Water vs Wind Dynamics

That’s true,

I had used CFD software to determine the efficient design for piping for cooling water piping as well as ducting for exhaust gases..

There are similarities for both, for the design, what I have found is there are at times where the similarities are nominal.

it all depends on the numbers and applications, such as volume (SCFM/ACFM for exhaust gases, GPM for fluids).

Well my first thought was One Second Plumber, but beyond the can, this is actually part of the answer I was looking for. In microclimate, atmospheric subsidence.

"Atmospheric subsidence is the downward movement (sinking) of air parcels in the atmosphere. It is the opposite of atmospheric lift. This movement compresses the air, which increases both the temperature of an air mass and its capacity to hold water vapour. The net effect is a lowering of an air mass’s relative humidity, and the dissipation of clouds and precipitation. "

https://avalanche.ca/glossary

"Sinking air parcels warm via compression and spread outwards upon reaching the surface of the earth. Resultant weather typically consists of clear skies and light winds, though exceptions do occur."

So this explains why a foothill, surrounded more or less by larger hills at varying distances, is significantly dryer and hotter than microclimates even a few km away.

This might also explain why, even in cloudy weather, the sky commonly clears and sun shines at least briefly around solar noon.

Because of the compressibility of air versus water as well as density of the matter, matters, such as supersonic speeds, are almost never dealt with in fluid dymnamics. Because of water's density, friction in water is so much greater. There are definitly many similarities, but the differences between in the phase of the matter (i.e. gas, liquid, solid) really does create significant differences that make comparison almost meaningless.

The other consideration is the ability to fill a container. The prefix <...hydro...> points towards liquid water, which will not completely fill any container unless sufficient is poured in; the prefix <...aero...> points towards air, which does actually fill any container it is presented with without more being introduced.

Such is the distinction between the liquid and the solid states of matter.

When there's too much water for the container it overflows. When it overflows it strictly follows the path of least resistance, whether the flow is laminar or turbulent.

Water interacts differently with the ground as well. Water displaces air in soil, when there's too much of it or it can't drain through, water fills the pores that contained air.

Air can only displace water by causing it to transition to vapor.

..."In physics, physical chemistry and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids — liquids and gases. It has several subdisciplines, including aerodynamics (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion)."...

..."The difference is that aerodynamics does not care about the gravity effects most of the time but hydrodynamics usually accounts for gravity effects"...

Everything is set in motion by heat, as the air heats it expands, as do liquids, so you have the heating air and water expanding and the cooling air and water contracting, they are both subject to the coriolis effect and density that drives the denser air and water to the lower portions and the less dense air and water to the surface area....All these imbalances put everything in motion, creating weather together with the gravitational pull of the planets, chiefly the Moon, that creates gravitational pull that bulges everything out in that direction...In a nutshell...

Great link, Rixter.

So kinematic viscosity of water vapor is approximately the same as for air, and both are invariably turbulent. Phenomena like 'straight line winds' or 'gap winds' are more turbulent if anything, due to the higher speed.

Ended up reading this Nav Canada document as well, which goes into some detail about the effects of topography on wind.

https://www.navcanada.ca/en/lawm-atlantic-en.pdf