Page 2 - Combined_124_OCR

S&M-/SM-48 May 22, 1968

L. G. Alexakos 4831 Spac a Huntsville
J. E. Vaughn 4831 Space Huntsville

ess on Wind Tunnel Tests of Automobiles

This is the first progress report on this activity; therefore, I will cover the
initial three weeks efforts. Weekly reports will follow from here-out.

Under*tandingly, the first several days were involved in orientation and being
brought up to date on the program. Efforts at that time were being made to
arrange for model construction. We, interested parties, made a field trip to
the proving ground on April 23, 1968 for the purpose of viewing and photographing
an actual race car which is in testing at the grounds. We found the trip
beneficial and took many pictures, but further decided that for authentic
reproduction of the car underbody, a prime necessity, the car should be made
available to the stylist during the clay mock-up period to take measurements
from and to make templates. Consequently, I have requested that the car be
made available to styling during the week of May 13, 1968. At this point it
looks as though we will get the car for the last two days of that week.

After initial discussions with the styling people and the plastics shop, the
people who will make the fiberglass shell from the clay model, a tentative
schedule was written for completion of work. This schedule was further
discussed with the people involved and, with their concurrence, published.
It calls for completion dates of the models (3) on July 8, July 18, and July 29.
Testing in the Wichita tunnel is scheduled to begin July 22, 1968.

Of secondary concern this early in the program was the need for a suitable
ground plane for testing. The g.p. used previously was a three-dimensional
one and unduly thick, causing excessive tunnel blocking. I suggested a
different approach to the problem, one which they liked. Upon discussion
with Marvin Davidson at Wichita University, he agreed that it was a good
solution and suggested someone come out there to solidify plans and construction
details. Therefore, on May 3, 1968, I held discussions with M. Davidson at
the tunnel and the construction details were finalized. The new ground plane,
which Davidson will construct, will be a two-dimensional one, less than 2
inches thick, approximately 6 inches off the tunnel floor and will allow the
model to be yawed without shutting down the tunnel. It will have a flap on the
trailing edge to allow the adjustment of the pressure stagnation point on the
board leading edge, and it will be capable of being extended into the tunnel
diffusor section to allow drafting studies (one car trailing another closely)
to be made.