Let's See If Vortex Generators Work??
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Joined: Nov 2004
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RE: Let's See If Vortex Generators Work??
Hey Magnuman,
Thanks for jumping on the sword!
Not a big fan of the look either but a HUGE supporter of your willingness to try something new and different.
Keep it up.!
KK
Thanks for jumping on the sword!
Not a big fan of the look either but a HUGE supporter of your willingness to try something new and different.
Keep it up.!
KK
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Joined: Nov 2004
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RE: Let's See If Vortex Generators Work??
For MagnumRT and cavu,
You may want to re-read my post on the results and look at the picture of what I am trying to get a little control of, dirty rear window. On the highway they do reduce the amount of dirt accumulation on the rear window. Not in town though. You may also want to read up on vortex generators, if you don't think they work. Guess they should take them off all the aircraft that they're on, too. Here's an article you can start out with: http://www.aerospaceweb.org/question...cs/q0009.shtml
Notice how nice the ones on aircraft look. Also, be aware that I am not trying to win a beauty contest with them, but they look better than the ones on the Mitsubishi and Suburu. I also didn't say I was in love with the way they looked either, but if they work, they'll stay. Oh, here's another site you may want to look at on how they don't work: www.airtab.com. Check out the video. Thanks for your input though.
You may want to re-read my post on the results and look at the picture of what I am trying to get a little control of, dirty rear window. On the highway they do reduce the amount of dirt accumulation on the rear window. Not in town though. You may also want to read up on vortex generators, if you don't think they work. Guess they should take them off all the aircraft that they're on, too. Here's an article you can start out with: http://www.aerospaceweb.org/question...cs/q0009.shtml
Notice how nice the ones on aircraft look. Also, be aware that I am not trying to win a beauty contest with them, but they look better than the ones on the Mitsubishi and Suburu. I also didn't say I was in love with the way they looked either, but if they work, they'll stay. Oh, here's another site you may want to look at on how they don't work: www.airtab.com. Check out the video. Thanks for your input though.
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Joined: Dec 2004
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RE: Let's See If Vortex Generators Work??
This subject was one of the largest ever at ********.com. They work. The question is to what degree. First of all, this is not an airfoil nor is it trying to be. That may be where part of the confusion lies.
Boiled down simply, it goes like this: The Magnum moves thru the air, displacing it. A lot of it. At the top and right/left sides of the Magnum, the Magnum's slice through the air is clean and stays roughly 'at altitude' (notice I am taking care not to say the air "shoots stright off the back" but thats how it looks if you diagram it with arrows). This causes a low pressure area immediately behind the vehicle that gets filled by the air just-displaced... and there's the problem, because the air coming from the bottom side (one side of four) has dirt and crud suspended in it. As this air is pulled up, the suspended crud is blown around and some lands on the car. Further, a disporportionate amount from the top especially does not fill the void for several feet given its flow characteristics. It reintegrates several feet back, leaving the bottom to take up the slack.
So the trick then is to 1) keep the low pressure area from forming behind the vehicle and 2) Break up the airflow from the other three sides so they fill the void and reduce the suction from the bottom.
VG's address both of these issues. Particularly #2. Short of using a wind tunnel, a great way to see this in action is to watch a Magnum on a rainy highway and watch the mist patterns.
Do VG's do an effective job? I don't think they do, personally. You'd have to plaster them along the sides of the car, I think, to improve what seems to me to be the meager gains you get from the top side. And as lots of folks know from that other forum, I find that a small handheld Makita blower applied for two seconds to the back end every day keeps me out of the car wash for a week.
Boiled down simply, it goes like this: The Magnum moves thru the air, displacing it. A lot of it. At the top and right/left sides of the Magnum, the Magnum's slice through the air is clean and stays roughly 'at altitude' (notice I am taking care not to say the air "shoots stright off the back" but thats how it looks if you diagram it with arrows). This causes a low pressure area immediately behind the vehicle that gets filled by the air just-displaced... and there's the problem, because the air coming from the bottom side (one side of four) has dirt and crud suspended in it. As this air is pulled up, the suspended crud is blown around and some lands on the car. Further, a disporportionate amount from the top especially does not fill the void for several feet given its flow characteristics. It reintegrates several feet back, leaving the bottom to take up the slack.
So the trick then is to 1) keep the low pressure area from forming behind the vehicle and 2) Break up the airflow from the other three sides so they fill the void and reduce the suction from the bottom.
VG's address both of these issues. Particularly #2. Short of using a wind tunnel, a great way to see this in action is to watch a Magnum on a rainy highway and watch the mist patterns.
Do VG's do an effective job? I don't think they do, personally. You'd have to plaster them along the sides of the car, I think, to improve what seems to me to be the meager gains you get from the top side. And as lots of folks know from that other forum, I find that a small handheld Makita blower applied for two seconds to the back end every day keeps me out of the car wash for a week.