For the diy'sFound this paperPlease have a look for interest sake, and I would make the same recommendations stated.the need to place 'a gap at the bottom' of a rack to the first electronic amplifier component for increasing the free air movement and whether we could do the samething could apply to test setups involving magnetrons. There are also some do's and don't do that could be useful as wellI'm of the thought, that targeting "thermal air eddy elimination" will bring everybody a better and more accurate results in that desire to isolating out the direct EM Drive effect by removing or at least minimising and/or linearizing the thermal noise component for easier isolation and removal. I like the quote earlier on a few pages back"A surrogate to noise is the standard deviation or variance."so its logical to minimise it.Schlieren Optics is tell us its there... but that we just cannot see it yet... [thermal air eddies and noise]much like turbulence you experience in an air planeOne other thermal management reference's pointed to using rectangular slotted holes as being better than round holes for purposes of easy air flow that's why you find slots in more common use on computers.and yet another promotes what is called 'pin finning' instead of normal finning on Electronic chipshttps://en.wikipedia.org/wiki/Thermal_management_of_electronic_devices_and_systemsand how about fin orientation vertical vs horizontal?another one of those things to ponder about
Quote from: Silversheep2011 on 10/03/2015 01:49 pmFor the diy'sFound this paperPlease have a look for interest sake, and I would make the same recommendations stated.the need to place 'a gap at the bottom' of a rack to the first electronic amplifier component for increasing the free air movement and whether we could do the samething could apply to test setups involving magnetrons. There are also some do's and don't do that could be useful as wellI'm of the thought, that targeting "thermal air eddy elimination" will bring everybody a better and more accurate results in that desire to isolating out the direct EM Drive effect by removing or at least minimising and/or linearizing the thermal noise component for easier isolation and removal. I like the quote earlier on a few pages back"A surrogate to noise is the standard deviation or variance."so its logical to minimise it.Schlieren Optics is tell us its there... but that we just cannot see it yet... [thermal air eddies and noise]much like turbulence you experience in an air planeOne other thermal management reference's pointed to using rectangular slotted holes as being better than round holes for purposes of easy air flow that's why you find slots in more common use on computers.and yet another promotes what is called 'pin finning' instead of normal finning on Electronic chipshttps://en.wikipedia.org/wiki/Thermal_management_of_electronic_devices_and_systemsand how about fin orientation vertical vs horizontal?another one of those things to ponder aboutNice info! I have decided to construct a home-built Schlieren Optic system over the next several weeks to analyze the NSF-1701 assembly, under power and not on the balance beam. I will video this.
Quote from: rfmwguy on 10/03/2015 03:38 pmQuote from: Silversheep2011 on 10/03/2015 01:49 pmFor the diy'sFound this paperPlease have a look for interest sake, and I would make the same recommendations stated.the need to place 'a gap at the bottom' of a rack to the first electronic amplifier component for increasing the free air movement and whether we could do the samething could apply to test setups involving magnetrons. There are also some do's and don't do that could be useful as wellI'm of the thought, that targeting "thermal air eddy elimination" will bring everybody a better and more accurate results in that desire to isolating out the direct EM Drive effect by removing or at least minimising and/or linearizing the thermal noise component for easier isolation and removal. I like the quote earlier on a few pages back"A surrogate to noise is the standard deviation or variance."so its logical to minimise it.Schlieren Optics is tell us its there... but that we just cannot see it yet... [thermal air eddies and noise]much like turbulence you experience in an air planeOne other thermal management reference's pointed to using rectangular slotted holes as being better than round holes for purposes of easy air flow that's why you find slots in more common use on computers.and yet another promotes what is called 'pin finning' instead of normal finning on Electronic chipshttps://en.wikipedia.org/wiki/Thermal_management_of_electronic_devices_and_systemsand how about fin orientation vertical vs horizontal?another one of those things to ponder aboutNice info! I have decided to construct a home-built Schlieren Optic system over the next several weeks to analyze the NSF-1701 assembly, under power and not on the balance beam. I will video this.Hook up those dual muffin fans like I suggested, if you wouldn't mind, blowing horizontally off from the top.Shell
Quote from: SeeShells on 10/03/2015 04:52 pmQuote from: rfmwguy on 10/03/2015 03:38 pmQuote from: Silversheep2011 on 10/03/2015 01:49 pmFor the diy'sFound this paperPlease have a look for interest sake, and I would make the same recommendations stated.the need to place 'a gap at the bottom' of a rack to the first electronic amplifier component for increasing the free air movement and whether we could do the samething could apply to test setups involving magnetrons. There are also some do's and don't do that could be useful as wellI'm of the thought, that targeting "thermal air eddy elimination" will bring everybody a better and more accurate results in that desire to isolating out the direct EM Drive effect by removing or at least minimising and/or linearizing the thermal noise component for easier isolation and removal. I like the quote earlier on a few pages back"A surrogate to noise is the standard deviation or variance."so its logical to minimise it.Schlieren Optics is tell us its there... but that we just cannot see it yet... [thermal air eddies and noise]much like turbulence you experience in an air planeOne other thermal management reference's pointed to using rectangular slotted holes as being better than round holes for purposes of easy air flow that's why you find slots in more common use on computers.and yet another promotes what is called 'pin finning' instead of normal finning on Electronic chipshttps://en.wikipedia.org/wiki/Thermal_management_of_electronic_devices_and_systemsand how about fin orientation vertical vs horizontal?another one of those things to ponder aboutNice info! I have decided to construct a home-built Schlieren Optic system over the next several weeks to analyze the NSF-1701 assembly, under power and not on the balance beam. I will video this.Hook up those dual muffin fans like I suggested, if you wouldn't mind, blowing horizontally off from the top.ShellI'm glad to see its of interest to both seashells and rfmguy but I can see possible trouble with that arrangement shells...while I'm enjoying morning coffee, and looking over sketch's it appears there is the makings of an airplane wing here the same effect as blowing over top of a sheet of paper - could be mild lift but I'm sure its there.So up for some ideas?1. start by allowing some air space "under" the magnetron so that it disconnects it from the top plate sheet surface perhaps use some adjustable spacer legs2. consider using he balance beam to find a counter lift angle could be found by adding a few degrees say it works out at 1°-2° of down rake via the adjustable legs to counter balance out any lifting force being generated by the cooling fans. looks like it could be a very much likely to be trial and error approach for a while. I do give credit though, blowing through sideways seems to be the best mounting direction for fans compared to top and bottom mounting fans.there is another aspect to think about on this issue: all the heat has go 'somewhere' and that 'somewhere' has to be dissipated heat into air, there is simply no other path.- its going to mean a lot of hot air going up, and a lot of cold air going down.-
Quote:"The magnetron is rfmwguy's main issue with hot air eddies rising vertically up from the frustum. this creates a low pressure directly above the frustum and the air below the frustum gets pulled along the sidewalls to fill the void. Chaotic actions occur because of the pressure differentials between bottom and top.By blowing the thermal heated air to the side it can be allowed to rise without adding a chaotic component to the frustum."Seashells, Agree with comment- and on further thinking about it. Wouldn't it make sense to test with the magnetron Off, and the cooling fans On first in the actual beam configuration as part of a mock up in a calibrating pre-run? and see what the numbers say?if there was no noticeable movement up or down, or oscillations, with fans On only operationyou would have to say only then that's its onto a "good thing" to do as a standard part off the setup on EMD runs [run cooling air sideways to magnetron with cooling fans], if correct. And if not, well it means looking for other alternatives or ways to mitigate those thermal and air movement effects?
Please don't waste time increasing airflow across the magnetron. Pressure/lift is related to velocity squared, and the fans blowing any air around the magnetron will create chaotic air currents with orders of magnitude more force than relatively slow thermal air currents.
In reply to shell: Assymetric horizontal airflow creates lift. Since the magnetron is not a symmetric airfoil, it will have chaotic, turbulent airflow around it at best. Characterizing the resulting forces accurately enough to discern an underlying mN signal under it would be difficult.Considering that, work to streamline the magnetron may help regulate the lift and drag from the convection currents.
Quote from: cl33250 on 10/04/2015 06:19 amPlease don't waste time increasing airflow across the magnetron. Pressure/lift is related to velocity squared, and the fans blowing any air around the magnetron will create chaotic air currents with orders of magnitude more force than relatively slow thermal air currents.I would agree the horizontal fans may increase the chimney effect and create unwanted horizontal oscillations. Thermal plumes can only be controlled by ambient air temp equaling device temp...or vacuum testing.This thought experiment has kept me up at nights...finally thought it best to not add anything and characterize lift, using dsoftware to "extract" displacement changes during mag ON state. Following an ON state, the lift rises a a fairly predictanbe rate with some minor variations as the heat plumes exit the frustum somewhat uniformly.However, am curious enough to use Schleiren photography to see this for myself. Though my test stand is temporarily disassembled, can do a static power test and shoot some video later this year...if I get some donation help. The proper mirrors and light sources are not cheap.
Disappointed to notice wallofwolfstreet has left the building here and on reddit apparently. Anyone have the details on this? I enjoyed his posts, even tho he was not a firm believer...
Quote from: rfmwguy on 10/04/2015 03:22 pmQuote from: cl33250 on 10/04/2015 06:19 amPlease don't waste time increasing airflow across the magnetron. Pressure/lift is related to velocity squared, and the fans blowing any air around the magnetron will create chaotic air currents with orders of magnitude more force than relatively slow thermal air currents.I would agree the horizontal fans may increase the chimney effect and create unwanted horizontal oscillations. Thermal plumes can only be controlled by ambient air temp equaling device temp...or vacuum testing.This thought experiment has kept me up at nights...finally thought it best to not add anything and characterize lift, using dsoftware to "extract" displacement changes during mag ON state. Following an ON state, the lift rises a a fairly predictanbe rate with some minor variations as the heat plumes exit the frustum somewhat uniformly.However, am curious enough to use Schleiren photography to see this for myself. Though my test stand is temporarily disassembled, can do a static power test and shoot some video later this year...if I get some donation help. The proper mirrors and light sources are not cheap.I've been thinking about this quite a bit as well. I agree that the use of active (fan) cooling is likely to introduce very chaotic flow and -at the level of signal we are looking for here - more noise than they eliminate. Vacuum is one way of course - likely the best and as is typically for the best - the most expensive route. One of the reasons I am strongly considering a rotary stage setup for my DIY configuration is that then the force vector being measured will be perpendicular to thermal effects (if designed carefully). Another approach which we touched on a few pages back was the second cavity arranged in such a way as to cancel (or nearly so ) thermal effects while adding "emdrive" effects. While I was advocating the need for making the cavities as near identical as possible - in reality I was wrong and as was pointed out that really isn't necessary - just getting "close" will improve the S/N. Just random thoughts on a Sunday afternoon.
NSF-1701 Paper Update. With thanks to many, I am releasing my paper a day early. I look forward to your commentary.All the best,Dave
Quote from: rfmwguy on 10/04/2015 04:10 pmDisappointed to notice wallofwolfstreet has left the building here and on reddit apparently. Anyone have the details on this? I enjoyed his posts, even tho he was not a firm believer...I have also been noticing a drop in post count here and reddit too - particularly from some of the more prolific contributors. If I were a conspiracy oriented person - which I am not - I would wonder if it has anything to do with the recent reports with more and better quality data saying SOMETHING is happening that needs looked at. Surely if the data were unequivocally indicating "nothing to see here, move along, we've all been wasting our time" some previous purveyors of preserving the status quo would be shouting that from the rooftops but instead I find myself hearing crickets from them. But likewise some of those who were either supportive of the concept or at least supportive of impartially investigation and welcoming of data of all sorts seemed to have dropped of in volume and scope of their posts, not everyone by any means - but some real luminaries none the less.If it were August I would suspect that lots of folks were just taking a late summer vacation or if September I would suspect many are just getting down to the new semester at their institutions. If this was a Hollywood conspiracy theory movie I would be suspecting the hero was going to find these missing voices were part of a vast group of commercial/government/academic investigators who had found something really significant and had been told to be quiet. And of course he/she would have to expose them and the secret and get the girl/boy and live happy ever after (perhaps on Pluto heh heh). But of course that's just crazy talk - so I suspect they have all been off waiting in line to see "The Martian" in 3D. (planning to myself RSN). Just some weirder thoughts on a Sunday afternoon - after an adult beverage or two.Herman