A low-speed wind tunnel (≤100 m/s) and a high-speed one (≥343 m/s, supersonic) aren’t just “fast” and “faster”—they demand entirely different equipment. Choosing the wrong tools for your tunnel’s speed leads to bad data or broken gear. Here’s what to prioritize.

Low-speed tunnels (≤100 m/s) need:

· Probes: 3-hole or 5-hole pneumatic probes with plastic or aluminum tips (no need for heat resistance).

· Sensors: Basic pressure transducers (±0.1% error) and thermocouples (K-type works fine).

· Fans: Axial fans with variable speed (DC motors) for smooth acceleration.

· Software: Focus on steady-state data logging—no need for ultra-high sampling rates (100 Hz is enough).

High-speed/supersonic tunnels (≥343 m/s) require:

· Probes: 7-hole probes with Inconel or stainless steel tips (resist shockwave damage and heat).

· Sensors: High-frequency pressure scanners (≥10 kHz sampling) to catch shockwave spikes.

· Compressors: Centrifugal or axial compressors to generate high pressure (up to 10 atmospheres).

· Software: Burst-mode logging to capture transient events (e.g., 100 kHz for 10 seconds during a shockwave).

The big gotcha: Transition speeds (100–343 m/s):
Subsonic but fast enough to create compressibility effects. Use hybrid gear: 5-hole probes with heat-resistant tips, and sensors rated for 1–5 kHz sampling.

Cost comparison:
A low-speed setup (1m x 1m tunnel) costs $50k–$150k. A high-speed one? $500k–$2M—so getting the right equipment upfront avoids wasting budget.

Not sure which speed category your tests fall into? Share your max velocity, and we’ll list the essential gear.