Since the air is not significantly contained, the pressure will equalise very rapidly, i.e. air will move about rapidly, so no significant thrust from air after power off would be expected. Instead, after power off, one would expect cooling, and a sucking back of air, resulting in a smaller force of the opposite magnitude. I expect that the air being expelled during the powered phase will be proportional to the rate of change of temperature, i.e. it would fall asymtotically as the chamber heats to steady state. This can be modelled. Assuming chamber is mostly sealed except for large vent holes in side. with holes top and bottom one might get constant convection through the device, like a pulse jet.
Quote from: TheTraveller on 05/18/2015 06:28 pmQuote from: deltaMass on 05/18/2015 06:20 pmThe characteristics of the heated air will depend significantly on its humidity too.Crank up the volume on the video, You can hear when the magnetron start to buzz and thrust appears immediately there after. When buzz stops, thrust stops. No delay.Both of you could be correct. Although, I have to side with TheTraveller on this one. It would have to be a pretty drastic, and immediate change in temperature which would not have likely happened.
Quote from: deltaMass on 05/18/2015 06:20 pmThe characteristics of the heated air will depend significantly on its humidity too.Crank up the volume on the video, You can hear when the magnetron start to buzz and thrust appears immediately there after. When buzz stops, thrust stops. No delay.
The characteristics of the heated air will depend significantly on its humidity too.
No, it's me The air/water within the chamber will average to a higher temperature.The ambient will stay ...ambient .This isn't about buoyancy. It's about a simple change in the mass of air/water vapour within the cavity.If this model is correct in accounting for the measured weight change, then we should see the same negative weight change when the cavity is flipped upside down.
When he makes a weight measurement, he is weighing the device plus whatever air/water vapour is inside it. Therefore when there is less air inside the device, the device will weigh less. It's as simple as that. Why should a higher temperature result in less air inside the device? - that's because the density of air depends on its temperature; it decreases with higher temperature. Since the device volume is constant and the density of air has dropped, there must be less air mass inside the device at higher temperature.mass = density * volume.And this is no "tiny artifact" - it's an effect on order negative half a gram, which turns out to be exactly what was measured.
Quote from: deltaMass on 05/18/2015 07:52 pmWhen he makes a weight measurement, he is weighing the device plus whatever air/water vapour is inside it. Therefore when there is less air inside the device, the device will weigh less. It's as simple as that. Why should a higher temperature result in less air inside the device? - that's because the density of air depends on its temperature; it decreases with higher temperature. Since the device volume is constant and the density of air has dropped, there must be less air mass inside the device at higher temperature.mass = density * volume.And this is no "tiny artifact" - it's an effect on order negative half a gram, which turns out to be exactly what was measured.If that was the case I would like you to consider that the air takes time to evacuate the chamber and internally heat the air. The scales would slowly increase instead the decrease like we see. This seem right?
@TheTraveller:What are the units and semantics of your vertical scale?
So your thrust is in opposite direction from EagleWorks, right?
Quote from: txdrive on 05/18/2015 08:27 pmSo your thrust is in opposite direction from EagleWorks, right?Movement is as per Shawyer. From the big end toward the small end.Watch the video to see which way it moves.http://emdrive.com/dynamictests.html
Quote from: TheTraveller on 05/18/2015 08:30 pmQuote from: txdrive on 05/18/2015 08:27 pmSo your thrust is in opposite direction from EagleWorks, right?Movement is as per Shawyer. From the big end toward the small end.Watch the video to see which way it moves.http://emdrive.com/dynamictests.htmlAs per Shawyer's theory papers, it should be moving wide end forward.
Quote from: txdrive on 05/18/2015 08:41 pmQuote from: TheTraveller on 05/18/2015 08:30 pmQuote from: txdrive on 05/18/2015 08:27 pmSo your thrust is in opposite direction from EagleWorks, right?Movement is as per Shawyer. From the big end toward the small end.Watch the video to see which way it moves.http://emdrive.com/dynamictests.htmlAs per Shawyer's theory papers, it should be moving wide end forward.Reaction / EM Drive physical movement is in the opposite direction to Thrust direction. He has stated this many times.
The group velocity of the electromagnetic wave at the end plate of the largersection is higher than the group velocity at the end plate of the smaller section. Thusthe radiation pressure at the larger end plate is higher that that at the smaller end plate.The resulting force difference (F g1 -F g2 ) is multiplied by the Q of the resonantassembly.
Quote from: TheTraveller on 05/18/2015 08:43 pmQuote from: txdrive on 05/18/2015 08:41 pmQuote from: TheTraveller on 05/18/2015 08:30 pmQuote from: txdrive on 05/18/2015 08:27 pmSo your thrust is in opposite direction from EagleWorks, right?Movement is as per Shawyer. From the big end toward the small end.Watch the video to see which way it moves.http://emdrive.com/dynamictests.htmlAs per Shawyer's theory papers, it should be moving wide end forward.Reaction / EM Drive physical movement is in the opposite direction to Thrust direction. He has stated this many times.http://www.emdrive.com/theorypaper9-4.pdfQuoteThe group velocity of the electromagnetic wave at the end plate of the largersection is higher than the group velocity at the end plate of the smaller section. Thusthe radiation pressure at the larger end plate is higher that that at the smaller end plate.The resulting force difference (F g1 -F g2 ) is multiplied by the Q of the resonantassembly.So, it would have to be mounted the larger plate forward if you want your ship to go forward.
Quote from: TheTraveller on 05/18/2015 08:43 pmQuote from: txdrive on 05/18/2015 08:41 pmQuote from: TheTraveller on 05/18/2015 08:30 pmQuote from: txdrive on 05/18/2015 08:27 pmSo your thrust is in opposite direction from EagleWorks, right?Movement is as per Shawyer. From the big end toward the small end.Watch the video to see which way it moves.http://emdrive.com/dynamictests.htmlAs per Shawyer's theory papers, it should be moving wide end forward.Reaction / EM Drive physical movement is in the opposite direction to Thrust direction. He has stated this many times.http://www.emdrive.com/theorypaper9-4.pdfQuoteThe group velocity of the electromagnetic wave at the end plate of the largersection is higher than the group velocity at the end plate of the smaller section. Thusthe radiation pressure at the larger end plate is higher that that at the smaller end plate.The resulting force difference (F g1 -F g2 ) is multiplied by the Q of the resonantassembly.So, it would have to be mounted the larger plate forward if you want your ship to go forward. According to his "theory" anyway. No idea where his experiments are going, my guess is which ever ways vibration and shifts in the centre of mass take them.