Compact open circuit wind tunnels
Blower type wide-angle open circuit wind tunnel for propellers
We started this project because we needed an accessible facility to run dynamic tests on propellers.
When we kicked off the design in April 2025, our starting point was:
An existing blower-type fan with fixed performance and size.
Some available space in the underground floor.
That was it. With these two constraints, the requirement was to build a wind tunnel
capable of testing the largest possible propeller diameters at the highest possible speeds!
We started this project because we needed an accessible facility to run dynamic tests on propellers.
When we kicked off the design in April 2025, our starting point was:
An existing blower-type fan with fixed performance and size.
Some available space in the underground floor.
That was it. With these two constraints, the requirement was to build a wind tunnel
capable of testing the largest possible propeller diameters at the highest possible speeds!
The very first version of the tunnel:
The fan design forced us to place it at the tunnel’s inlet, while the room layout dictated an open-circuit configuration.
To achieve the best possible flow quality in the working section—meaning minimal turbulence and angularity—we needed a contraction section with the highest feasible area ratio. That, in turn, required a wide-angle diffuser to make the contraction fit within our limited space.
Step by step, the tunnel’s shape and size naturally emerged from these constraints.
What’s ready now:
Overall design and structural plans
CFD analysis of the tunnel and honeycomb
Current status:
The tunnel is under construction.
To achieve the best possible flow quality in the working section—meaning minimal turbulence and angularity—we needed a contraction section with the highest feasible area ratio. That, in turn, required a wide-angle diffuser to make the contraction fit within our limited space.
Step by step, the tunnel’s shape and size naturally emerged from these constraints.
What’s ready now:
Overall design and structural plans
CFD analysis of the tunnel and honeycomb
Current status:
The tunnel is under construction.
Our blower:
Next steps:
CFD analysis of the tunnel inside the room,
Purchase of pressure and velocity sensors,
Explore, improve, and manage the flow
quality in the working section,
and eventually
Test real propellers and enjoy the expansion
of our design capabilities!
CFD analysis of the tunnel inside the room,
Purchase of pressure and velocity sensors,
Explore, improve, and manage the flow
quality in the working section,
and eventually
Test real propellers and enjoy the expansion
of our design capabilities!
Next steps:
CFD analysis of the tunnel inside the room,
Purchase of pressure and velocity sensors,
Explore, improve, and manage the flow quality in the working section,
and eventually
Test real propellers and enjoy the expansion of our design capabilities!
CFD analysis of the tunnel inside the room,
Purchase of pressure and velocity sensors,
Explore, improve, and manage the flow quality in the working section,
and eventually
Test real propellers and enjoy the expansion of our design capabilities!
CADFlo CFD analysis:
Construction process:
Flow straightening and
turbulence management
To ensure uniform flow in the working
section, the tunnel is equipped
with four stainless steel screens and a
honeycomb section.
Screens (4 pcs): 1×1 mm mesh, 0.24 mm
wire thickness — porosity 0.61
Honeycomb: 19×19×150 mm cells, 0.45 mm
strip thickness porosity 0.93
This combination effectively reduces flow
angularity and large-scale
turbulence before the contraction.
turbulence management
To ensure uniform flow in the working
section, the tunnel is equipped
with four stainless steel screens and a
honeycomb section.
Screens (4 pcs): 1×1 mm mesh, 0.24 mm
wire thickness — porosity 0.61
Honeycomb: 19×19×150 mm cells, 0.45 mm
strip thickness porosity 0.93
This combination effectively reduces flow
angularity and large-scale
turbulence before the contraction.
Flow straightening and turbulence management
To ensure uniform flow in the working section, the tunnel is equipped
with four stainless steel screens and a honeycomb section.
Screens (4 pcs): 1×1 mm mesh, 0.24 mm wire thickness — porosity 0.61
Honeycomb: 19×19×150 mm cells, 0.45 mm strip thickness porosity 0.93
This combination effectively reduces flow angularity and large-scale
turbulence before the contraction.
To ensure uniform flow in the working section, the tunnel is equipped
with four stainless steel screens and a honeycomb section.
Screens (4 pcs): 1×1 mm mesh, 0.24 mm wire thickness — porosity 0.61
Honeycomb: 19×19×150 mm cells, 0.45 mm strip thickness porosity 0.93
This combination effectively reduces flow angularity and large-scale
turbulence before the contraction.
