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. Tunnel performance and calibration data are published in Bearden et al., 2022.

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-2023. 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 2 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)