Page 6 - Combined_140_OCR

U.S. g;al)) is pumped by two radial pumps through a high- The required quantity of cooling water, 10')0 m /h ('.' •
eapacity air cooler which maintains test airflow at the re­ 200 U.S. gal/hr) is cooled in a tower located ixm to un­
quired temperature. The effective surface area of thus wind runnel building.
tc SIX-COMPONENT BALANCE - A billy air■>m "••<-
■mllcd cooler is about 5000 5 (53,820 sq ft) (projected area:
component floor balance (manufactured by Ph t.cr ?'/•. Au//-:/
12.2 x 12.2 m (-10 x -10 ft)) and it is divided in its central
b g), in the form of a "floating" bal
horizontal plane and consists of 16 individual elements.
for measuring the aerodynamic forces mid m mu-; '.. a -tin
The structure of rhe cooler could be made relatively light
on test vehicles, The operating prii i
..J i
i _ ■
as the cooling agent (trichlorcthylcnc), unlike the refriger­
has proved most efficient over /die Last few y.-arn (Sc •. ii/s.
ant ITigen 22, is not subject to rhe Pressure Gas Regulation 3 and 4.)
so that only relatively small pipe, thicknesses were required. The wheels of the test vehicle arc secured to a floa'ing
As fa.r as the. control of the. refrigeration system is con­ frame which is supported on the bnsc. fraiim of the b:ibmcer
cerned. the. airflow must be cooled over the complete tem­ by means of four floating plates. The mourning pad; . >r die
perature range (-30 C (-22 F) to+50 C (122F)) used in the wheels lie. flush with the floor of the. working section. I'iie.
climatic wind tunnel. This means that the refrigeration polished floaime males arc located on top oi emm oth'-'
system must be. controlled within wide limits. The operat­ in {’airs, so that the. upper plate is. always screwe-l to the
ing principle of the- chosen method of control can be fol­ floating frame and th'-, lower one to the base Ira me. The
lowed without, difficulty on the. diagram in Fig. 2. When lower floating plates have cylindrical center holm; into which
full refrigeration output is provided, the pneumatic slide
pressure oil (approximately 7 am (113.7 psim)) is forced
valves 2 and 3 arc closed, while slide valve 1 is fully open.
with gear type pumps. 'Hie pressure oil flows out of die
'1’he full circulated quantity is thus cooled in the evapora­
cylindrical chamber through the gap between the floating
tor. At the other end of the scale, the regulating system
so that a sup]
has the function of defrosting the cooler which becomes an inch is formed between the individual pairs of floating
covered with ice in proportion to the initial humidity after plates, thus permitting unobstructed movement of die float­
the. guaranteed continuous operating period of 72hr. During
ing frame in the horizontal plane in relation to the base
this process, slide valves 1 and 2 are closed and slide valve
frame. In this way, a perfect scparatioi of acrody
3 is opened fully to pump hot trichlorethylene (up to 80 C drag and side force is acliicved.
(176 !■’)) into the cooler from heat exchanger 1. Normally, 'Hie floating frame is secured against the base frame with
the control system operates between these two limits so that three balance elements (for drag and side forces on the
slide valve 2 performs the function of a metering valve and front and rear axle) and three supports. 'Pile windforce de­
determines the ratio of the volumes of the circulating to the pendent displacement oi the flo. me secured to tiie
recooled cooling agent. test vehicle begins the measurin process even thougii the
■
Heat exchanger 1 performs another important function. displacement itself may amount only to small fractious of
With the heating system switched off, 15 m i960 U. S. an inch. The balance beam is withdrawn lrom ■ initial
horizontal position through a lever system as a. result o; dm
gal) of trichlorethylene can be. stored in this heat exchanger
at any desired temperature (between -40 C (-40 F) and load dependent displacement, Hie act: cd weighin', o '.na­
+80 C (176 F)) and fed into the cooling agent circuit through tion is carried out in accordance with the zero me died, by
means of which the balance beam is returned to dw initial
tile illustrated injector by dpenjn.g slide valve 3. Illis
horizontal position by displacing a sliding wei/.at. Tiiisg
achieves a rapid change in temperature.
icement o
which initiated the measuring process.

j

Fig. - A VW 1600 FL on the rotating six-component aero­
dynamic balance. View in air flow direction of the working Fig. 4 - View of tile nozzle from a VW 1600 TL. Square
section cover, collector and corner vanes steel frames arc fitted with turbul ■<. scr ens