with the recommended package^ the difference between
the side forces has been greatly reduced or, in ether words, the aerodynamic
oversteer tendency has been decreased.

Figures 7 and 8 illustrate the individual effects of airfoil and stabilizers
respectively and were combined to produce Figure 6. The airfoil information
does not contain a curve for axial force coefficient vs. angle of yaw since
the airfoil effects do not significantly change during yaw. Side force vs.
angle of yaw is also omitted since the airfoil has no direct affect on base
vehicle side forces, The table shown below gives a more detailed breakdown
of Lift changes with changes in airfoil angle of attack.

THEORETICAL EFFECT OF REAR DECK AIRFOIL ON LIFT FORCE (CCB = -o.5°)

Airfcil Angle A Lift A Lift
of Attack Front Wheels Rear Wheels
CV-r (Degrees) (Pounds) (Pounds)

0 + 52 -171

-2 + 69 -230

-ll +86 -283

-6 +10il -3h0

-8 +121 -396

-10 +137 -Ui5 •

-12 +150 -W

-lb +161 -512

Airfoil COP. 2l+fI above deck lid and U?6>n from centerline of the rear wheels. ,

In the case of the stabilizer, only yaw data is presented since body.rake with
the stabilizer does not affect base vehicle lift and has a constant effect on
axial force coefficient (see angle of yaw = 0 for axial force effect).

WIND TUNNEL RESULTS ON REAR DECK AIRFOILS AND VERTICAL STABILIZERS <
--------—------------------------------------------- ------------------- --------- -- ----------------------------------
Figures 9, 10 and 11 contain a portion of the wind tunnel results obtained in
the recent tests conducted during March and April, 1969^ at Wichita-State
University. The airfoil discussed in Figures 9 and 10 and the stabilizers
discussed in Figure 11 are shown in Figure 1. They vary from the recommended
airfoil and stabilizers and a direct comparison of the data can not be made. '
However, the theoretically expected effects of the tested control devices
agreed rather well with the test results. This agreement adds increased
confidence to the theoretical approach used for the recommended control package.*

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