[...Thanks Dr, in my world it was thermal. Interesting to note the interference pattern was divided into quadrants and the only image I could locate to explain it was the "diffuser". Soooo, guess no one did a thermal of the DUT?
Quote from: TheTraveller on 05/18/2015 04:34 pm...Shawyer likes to drop bread crumbs, to create a trail for those interested to follow.Bread crumbs? I feel like a bird ...
...Shawyer likes to drop bread crumbs, to create a trail for those interested to follow.
Quote from: TheTraveller on 05/18/2015 04:16 pmInteresting version of the C band Flight Thruster and dimensions.www.slideshare.net/Stellvia/emdrive-presentation-at-space-08-conference-barbican-london-presentationNever seen this before Not a truncated cone.What happened to the spherical waves? Is there an explanation to its flat sides and the departure from the conical shape ?
Interesting version of the C band Flight Thruster and dimensions.www.slideshare.net/Stellvia/emdrive-presentation-at-space-08-conference-barbican-london-presentation
The expectation for measured weight change for Iulian's device is about -0.5 gm-weight (becoming lighter), assuming a temperature rise of the air within the device of about 25oC, and assuming the device volume to be about 6 litres. The mechanism here is based simply on the change in weight of the air within the device. Because the device is not sealed, air can move in and out of it as its temperature changes. The larger the device volume, the larger the expected measured weight change.I've now calculated the volume to be ~37 litres, and so we need roughly only 1/6th of the previously calculated temperature rise to get the observed weight change - just a few degrees will do it.
The expectation for measured weight change for Iulian's device is about -0.5 gm-weight (becoming lighter), assuming a temperature rise of the air within the device of about 25oC, and assuming the device volume to be about 6 litres. The mechanism here is based simply on the change in weight of the air within the device. Because the device is not sealed, air can move in and out of it as its temperature changes. The larger the device volume, the larger the expected measured weight change.
The characteristics of the heated air will depend significantly on its humidity too.
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.
Quote from: deltaMass on 05/18/2015 05:54 pmThe expectation for measured weight change for Iulian's device is about -0.5 gm-weight (becoming lighter), assuming a temperature rise of the air within the device of about 25oC, and assuming the device volume to be about 6 litres. The mechanism here is based simply on the change in weight of the air within the device. Because the device is not sealed, air can move in and out of it as its temperature changes. The larger the device volume, the larger the expected measured weight change.I've now calculated the volume to be ~37 litres, and so we need roughly only 1/6th of the previously calculated temperature rise to get the observed weight change - just a few degrees will do it.How on Earth did you come up with such a large volume? 37 litres is a cubic volume ~33.3 cm on a side. Even 6 litres is a cubic volume 18.17 cm on a side which is quite large. Do we know the dimensions of the device?
Not so sure about that. Air is driven out by the pressure differential. As soon as the magnetron is switched off, the driver for that pressure difference vanishes and colder air rushes back in.
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.I'd also like to point out that the thrust drops off the more it's run. If air were a significant contributor to the readings, you'd expect to see it go up (or rather, down) the more the device is run, no?
Quote from: Dortex on 05/18/2015 06:58 pmQuote 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.I'd also like to point out that the thrust drops off the more it's run. If air were a significant contributor to the readings, you'd expect to see it go up (or rather, down) the more the device is run, no?No, I think. Repeated runs occurring close in time to one another will tend to push up the average temperature. Therefore the change in temperature of the water vapour in the air, and of the air itself, will be that much less after several consecutive runs.