The S3Ch wind tunnel is a continuous closed-circuit transonic facility running at atmospheric pressure. The air temperature is nearly the ambiant, being maintained close to a constant value during the tests by using a thermal exchanger device. The air flow is ensured thanks to a two-stage motor-ventilator group of 3.5 MW with a compression ratio of 1.25.
The test section is a guided one with sidewalls equipped with high-quality windows and lower/upper rigid or deformable adaptive walls (to follow the flow streamlines curvature around the model). Moreover, the facility is equipped with a sonic throat downstream of the test section in order to avoid pressure perturbations around the model in transonic regime.
Typical testing for dual civil/military applications are:
# wing-pylon-nacelle interference
# air intake efficiency of aircrafts
# buffeting on a turbulent and/or laminar airfoil and/or wing
# afterbody drag budget and jet signature of powered missiles
# base buffeting at the afterbody of a launcher
# Tunnel Square Test Section: 0.8m x 0.8m
# Test Section Length: 2.2m
# Stagnation pressure: atmospheric
# Stagnation temperature: ambient
# Mach number range: 0.2 – 1.3
# Maximum Reynolds Number/meter: 11.4 million
# Classical wall and field pressure / temperature (taps, probe, rake)
# Optical measurement techniques (PIV, LDV, uPSP, TSP, IR thermography)
6 hours x 5 days
(15-20 days maintenance stoppage per year)