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Wolfgang Morchen
Volkswagcnwerk AG

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;.T-I\Ci\.PASlNG demands made on the modern car FUNCTIONS OF WIND TUNNEL
bv DOI c traffic must be met by automobile man
umeturers and involve an mtensilicacion oi testing opera- The main objective in planning VW's climatic wind
tions. Tiius, new measuring' methods have to be developed. tunnel was to create one which would still be considered
These methods require expensive and higlily sensitive meas­ modern 10 years after its completion.
uring i.istrumentb and methods which arc already used in The main technical objective was construction of a com­
the field of aircraft and space research and which now have bined "large-size test bed" on which, in addition to aero­
been adapted to the special requirement of automobile dynamic tests on full-scale vehicles, a large number of
development. functional tests could be carried out. These functional tests
The size, weight, and sensitivity of precision instruments require development of true airflow conditions around the
of this type virtually prohibit their use in test vehicles oper- test vehicles and the simultaneous reproduction of precise
racks or i ids. < mnscquetil l.y, the use of test cham­ engine output These tests arc used mainly for research
bers for automobile cngiuccriiig research has great iy in­ into engine cooling, air conditioning, and heating tyid ven­
creased in recent years'. tilating of passenger compartments.
A imine, reason for trans for ring test operations from road Decisive factors in Volkswagen’s decision io construct
to te member is the increasing traffic density which scri- a climatic wind tunnel for full-scale test vehicles were, that
out de Icst programs. More­ maximum testing accuracy can be achieved only by using
over, the testing of prototypes on public highways is prac- full-scale models and because experience in automobile
ible because o ■ d< :e for secrecy. production has shown that it is extremely difficult to trans­
Thom reasons led Volkswagenwerk's board of managc- fer accurately to full-size vehicles the quantitative test
pla i c< struction oi a climatic wind tunnel. results obtained with scaled-down models. Tliis is due to
The m ■ ..a ••assigned to Dingier AG, Zweibrucken, well-known functional considerations in automobile design and to the
in tjm field. large number of similarity parameters which must be met.

(93 mph). The size of the working section permits tests
to be carried out on full-size car models. Functional tests
cen . main plant in W Lisburg. A climatic wind can be performed with a program-cont rolled dynamometer
uwcrk AG is constructing a major research
Lm.ici, trie most modirn of its kind in Europe, has already test bench. They include testing of engines under actual
b • ,n commoted. With VW exports going to almost every road loads and cooling conditions and the testing of heating
?-iy i.i :ih- world/the inimel has been designed lo simu- and air condithMing systems. Aerodynamic forces to which
Ln.: .ild ..oris <>f cliin.itic-coiaiiti<>ns, including the. aiinos- a car is subjected can be measured with a mechanical ro­
:i< ic..e>cr.ii ;.< •. .mJ humidities of all mam climatic tating six-component balance. The. operation of the. entire
me:., iVgcthcr wit.li an immiic variation oi those. <.'ondi- installation, data logging and data processing, is carried
o..., inc. tunnel can develop wind speeds up to IbO km/h out automatically by means of a computer.