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Richard Clark wrote in
: On Mon, 12 Mar 2007 07:29:09 GMT, Owen Duffy wrote: Owen Duffy wrote in : .... Classic work includes wind load, ice load, and temperature, with comined loads usually expressed in pounds per foot lengths. It is a tedious translation to check your page though. Try researching Pender and Thomson. .... Ok, so it is not for you apparently. Calculating wind loading of cylindrical wire is problem enough, ice loading might be cylindrical in laboratory tests, but is isn't reliably so in real life. The surface isn't necessarily smooth either (so the assumptions about laminar flow vs turbulent flow are affected). There has been much written on the effects of ice on HV power lines, where they can develop shapes that give them lift, with serious consequences when adjacent lines fly into each other. (Differently to antenna wire spans where wind load dominates the tension, large HV power conductors are so strong and heavy for their diameter, that high winds only marginaly increase tension, ice loaded spans are more affected.) However, if you want to model ice loading, just increase the weight per unit length of your wire for your chosen ice scenario, and increase the windage diameter, change the GBS if necessary for the lower temperature and run the numbers. I wouldn't propose an example, as I think the results are unreliable. The calculator probably has its greatest value as a learning tool in individuals exploring scenarios for themselves, they might come to the view that 160m dipole spans made from #16 magnet winding wire are not practical in high winds. Its not that we design to fail, its that we often fail to design. Owen PS: the calculator is metric units only to avoid the complication of comprehensively dealing with imperial units, eg dimensions in decimal inches, fractions, wire diameter in several gauge systems, lbs/mile etc, force in pounds, slugs etc. |
#2
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On Mon, 12 Mar 2007 20:10:10 GMT, Owen Duffy wrote:
Ok, so it is not for you apparently. Hi Owen, So you found the comments and references unappealing. Does that invalidate them being constructive? As you do not offer the mathematics to appraise, only a calculator to work; what constructive commentary did you expect when someone runs an example? The color of the box or the size of the font? 73's Richard Clark, KB7QHC |
#3
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Richard Clark wrote in
: On Mon, 12 Mar 2007 20:10:10 GMT, Owen Duffy wrote: Ok, so it is not for you apparently. Hi Owen, So you found the comments and references unappealing. Does that invalidate them being constructive? As you do not offer the mathematics to appraise, only a calculator to work; what constructive commentary did you expect when someone runs an example? The color of the box or the size of the font? I took your comments on board, and have made some changes. The mathematics aren't original or challenging, and in fact the results do show the detail of the model fitted to the data. The comments are appreciated though, thanks. 73 Owen |
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