Mach 5 Quiet Ludwieg Tube

Mach 5 Ludwieg Tube

Mach 5 Quiet Ludwieg Tube

QLT5 was installed in May 2019 and recently completed shakedown and calibration. It currently operates as a conventional tunnel and a quiet nozzle upgrade is currently in the fabrication stage and is expected to be delivered in mid-2022. Tunnel run parameters and instrumentation are given in the tables below.


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 32 ≥1 MHz bandwidth
Precision Filters 28612 programmable LP filter/amplifiers 32 f≤ 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)