Mach 5 Quiet Ludwieg Tube (QLT5)
QLT5 was installed in May 2019 and is undergoing shakedown and calibration. It currently operates as a conventional tunnel and a quiet nozzle upgrade is currently in the design stage and expected to be completed in late 2020/early 2021. Tunnel run parameters are given in the table at right.
Tunnel operating parameters
| Parameter |
Units |
Range |
| Mach number |
-/- |
5.0 |
| Quasi-steady run time |
ms |
100 |
| Test-section diameter |
mm (in.) |
381.0 (15.0) |
| Unit Reynolds number, Re' |
106 m-1 (106 ft-1) |
5.2–39.9 (1.6–12.2) |
| Total pressure, p01 |
kPa (psia) |
344.7–2068.4 (50–300) |
| Total temperature, T01 |
K (°F) |
385–450 (233–350) |
Tunnel instrumentation
| Component |
channels |
specifications |
| NI PXIe-6378 analog-to-digital converters |
32 |
16-bit, 3.57 MS/s/ch. |
| NI PXIe-6361 analog-to-digital converter |
16 |
16-bit, 2 MS/s |
| NI PXIe-4353 thermocouple blocks |
64 |
24-bit, 90 S/s |
| Precision Filters 28144 resonant sensor excitation |
28 |
≥1MHz bandwidth |
| Precision Filters 28612 programmable LP filter/amplifiers |
32 |
fc ≤ 3 MHz |
| Kulite KSC-2 signal conditioner |
4 |
Resonance compensation |
| FLIR X8501sc MWIR thermography |
1 |
14-bit, 1280×1024 px, 3.0 µm– 5.0 µm |
| Focusing schlieren (Photron FastCam SA-Z, Spectabit Optics) |
1 |
up to 1024×1024 px, up to 2.1M fps (reduced res) |
