Can a flow created by a fan show an Edge effect when hitting a wall?

[T C]

TL;DR

I want to know whether a flow created by a simple fan will show Edge Effect when hitting a flat and vertical surface.

We all know about Edge effect i.e. when an airflow hits the walls of buildings and its velocity will increase. Some market available shroud augmented wind turbine types are claiming that they used this effect to increase the output of their own designed wind turbine. But, all these are about natural wind flows. Now, let's think of a scenario that a simple table/stand fan is set before a straight and plain wall and it's switched on. I want to know that whether the flow created by the fan will show the same Edge Effect in this case just like the natural flows or not.

 

[Baluncore]

We all know about Edge effect i.e. when an airflow hits the walls of buildings and its velocity will increase.

No, we do not.
Are you suggesting that a sharp corner or edge will provide a source of eddies, because some corner is not sufficiently rounded to allow the Conda effect?

I think you need to attach a diagram, with some flow lines, showing at least a 2D view.

 

[Lnewqban]

Please, see:
https://www.sciencedirect.com/topics/engineering/boundary-layer-separation

The size of the straight and plain wall respect to the induced airstream should be an important factor.
The radial velocity of the air over the surface (in a direction perpendicular to the airstream) should get reduced as it flows away from the center of impact (as the volume remains equal).

 

[T C]

No, we do not.
Are you suggesting that a sharp corner or edge will provide a source of eddies, because some corner is not sufficiently rounded to allow the Conda effect?

I think you need to attach a diagram, with some flow lines, showing at least a 2D view.

That's the answer that I have got after asking Gemini. [AI reference link deleted by the Mentors]

Please, see:
https://www.sciencedirect.com/topics/engineering/boundary-layer-separation

The size of the straight and plain wall respect to the induced airstream should be an important factor.
The radial velocity of the air over the surface (in a direction perpendicular to the airstream) should get reduced as it flows away from the center of impact (as the volume remains equal).

Ok. Let's make it more precise. We have a 30 cm diameter fan fitted before a circular flat plate of 60 cm diameter and the centres of both are aligned. I want to know whether the flow will accelerate and will stick to the surface after the fan is switched on or not.

 

[Baluncore]

We have a 30 cm diameter fan fitted before a circular flat plate of 60 cm diameter and the centres of both are aligned.

What is the axial separation, between the fan outlet, and the circular plate?

 

[T C]

What is the axial separation, between the fan outlet, and the circular plate?

Suppose it's 10 cm.

 

[Baluncore]

Suppose it's 10 cm.

The outlet of the fan has an area of π * 15² = 707 cm².

The circumference of the fan outlet is π * 30 cm = 94.25 cm.
The area of the annular exit is 94.25 cm * 10 cm = 942.5 cm².

Since the annular exit has an area greater than the fan outlet, the air will flow at a lower velocity from the annular exit, than from the outlet of the fan. There will be a stagnation point in the centre of the plate, with air spreading radially, out across the plate. The air will not immediately wrap around the edge of the flat plate, but will continue to spread radially.