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where does the high pressure air come from? |
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Maybe the air could simply be channeled from that flowing over the vehicle; the faster you went, the higher the pressure. |
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ato_de -> I guess from wherever is being redirected to my disk brakes. I suppose nichpo pointed the solution. |
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toejam -> I allways have a variation of that question on mind: could it be so difficult to blow the water way from the windshield? |
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Seems to me like you'd need compressed air. I don't imagine re-channeling the air moving past your car would be very effective.
+ |
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Reverse thrusters? I'd rather have itty-bitty cowcatchers. |
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I'm picturing a funnel in front of each front tire (looking like two extra headlights) - wide end facing forward, skinny end attached to a curved tube that points downward right in front of the tires. + |
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Kawasaki have famously been using ram-air systems on their sportsbikes for years (link). Not for blowing water out of the way, but for feeding the carbs faster. |
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Anyone know what kind of pressures this system generates and whether it would be powerful enough for this new usage? |
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Remember, the air is not "moving past your car" - the air is just sitting there relative to the road. |
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<Einstein>Actually, it is moving past the car, from the car's frame of reference. It's relative, you know.</Einstein> |
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[galukalock] - re frame of reference: We're trying to get the air to do work in the road's frame of reference. To get the air moving usefully relative to the road, the car must lose a lot of energy to the air. Put a snowplow blade on the front. Tip it forward and hold just above the road surface. |
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Also useful for those annoying speed bumps. |
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As [lurch] points out, the air is stationary relative to the road, as is the water. In other words, the air and the water are stationary relative to each other, so how will the air move the water? Any aero aids on the car its elf would need to return the air to the front of the car, by which time it would be too slow-moving to be of use. |
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*POP* Damn heat-rated tires at stop lights. |
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Ram air systems would have to have an appropriate cross-section to collect and pressurize the air in order to move water out of the way.
My approach:
Car is moving @ 60MPH, typical leaf blower blows @ 200+MPH.
Remember your air blast has to compensate for the speed of the vehicle, too, so let's round it off to 300MPH total air speed coming out of these jets...that means you'd have to have a scoop 5x the size of the area you're trying to clear (say 8" wide for the tire width, give it 12" of roadbed to actually have time to get stuff out of the way)...that's a hella scoop. Cross section = 480 sq. inches or 3 1/3 sq. ft.
I'm not sure, but for two tires, a 6 sq. ft. intake wouldn't leave room on most cars for a radiator grill. Stick to aquatreads. |
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Exhaust blowing forwards only to be run over by the tires or back into the intake for the engine...or better yet, coming back into the passenger compartment to kill you. In any case, exhaust wouldn't come close to providing enough airflow for high-speed clearance of water. |
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Exhaust gases have insufficient pressure to do the deed; they're deliberately de-pressured in the silencer (muffler) to reduce noise. |
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[reensure] has a point. How about a roller that runs just ahead of the main wheel, its purpose being to push standing water out of the way ? |
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Otherwise, if you go for an air-jet solution then I'd go with DrOuD's math; either you impose huge aerodynamic drag on the vehicle (with a wide aperture ramscoop and a profiled duct) or you use a Roots Blower (a huge power drain). The problem with the ramscoop is that if it's raining, the ramscoop will entrain even more water which you'll then have to extract somehow before you aim the jets at the wheels. |
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A solution might be a storage tank in the vehicle which is slowly pressurised by an engine driven pump triggerd by the windscreen wiper swithcm and then the jets only activate when you brake or corner, thus reducing overall demand on the system. |
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Another solution might be to use tyres with a significant depth of tread, and to drive in a manner appropriate to the conditions. |
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Most cars already have a huge forward-facing bucket on the front - it's called the engine compartment. Usually air flows through the grille, around the engine and out underneath the vehicle. If this air were channelled rather than being allowed to dissipate, would it serve the porpoise? It also has the added benefit of being pre-warmed by waste heat from the engine. |
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And Angel, where's the fun in that? |
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The tires themselves are moving fast; if a fan were placed inside the tire, air could be forced into a funnel mounted into the wheel. The funnel (turning with the wheel) would force air into a stationary tube in the axle, which curves around to direct the stream in front of the wheel. |
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As regards the calculation, it might no be necessary to have an 8 inch wide air blast - this is not a snowplow. A thin, fast stream of air would probably do the job just as well. This would be the sort of thing amenable to lab tests to determine at what point increasing the air pressure yields no additional benefit. |
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What if we were to try to (very) quickly heat the water in front of the car so that that it turns into steam? |
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Thanks [snarfy], I've always wanted a good excuse to mount flame devices on my car. |
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[bungston] - That's a very cool idea! |
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[snarfyguy] - Could a microwave minicannon work for that effect? Hmmm, maybe it takes too much power |
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Why not mount high-voltage electrodes on the front bumper to disassociate the water into a harmless mix of oxygen and hydrogen? |
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And trail it with a small flame to ignite the hydrogen, vaporizing even more water. Well, maybe not but at least create some fun explosions. Of course I don't envy a small animal that's caught in front of this contraption. <bzzzzt><pop><smush><smush> |
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Why not just get a rudder? |
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