Tale of Two Stingers

[larry cottrill]

Two new experimental fuel pipes, as shown in the macro photo below. My hypothesis is that it would be good to have fairly free flow around a spherical obstruction, to wit:

When air (or propane, presumably) flows around a spherical solid body, the flow divides on the upstream side very smoothly, flows around the sphere and rejoins in a fairly small turbulent region behind. This turbulent region can extend several diameters behind the sphere before is evens out. There is also a low pressure region centered just behind the maximum diameter of the sphere. So, if the low is a narrow stream of propane in the midst of free air, the air should be drawn into the stream all around the sphere in the low pressure region, and should be well mixed by the trailing turbulent flow. This is (almost) idealized by the left-hand example in the photo.

The right-hand example is an attempt to push the mixing action to the limit. The trailing half (almost) of the sphere is ground away to a flat plane. As the propane stream reaches its maximum velocity (and lowest pressure) it "spills over" the sharp edge into a large, highly chaotic region where mixing with the induced air should be excellent.

What do you think? The examples shown are 3/8-inch OD steel brake line with 3/8-inch steel balls welded in.

L Cottrill

[Viv]

Hi Larry

That's a very interesting idea you have there, that may have some legs on it too I think

Viv

[metiz]

Well one easy way to find out: hook up a propane tank and let 'er rip!

[larry cottrill]

Thanks, Viv! I love the beauty of simple things.

metiz, I will do that, indeed. I'm just waiting for the temps to come back up around freezing. Ha.

L Cottrill