Flow conditioning components, such as fine mesh screens and honeycomb modules, are essential elements in wind tunnel design to enable the flow to effectively be ‘straightened’. Flow Core Honeycomb can be manufactured in modules up to 2m x 2m.

Flow Conditioning Solutions

Flow conditioning devices are critical for achieving uniform, stable airflow in ducts, wind tunnels, and industrial systems. Cullum’s honeycomb flow straighteners and flow screens are complementary technologies that reduce swirl, turbulence, and velocity variations -delivering high-quality, repeatable flow performance.

All our flow conditioning solutions are engineered and manufactured in accordance with ISO 9001/14001.

Honeycomb Flow Straighteners

Cullum’s honeycomb flow straighteners are essential components in flow conditioning, typically placed upstream of the test section in a wind tunnel. Their primary purpose is to convert turbulent, swirling air—often generated by fan systems—into a highly smooth, parallel, and steady laminar flow, which is critical for collecting accurate aerodynamic data.

Cullum’s standard modular honeycomb solutions are precision-welded from corrugated ribbon sheets to ensure a consistent cellular matrix. All cell walls maintain perpendicularity to the flow face within +/- 0.15 degrees.

Typical honeycomb configurations are listed below, with additional options available to meet project-specific requirements:

• 10 mm (0.4 in) cell size with 0.15 mm (0.006 in) foil thickness
  Lengths: 100 mm (L/D ratio 10), 280 mm (L/D ratio 28)
• 7 mm (0.5 in) cell size with 0.15 mm (0.006 in) foil thickness
  Lengths: 115 mm (L/D ratio 9), 240 mm (L/D ratio 19)
• 15 mm (0.6 in) cell size with 0.15 mm (0.006 in) foil thickness
  Lengths: 150 mm (L/D ratio 10), 225 mm (L/D ratio 15)
• 16 mm (0.63 in) cell size with 0.2 mm (0.008 in) foil thickness
  Lengths: 240 mm (L/D ratio 15), 600 mm (L/D ratio 37.5)

Maximum module size: 2 m x 2 m (6.6 ft x 6.6 ft)

Cullum has provided honeycomb flow straightener solutions worldwide, to private and military customers alike.

Flow Screens

With extensive expertise in flow screen manufacturing, Cullum provides customized stainless steel flow screens for wind tunnel applications. Our solutions are utilized globally by top automotive and aerospace organizations, as well as premier research institutes.

Available in a range of configurations to meet project requirements:

• Aperture width: 0.003 (.001 in) mm to 10 mm (0.39 in)
• Wire diameter: 0.10 mm (0.0039 in) to 1.00 mm (0.039 in)

Other dimensions available upon request

Wind tunnels often report mesh screen seam issues like fraying, overlaps, or tape failure; these issues lead to localized flow disturbances, structural vibration, and pressure drop inconsistencies. To ensure uniform laminar airflow, seams must be perfectly smooth, tightly sealed, and structurally robust against aerodynamic drag forces.

Cullum’s flow screen seams are micro-plasma welded, creating highly concentrated, low-amperage arcs that are perfect for delicate mesh screens. It prevents wire burnout while delivering a narrow heat-affected zone (HAZ). This process yields cleaner, stronger seam joints that preserve the mesh’s corrosion resistance and flexibility.

In some applications, clamping and tensioning systems are required to maintain uniform load distribution across the flow screen and minimize metal fatigue. In these situations, Cullum provides project-tailored clamping and tensioning solutions.

Ready to optimise your wind tunnel design and implement advanced flow control technology? Contact us today to discuss your specific needs and find the perfect solution for your aerodynamic testing requirements!