> A great illustration is to drive your car thru a very heavy fog
> and notice that today's cars windshield still gets wet.
> The water droplets in fog are way less mass than the smallest
> insect, yet have enough mass to penetrate the boundary layer just fine.
I don't think mass is the crucial factor- I think it would be better viewed
as a mix of surface area and density.
The droplets of water in fog are perhaps 10 to 15 microns in diameter, but
they still have the density of... well, water, and a minimal surface area
(sphere).
Insects have wings, and antennae, and are little flying machines, so they
have lots more flight-enabling surface area and surfaces, and an overall
density lower than that of a water droplet.
They also have, relative to their size, very large air sacs along their
tracheae, so they contain air, further reducing their density when "on the
wing".
In this scenario, at anything above 35 mph or so, an insect is akin to a
paper airplane, while a fog droplet is akin to birdshot.
"Laminar airflow" is the effect that designers design for. Even Volvos are
all curved surfaces, and airbags, and computers these days.
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