Why is it so that rain water is allowed to drop on the windshield and then swept away through the wiper?

Install vacuum blower on top end of the windscreen to suck all the rain water before it reaches the windscreen and discharge it sideways through water collection trough.
-- vedarshi, Aug 19 2019

https://www.driving...th-ultrasonic-tech/ [hippo, Aug 19 2019]

Wikipedia: Clear view screen https://en.wikipedi...i/Clear_view_screen
Mentioned in [pashute]'s anno [notexactly, Aug 22 2019]

Raindrops have a terminal velocity of 10-20mph. So, if you are driving at (say) 50mph, they will be hitting your windscreen at a shallow angle, not from above.

It might be more effective to have a blower along the bottom of the screen, to deflect raindrops up and over the car.
-- MaxwellBuchanan, Aug 19 2019


See attached link, which contains a very Halfbakeryesque quote: "The obvious way of doing it is to have an ultrasonic transducer in the corner of the windscreen that would excite waves at around 30kHz to bounce across the windscreen"
-- hippo, Aug 19 2019


What's a vacuum blower? Isn't a vacuum more of a sucker?
-- notexactly, Aug 20 2019


Rain-X anyone?
-- RayfordSteele, Aug 20 2019


Ultrasound to keep the rain off has been proposed many times (er... citation needed...), but no-one has been able to get it to work effectively on a car (works on a fighter plane because they go a lot faster).
-- neutrinos_shadow, Aug 20 2019


How about a transparent flexible loop that is constantly sliding across the surface of the windscreen. The return path of the loop is cleverly hidden in the roof of the car. There is a single stationary wiper on the side that scrapes the water off as the loop passes it.
-- xaviergisz, Aug 20 2019


If you can't change the speed, change the materials so they act like they are going fast. This would involve yet another film on the windscreen.
-- wjt, Aug 20 2019


in ships they have a rotating glass window that clears the water from the waves away.
-- pashute, Aug 21 2019


// How about a transparent flexible loop that is constantly sliding across the surface of the windscreen. The return path of the loop is cleverly hidden in the roof of the car. There is a single stationary wiper on the side that scrapes the water off as the loop passes it. //

Reminds me of my idea to keep snow off of solar panels. I don't remember if I ever posted that. If not, I should, but I don't think it's on my list. I'll check.

Edit: I haven't posted it, but it turns out to be on my list already, so I'll post it someday.
-- notexactly, Aug 22 2019


//waves at around 30kHz to bounce across the windscreen//

Of course, those words were (probably) not composed by anyone here, but I'm wondering whether they are meant to imply an in-and-out vibration, as of a drumskin, or a side-to-side vibration, as when one checks the unstiction of a frying pan before attempting a pancake flip.

In either case, would the purpose be merely to break surface tension so that gravity could do its work, or to fling water clear into the void by nothing but the energy of vibration?
-- pertinax, Aug 23 2019


//nothing but the energy of vibration// Really? or a layer on/close to the windscreen.
-- wjt, Aug 24 2019



random, halfbakery