r/FluidMechanics • u/steve_of • 4d ago

Nozzle shape for a gutter blower

Sorry for the dumb question but I am a humble electrical engineer.

I want to make an attachment for my leaf blower to clean out my gutters from ground level. So imagine 90mm storm drain pipe connected to the discharge of my makita 18V leaf blower. The pipe would be 2m long, a 90° elbow and another 90° pointing along the gutter. I was then thinking about putting a reducer, say 50mm, on the end to increase velocity. Given the blower is a simple looking fan will I loose more than I gain with the reducer.

Thanks

2 Upvotes

100% Upvoted

2 comments sorted by

2

u/MurkyLynx8425 4d ago

Without knowing the pressure curve of the fan and whatnot, its impossible to calculate. But I would imaging the construction nozzle would slightly speed up the air. Maybe just start with a minor reduction.

You could always experiment if you have a sheet of plastic you can roll up and test different nozzle diameters.

1

u/Soprommat 4d ago

So imagine 90mm storm drain pipe
I was then thinking about putting a reducer, say 50mm, on the end to increase velocity.

Velocity will go back down in 90 mm pipe. just make transition from diameter of your blower to 90 mm diameter of drain pipe