Recent content by fastline

I guess I am second guessing the units here. Would you mind applying the math to my above figures? Would this indeed be k=.266 d=.120 k/d = 2.22BTU?

I am working on some basic calcs for heat transfer from polyethylene pipe. My numbers are not working out right so I need a little refresher. The PE pipe would have a TC of about .46 W/(m.*C). to get to BTU/(hr.ft.*F), I mult by .5779 to get .266. Assuming 10sf of PE pipe, and let's...

Thanks for that. From the calcs I have run, this structure of Al will not hold much energy as heat. However, more importantly, the dissipation. I determined the U value as 36 (btu/ft2 F)but I cannot remember if I would use the dT above ambient? IE Ambient is 100F structure is 110F...

I am curious if someone can help be estimate heat sinking and dissipation in an Aluminum structure? What I am trying to do is is cool a hot liquid by just allowing it to heat the structure it is in since there is a reasonable amount of mass. Though the Aluminum structure is not designed...

We have a vibration from a transmission that is showing up in some machined parts. We know the transmission needs to come apart but will need to schedule it for this summer. Has been this way for years. We need to find a quick remedy to at least reduce the problems. Transmission already sits...

here is a short list of options we have considered. Ethanol production from the heat energy from wind Hydrogen production from the electric through electrolysis Direct battery storage Hydro pumping (not practical in flat ground) Bio diesel lots of options but the battery just...

We are working on some design ideas to hopefully eventually get our shop and home off the grid with independent power. We are in one of the best locations for wind generation but energy storage becomes an issue and a grid tie system is simply impractical and will not obtain our goals. the...

Water "divining" or "witching". What is the basis behind it? Before I start, let me say that I am hugely skeptical but we do have an issue where finding a good hitting water well might be tough so thought I might check...lol For those that are unaware, people are basically using pieces of...

Condensation in certain cold weather conditions is our primary concern. It would not affect our circuits at all but does not project an image of quality. N is lighter than air so that would not fit our gravity fill considerations here. We are in a fairly humid climate several months out of...

We are working on an outdoor display unit. It will operate at a wide range of temps. There is not a requirement to purge air from the encasement but would be a smart decision I think. my thought was to use a gas that is very dry and heavy enough to simply purge the air and sit in the device...

I did some testing with PVC by adding to the end of the pipe and then a T where I can add variable lengths of piping. I am not real sure if this will prove out everything here but at my calculated 36" long which is 1/4 of the wave length, it did very little. When I pulled it down to 12" on...

I did not even think about a moment arm added with a mass on the end! That could really help. basically there is already a resonator muffler still in the system that was very likely tuned to kill most of the major problems from the engine. I am highly suspecting the active vibrations of...

I thought I would try to discuss this here since there seems to be a large misunderstanding in automotive forums and I want to learn the reality, not someone's theory. basically, I have a car here in which we removed one of the many mufflers. Piping is constructed as 2-1-2. It converges to...

Please again excuse my ignorance regarding pump design but for example, on a pos displacement pump, would the actual flow of the pump open air simply be expressed as swept volume x operating rpm x volumetric eff? Ie, is the swept, uncompressed volume an accurate way to estimate pumping ability...

So you are agreeing that centrifugal is ruling the roost in terms of eff at this point? It would sure seem that a high helix or more "gentle" compression would be ideal like a really high helix twin screw? Could a mono screw be a better design due to the elimination of the "paddling" effects...