Pr3ssure Posted September 30, 2018 Share Posted September 30, 2018 So I got some flex pipe and connectors so I can run it between my blower and tuyere. Was wondering if I should stretch it out, cut it and use as little of it as possible or if it would be fine just leaving length as is and just stretch accordingly. Not sure if the ridges created from it being all pushed together would slow the air down enough to matter. Quote Link to comment Share on other sites More sharing options...
Lou L Posted October 1, 2018 Share Posted October 1, 2018 Personally, I’d use it as is and stretch it only as needed in order to keep the shortest length possible. In my experience, those things go foul when stretched out and then cut. Also, the ridges are unavoidable even when it is full you extended and, in reality, if the negligible effect of resistance affects your blower enough to affect your fire then your problem is a weak blower. Quote Link to comment Share on other sites More sharing options...
Frosty Posted October 1, 2018 Share Posted October 1, 2018 Use it as is. If after using it for a while, months, years, ? you decide it's too long trim it to suit. I'm with Lou on this one. It's easy to shorten flex pipe and a PITA to lengthen it. There are ways to make extra length take up next to no room if it's getting in the way, it's FLEX pipe, you can wrap it around the blower stand or roll in under the forge or hang it on the wall ABOVE the fire pot so unburnt fumes can't collect. Whatever it can easier to a long piece out of the way and one that's just right. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Glenn Posted October 1, 2018 Share Posted October 1, 2018 Expandable metal dryer vent can be expanded as much as needed to get to point A to point B. Flexible means you do not have to be concern about alignment. Attach the pipe at the forge and leave the connection between the pipe and blower with a 3-4 inch or more gap or NOT connected. Aim the blower toward the open end of the pipe for more air, not so much for less air. Quote Link to comment Share on other sites More sharing options...
Pr3ssure Posted October 1, 2018 Author Share Posted October 1, 2018 Alright, just something that crossed my mind. Thought the ridges could hinder air flow. Almost completely setup though. Got my table top bolted to the frame. Quote Link to comment Share on other sites More sharing options...
Glenn Posted October 1, 2018 Share Posted October 1, 2018 You can drive yourself nuts by studying fluid dynamics and trying to chase down decimal points of air flow. What turbulence that is created in the ridges of the flex pipe, and the bends in the flex pipe, are offset by the ease of use. Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted October 1, 2018 Share Posted October 1, 2018 vector dynamics states the ridges will create turbulence, but its not going to slow down the air flow enough to matter Quote Link to comment Share on other sites More sharing options...
Charles R. Stevens Posted October 1, 2018 Share Posted October 1, 2018 Golf balls have dimples because the turbulence created acualy reduces drag. Sometimes turbulence is your friend . Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted October 1, 2018 Share Posted October 1, 2018 I thought they increased lift rather than decreased drag? Quote Link to comment Share on other sites More sharing options...
Glenn Posted October 1, 2018 Share Posted October 1, 2018 Golf ball dimples are used on all golf balls because a dimpled golf ball has less air resistance than a smooth ball of the same size and weight. This means less drag force and the ball going farther. The lower air resistance is because the golf ball dimples cause a turbulent boundary layer that stays attached farther around to the back of the ball, making a smaller turbulent wake , a smaller pressure drag coefficient, and less pressure drag force on the ball. In 1908, an Englishman, William Taylor, is credited with first manufacturing a golf ball having a dimpled surface. Quote Link to comment Share on other sites More sharing options...
Frosty Posted October 1, 2018 Share Posted October 1, 2018 Dimples are like turbulators on aircraft wings. As air flows over or past an obstruction, dimples, the little tabs riveted to aircraft air foil surfaces, ridges in air ducting say dryer ducting cause the air to flow over which causes turbulence and a boundary layer of low pressure bonded to the ridge. The low psi boundary layer is low friction, reduced friction means it flows more easily and faster. The increased lift where golf balls is concerned is caused by the rotation of the ball. The section that is rotating in the same direction as it is traveling against the air stream over the dimples so there is lower pressure and less resistance. The section that is rotating with the air stream encounters more friction and as it flows over the back air is dragged with it and downwards. This causes lift. There is a whole bunch of discussion of this effect among the new wave of lighter than air craft. There are designers trying to solve other problems with the rotating sphere lighter than air craft, as I recall, the gondolas tend to disrupt the air flow so they weren't living up to expectations. It's been a couple years since I did any reading about them but the aerodynamics of a rotating sphere through the air made perfect sense and stuck with me. It's how a pitcher can throw a curve ball, sinker, etc. otherwise a pitched ball would be on a ballistic trajectory rather than a dynamic trajectory. It's a really interesting subject you don't really need good math skills to follow along. Pr3ssure: Stop trying to figure this stuff out, the ONLY thing that means anything to you is: will it work. The answer is yes, it'll work just fine. On the other hand some of your questions lead to really interesting highjackable threads that won't do YOU one bit of good, we might enjoy them though. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
arkie Posted October 2, 2018 Share Posted October 2, 2018 Well, I think we aired out the problem with that air supply hose! Quote Link to comment Share on other sites More sharing options...
Lou L Posted October 2, 2018 Share Posted October 2, 2018 For what it’s worth, the Mythbusters used clay to put dimples on the exterior or a car and found it increased gas mileage. In a pickup truck it was found that the turbulence created by the open bed with the tailgate door closed actually increases gas mileage as well. A friend of mine is an engineer and, as a student at UCONN he was a co-writer with his preofessor on a study in which they studied the vector dynamics of air flowing over small gaps (valleys of different dimensions and shapes) in a steel plate. They found similar results. Depending on air speed and the shape of the impression it is common enough for the air to create a cushion that creates a zone of even pressure at the mouth of the gap. Just go ahead and use the flex duct as is Quote Link to comment Share on other sites More sharing options...
Charles R. Stevens Posted October 2, 2018 Share Posted October 2, 2018 So a car from Oklahoma is going to get better gas mileage than a car from say, California due to hail damage... Quote Link to comment Share on other sites More sharing options...
Frosty Posted October 2, 2018 Share Posted October 2, 2018 9 hours ago, Charles R. Stevens said: So a car from Oklahoma is going to get better gas mileage than a car from say, California due to hail damage... I believe so. If a person out west wants better mileage they should put marbles in their paint ball gun and get to work. Yes? I think we're onto something here gang, there's gotta be money in it! I'm beginning to envision a LOUD car wash type drive through. Ooooooh I feel riches coming! Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
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