Airflow Measurement, Flow Probes, Aerodynamics in Wind Tunnel
When most people picture a wind tunnel, they imagine a car sitting inside a room in front of a large spinning fan. That’s a reasonable starting point — but aerodynamic wind tunnel testing covers far more ground than that.
Wind tunnels are used to study the aerodynamics of airplanes, trucks, drones, rockets, racing cars, and virtually anything else that encounters air resistance. They range in scale from large enough to enclose a full-size vehicle to compact enough to evaluate a single component or scale model. The goal is always the same: to understand how air moves around a given object so that designs can be improved — whether that means better fuel economy, enhanced stability, or greater safety in challenging conditions.
To do that effectively, you need accurate measurements of pressure, flow velocity, and flow angle. That’s where precision flow probes come in.
Measuring Aerodynamics in a Wind Tunnel
Flow probes for wind tunnel testing
Multi-hole probes, Kiel probes, and yaw pitots are purpose-built instruments for measuring pressure, velocity, and flow angle in wind tunnel environments. A well-chosen probe takes fast, accurate measurements while remaining small enough not to disturb the flow it’s measuring — a balance that requires careful engineering.
K-Tec Systems is the authorized U.S. distributor for Aerosensor, a company founded by former Formula 1 aerodynamicist Dr. Barney Garrood PhD. Aerosensor’s instrumentation is built on decades of high-level motorsport, wind tunnel testing, and experimental aerodynamics — making their probes a strong fit for demanding professional applications.
Multi-hole probes
Aerosensor’s five-hole probes use five pressure measurement ports arranged around the probe tip to resolve the full three-dimensional flow vector. From a single probe position, you can determine total pressure, static pressure, and flow direction in both yaw and pitch — even in highly complex, three-dimensional flows.
Probes are manufactured using Direct Metal Laser Sintering (DMLS) additive manufacturing, typically in stainless steel. Titanium is available for weight-critical applications, and Inconel for high-temperature environments up to 980°C. Minimum probe head diameter is 2mm. An optional integrated static ring improves static pressure accuracy in low-pressure, low-velocity gradient conditions — useful, for example, on the nose of an aircraft or UAV.
Every probe is individually calibrated in Aerosensor’s in-house wind tunnel across five discrete flow speeds and over the full operating yaw and pitch angle range. Calibration data is delivered as simple lookup tables, ready for implementation in real-time systems or post-processing workflows.
For wind tunnel applications that also require air temperature measurement, K-Tec Systems manufactures custom thermocouples that can be integrated alongside flow probes to provide a complete picture of flow conditions.
Key specifications: ±0.25% accuracy, flow angles up to ±45°, maximum operating temperature 980°C.
Kiel probes
Where total pressure measurement is the priority — particularly in complex or high-angle flows — Kiel probes offer a distinct advantage over standard pitot tubes. A traditional pitot tube maintains accuracy only within roughly ±5° of the flow axis. The Kiel probe’s outer shroud realigns incoming flow with the internal measurement tube, extending accurate total pressure measurement to flow angles up to ±50°.
Aerosensor produces Kiel probes using DMLS technology, with tip diameters as small as 1.6mm. Available in stainless steel or Inconel, they are heat-resistant to 980°C. Standard configurations include the KP12 (1.6mm, 90° head), KP37 (1.6mm, 0° head), and KP57 (4mm, M4 thread, 0° head). Custom geometries and integration into larger assemblies are available.
Key specifications: ±0.1% accuracy, flow angles up to ±50°, maximum operating temperature 980°C, minimum diameter 1.6mm.
Yaw pitots
Yaw pitots measure both dynamic pressure and wind yaw angle simultaneously — and that combination matters more than it might seem. Aerodynamic forces are heavily influenced by yaw, which can reach double digits in ambient wind conditions. Without accurate yaw measurement in the field, correlating road data back to wind tunnel or CFD results is unreliable.
Aerosensor’s yaw pitots are produced in stainless steel using DMLS, with Inconel and titanium available for high-temperature or weight-sensitive applications. Each probe is individually calibrated across five speeds over its full operating angle range, with calibration data provided as lookup tables.
Key specifications: ±0.25% accuracy, flow angles up to ±30°, maximum operating temperature 980°C, minimum probe head diameter 3.6mm.
Kiel rakes in a wind tunnel
For applications that require spatial flow mapping — boundary layer profiling, jet engine exhaust analysis, or full-scale vehicle testing — Kiel rakes provide simultaneous multi-point total pressure measurement across a defined area, delivering the spatial resolution that single probes cannot.
Aerosensor’s Kiel rakes can be configured as one-piece monolithic DMLS structures or as machined assemblies using their KP59 Kiel probes with M4 threaded shafts. Both approaches allow the rake geometry to be tailored to your specific test setup, from compact temperature-resistant arrays for jet engine diagnostics to large lightweight configurations for aerodynamic flow profiling. Recent applications include on-track Formula One testing, haulage truck road testing, wind tunnel boundary layer measurement, and jet engine exhaust analysis.
Complementing the probes: the SC-01 pressure scanner
Probe accuracy is only as useful as the data acquisition system behind it. Aerosensor’s SC-01 is an 8-channel differential pressure scanner designed to complement their probe line. It measures true differential pressure at up to 1000 samples per second, with ±0.05% full-scale accuracy and exceptional zero stability over 24 hours. Data outputs via USB or Ethernet (TCP), and the included logging software works with any laptop or desktop.
Contact K-Tec Systems
Aerosensor’s probes are engineered for the measurement demands of professional aerodynamic wind tunnel testing — with proven performance in motorsport, aerospace, heavy vehicle, and UAV applications. As the authorized U.S. distributor, K-Tec Systems can help you identify the right probe configuration for your test environment. Contact us at 248-414-4100 or contact@k-tecsystems.com to discuss your application.
