Gas Barrage Engineers' Two i ind Tunnels Used
To Test Golf Clubs, Airplanes, Cars
Editor's note: The material for this
article was obtained from interviews
with Prof. Edward A. Stalker, acting
head of the aeronautical engineering
department this summer, and, Prof.
Milton J. Thompson of the same de-
partment.
By BETSEY ANDERSON
If you're having trouble with the
behavior of your golf clubs, keeping1
shingles on your roof, jumping out of
airplanes, racing cars, windmills,
yacht sails, smoke areas, streamlining
trains, or building airplanes and glid-
ers, the aeronautical engineering de-
partment of the College of Engineer-
ing can no doubt solve your problem
with the aid of their two wind tun-
nels located in the basement of the
East Engineering Building.
Not only that, but, in sharp con-
trast to the warm atmospheric con-
ditions outside, the two tunnels, one
a 50-foot long, 8-foot high model and
the other a smaller student model,
provide breezes which can be turned
on and off at will and can be regulat-
ed at any speed desired between the
range of 15 and 120 miles per hour.
However, at high speeds the tempera-
ture increases to a point about ten de-
grees warmer than the ou~tside air.
Breezes of all kinds are blown
through the pipelike chambers by the
engineers to test the practicability
and usefulness of various miniature
models made to scale. The tunnel is
so perfectly constructed that, if the
small model is made completely to
scale, all the necessary points may be
tested before the larger model is built,
thus reducing the cost of experiment-
ing on different shapes and varieties
at actual size. Consequently, much
more experimentation is made pos-
sible.
In testing a plane, for example, the
student works out all the necessary
computations and plans on paper, and
then builds a miniature model to scale
and places it on the three vertical
wires that hold it up in the tunnel
and tests its lifting power and re-
sistance.
The long rectangular tunnel con-
sists of three tubular chambers
through which the wind is blown.
The model is placed in the middle sec-
tion, hung from the ceiling by three
vertical wires, two of them placed at
the wings of the plane and one at the
tail.
Then the test is started and the
fan starts to 'suck in the wind, caus-
ing air currents to blow out in back
of it in somewhat the same manner
as if a household fan had been turned
backward. Thus, by holding the
model stationary and blowing air
past it, the same effect %is gained as
if the air were stationary and the
plane were dlying through it.
The air is sucked back into the
two other chambers, one on either
side of the fan and thus is continually
circulating during tests. Honeycomb
chambers in the two pipe-like outside
chambers keep the wind straightened
after rounding the corners and also
keep the speed uniform. The walls in
the two outside channels are plastered
to make them more smooth so the
air can go past them at a greater
speed.
As the test progresses, the charac-
teristics of the model at different
speeds and positions is worked out by
those taking part in the experiment.
At least two and usually four men
are needed to take care of the data.
The tunnel is one of the few of its
size in operation in the country, the
number probably not exceeding more
than 30 at, the most, although there
are quite a few smaller ones used
mainly for demonstration rather than
testing purposes. Most of them are
maintained by universities and the
model at Michigan possesses the repu-
tation of being perhaps the most out-
standing in the Middle West. It is
a model of the double return type.
A force of 50 policemen and deputy sheriffs, recruited from North Shore towns, used a barrage of tear
gas to drive between 400 and 500 strike demonstrators from the plant of the Chicago Hardware Foundry
Co. in North Chicago, Ill. The strikers are shown here in retreat, water-soaked handkerchiefs clasped to their
faces.
lIj
F - ~------ --_--
:r.
-
e
te
Ve
HUGE OUT-OF-DOOR CONCERT
215 MUSICIANS
University Summer Session Band
High School Clinic Band
Conductors:
/
WILLIAM D. REVELLI,University of Michigan
GERALD R. PRESCOTT, University of Minnesota
-Hear Sousa's "Stars and Stripes Forever"
played by this great musical aggregation.
Friday,July
F ERRY
29,,7 P. M.
FIELD
O.D.MORRILL
314 S. State St.
Typewriters, Stationery,
Studernt andiOffie SunnGies
Saffel andBush
No Admission Charge
In Case of RAIN, the Program will be given in Hill Auditorum at 8:30 P.M.
""" * "JP" """ i 1 V . 0 E M N T E! L L Sb A N Q T H E R " ikf
Since 1908 Phone 6815 _____ _ l
._,
FOR
W
MICI-IIGAN
MEN'
. 0 0
MAKE THE TAP ROOM YOUR EATING HEADQUARTERS
)MF FOOD AMAR F FAR YnA IR DnT T.A R CFNTR ALLY LOCATED
.
+r/
HOT ESC
N aIs ~U 11
I