A first test with pressure measurements on the primary mirror
was performed at the LASEN boundary layer tunnel as part of the
program for wind loading on the VLT telescope in a retractable
enclosure (cf. section 4.1.4).
The 1/80 model of the telescope was surrounded by a low platform
as it was at the time alternatively envisaged
for an open air arrangement of the VLT (fig.).
Figure: Distribution of pressure taps
and sectors on the 1/80 models of the primary mirror
Because of its sharp edges the mirror model was considered to be Reynolds independent. Two types of measurements were done: