...I'm assuming this was tested with internal vacuum. Or was it just frozen air that was vaporized by RF energy?
the POC cavity and attached vacuum tubing are only supported by the central vacuum pipe depicted in Figure 4. The central vacuum pipe is attached to a support arm depicted in Figure 4. During experimental runs, the cavity and attached vacuum tubes are supported by two Cooper Instruments LFS 210 load cells. ....the helium dewar depicted in Figure 4 is vacuum sealed. Pressure over the liquid helium is reduced to 50 Torre reducing its temperature to 2.3 K. Prior to experimental runs, the vacuum seal on the helium vessel is broken, bringing pressure above the liquid helium to atmospheric pressure. Tests on the cavity were then run while the liquid helium bath was below its atmospheric boiling temperature. The helium pump-down procedure eliminated boiling helium buoyancy beneath the cavity as a potential cause of false-positive experimental results.
Quote from: ThinkerX on 10/28/2014 01:25 amI am starting to wonder if the info needed the most (predictive equations, measurements, frequencies) isn't hidden away by Non Disclosure Agreements. Might account for the lack of later papers (after 2007) by Doctor White, and why getting other info is like pulling teeth.There just doesn't seem to be all that much to most of these devices. A competent machinist could probably build one in a weekend from scratch for not much more than beer money. Oddly shaped and constructed microwave ovens basically. Sonny told Pop Sci when they came for a visit that he was restrained by NDA, but there are long odds on that. Who would have asked him to sign it? (Apart from the outside work they did for Boeing, wich makes perfect sense.) Rather he has likely asked others to so sign. The real issue here is that Sonny can't patent anything since he didn't invent the stuff. Best he can do is operate under trade secret status so you should not expect ever to get much detail about his setup.BTW as we mentioned before, this cannot be done with a microwave oven magnetron. It needs a continuous wave magnetron. They're much more expensive, most often water cooled and not the kind of thing you can pick up on EBay for $25. They draw several kW of power and if you mess up with one, they're fry the inside of your eyeballs in 3 seconds. So this is not as simple as it seems.
I am starting to wonder if the info needed the most (predictive equations, measurements, frequencies) isn't hidden away by Non Disclosure Agreements. Might account for the lack of later papers (after 2007) by Doctor White, and why getting other info is like pulling teeth.There just doesn't seem to be all that much to most of these devices. A competent machinist could probably build one in a weekend from scratch for not much more than beer money. Oddly shaped and constructed microwave ovens basically.
@RodalIs what you're looking for from Dr. White on page 5?http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492.pdf
Quote from: Mulletron on 10/28/2014 02:57 pm@RodalIs what you're looking for from Dr. White on page 5?http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492.pdfThanks for taking the time to look for this, but no, this report by Dr. White does not contain any explicit equation with which one can calculate a thrust force.
It looks that you are assuming that one half is a male and the other half is a female and they mate with each other...
Quote from: Rodal on 10/28/2014 12:36 amQuote from: Rodal on 10/28/2014 12:30 amQuote from: frobnicat on 10/28/2014 12:12 am...Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code. I'll be back with the correct resultYes, any tau>0.2 sec is clearly discernable.For tau ~ 1 sec the difference is unacceptableI'll post some pictures tomorrow after I double check everything. I need to do some work for which I get real $$$ first All right. I'm a bit surprised then. Maybe not 7s but 2s seemed like possible to me (with eyeballs used to look at basic second order ringing oscillators).
Quote from: Rodal on 10/28/2014 12:30 amQuote from: frobnicat on 10/28/2014 12:12 am...Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code. I'll be back with the correct resultYes, any tau>0.2 sec is clearly discernable.For tau ~ 1 sec the difference is unacceptableI'll post some pictures tomorrow after I double check everything. I need to do some work for which I get real $$$ first
Quote from: frobnicat on 10/28/2014 12:12 am...Sorry, I re-checked the code because that statement about the 7 sec didn't make sense to me and I found an error on my definition of the exponential function (I had the variable "time" instead of "t" which mean different things in my code. I'll be back with the correct result
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@ Dr. Rodel - You're Welcome.With the right choice of resonant mode frequency the standing wave within the cavity results in unbalanced axial pressure giving thrust to the cavity, via the equation from the Chinese paper. The question still arises,"Where does the momentum balance?" Conservation is still very much of interest after all.We are kind of at the point in sailing ship days where some crewman tied his sleeping roll to his oar, held it up and told his buddies, "Look, if I hold the corners with my feet I don't have to paddle!!"That was long before tall ships with area ruled hulls and sloop rigged masts.
Quote from: aero on 10/28/2014 08:49 pm@ Dr. Rodel - You're Welcome.With the right choice of resonant mode frequency the standing wave within the cavity results in unbalanced axial pressure giving thrust to the cavity, via the equation from the Chinese paper. The question still arises,"Where does the momentum balance?" Conservation is still very much of interest after all.We are kind of at the point in sailing ship days where some crewman tied his sleeping roll to his oar, held it up and told his buddies, "Look, if I hold the corners with my feet I don't have to paddle!!"That was long before tall ships with area ruled hulls and sloop rigged masts.1) None, absolutely none of the researchers have actually measured linear acceleration of the center of mass of the system under measurement. No discussion of conservation of momentum is really an issue until somebody does. The ideal test would be for a free-free body, as done by the Wright brothers, Goddard, even the Gossamer Albatros, and the recent demonstration of the man-powered helicopter (which was considered impossible until recently).2) NASA Eagleworks, the Chinese, Cannae, and Shawyer (except his demo) have made measurements on constrained systems. None of the researchers have analyzed their measurement systems to analyze whether indeed conservation of momentum is being violated. The closest experiment to a violation of conservation of momentum is Shawyer's demo experiment, but again, the EM Drive demo is restrained and the whole setup is rotating instead of linearly accelerating. No linear acceleration of the center of mass was measured and the measurement system was not analyzed.If an astronaut inside a spacecraft puts a sensor on a wall of a spacecraft and then takes a big hammer and hits the wall of the spacecraft, he will measure dynamic motion of the wall of the spacecraft. That doesn't mean that conservation of momentum was violated. In that experiment the center of mass of the whole system (astronaut, hammer and walls) did not experience any acceleration due to the astronauts hammering the wall. However, the wall did move and it had a noticeable dynamic response.Discussions of violation of conservation of momentum are premature until an experimenter shows that the center of mass of the whole system experienced an acceleration response either by flying the object unrestrained (free-free) or they properly analyze the measurement system - which nobody has done.
Shawyer made an explanation years ago about how the thruster would develop less and less thrust the faster it was going, but the mechanism made no sense, and it still proposed to violate conservation, and the whole notion of velocity changing thrust is again, a violation of relativity. Velocity relative to what exactly? ...snip...
There is no explicit mating shown in the referenced picture (reproduced below), and again you are considering the lip from only one side.
Quote from: Rodal on 10/28/2014 04:20 pmThere is no explicit mating shown in the referenced picture (reproduced below), and again you are considering the lip from only one side.Not quite sure I unnerstand ya, doc. Here's my guess as to what the section thru the completely fabricated round thing is.