Okay I'm going to use E field drive and sense probes (instead of loops) within the cavity placed at 1.36" from the large plate. It seems to me that the connector should be at the small end. I'm kind of torn on this. It probably doesn't matter. Shawyer/Eagleworks have the connectors at the large end, so I will too.There is a nifty calculator here to make it easy:http://www.turnpoint.net/wireless/cantennahowto.htmlhttp://www.lincomatic.com/wireless/homebrewant.html (more info)Also some backgrounders for those who are interested: http://www.radartutorial.eu/03.linetheory/tl11.en.htmlhttp://www.maritime.org/doc/neets/mod11.pdfThis is also in agreement with the 15% of 9" cavity height from the large end which came out to 1.35", brought up here: http://forum.nasaspaceflight.com/index.php?topic=36313.msg1331854#msg1331854The length of the probe will be 1.21" or 31mm, based on a 1/4 wavelength of the desired frequency 2450mhz.The type of connector will be an N-type female in the top picture, as opposed the one in the bottom picture. That way I only have to drill one hole instead of five per connector. The size of the center hole required for both is within 1/16" so I'm not going to bother with the 4 hole bulkhead connectors I got. I wanted to see them both before I decided on which one to use.The connectors were purchased from here, I guess they sold out because they now say unavailable:http://www.amazon.com/gp/product/B00OOF54QW/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1http://www.amazon.com/gp/product/B006Z95L8Q/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1I'm sure there are more on Amazon, but if not, I've purchased from these guys before and had a good experience:http://www.fab-corp.com/home.php?cat=274

Rodal I need your expertise On the magnetic field maps given by Eagleworks simulations and from your exact solutions, is it correct to interpret that the heating power per unit area of frustum inner wall will depend locally as the square of the magnetic field magnitude ? Is the scalar intensity value map below enough to get the heating rate at each point or is the vector map required ? Will we have a smooth transition (in heating rate per unit area) between the PCB plate and cone in spite of the angle they make at the rim ?Trying to get a more accurate view on displacements : the PCB plate can buckle by thermal expansion against a rigid rim, but the rim is itself heating and expanding, will try an axisymmetric simulation taking both into account + thermal gradient (across thickness) induced "warp".

Quote from: frobnicat on 03/15/2015 01:00 amRodal I need your expertise ...1) Paul March kindly supplied both the COMSOL Finite Element dissipated heat (W/m^2) per unit area (the finite element model takes into account geometrical changes like the "angle" you are concerned with) as well as the NASA Eagleworks thermal IR camera measurements:...so you don't need to rely solely on the magnetic field

Rodal I need your expertise ...

2) Assuming an adiabatic process, the volumetric power dissipation P_{dissipated} in the material due to the applied magnetic field should be: P_{dissipated} = Pi*f*Chi"*(B^2)/(mu*mur) = Pi*f*Chi"*(H^2)*muof=frequency (Hz)Chi"= out-of-phase susceptibility (complex component of the susceptibility) of the materialmur = relative permeability of the materialB = magnitude of induction = permeability * HH = magnitude of magnetic field strengthSo yes, assuming an adiabatic process, the volumetric power dissipation goes like the square of the magnitude of the magnetic field.3) The magnitude of the total vector resultant matters (one needs to take into account the resultant of the vector components, which has been done in the plot supplied by Paul March). The direction doesn't matter.

4) Questions like "Will we have a smooth transition (in heating rate per unit area) between the PCB plate and cone in spite of the angle they make at the rim ?" and other statements in this and the other posts I can't follow without seeing the unstated equations, assumptions and values, you use for your models. For example, I don't understand why you are concerned by "a smooth transition" due to the geometrical angle when we have discontinuous material properties between the epoxy and the copper)

....For the rest I don't see how I could make the statements more clear (more synthetic yes probably)...

Yes, this is a very informative instantaneous map of temperature, but I wanted to reconstruct the dynamic (transients) and also have the gradients through thickness.....

....Why I wanted to start again from the primary heat flux dissipated within the skin depth copper side, even if it is with far lower numerical tools than provided by Comsol results. I wish Eagleworks had added a deformation study from the very accurate thermal maps.

... I'm still struggling to assert, especially if the PCB as even a very modest inward warp to start with (which is a concern for single sided boards) like a few 10s of microns at belly....

Quote from: frobnicat on 03/15/2015 05:42 pm....For the rest I don't see how I could make the statements more clear (more synthetic yes probably)...Speaking personally, it would be clearer if you would state the equations that you are using for your posted calculations, defining the variables in the equations, and the values of the parameters you used to arrive at a solution. (e.g. what were the material property inputs you used and the equations you used for the personal code thermal calculations?)

The fact is that Paul March gave us the calculated dissipated power W/m^2 vs. location. In your prior post you referred to Paul's data for the calculated magnetic field, and in this post you acknowledge the measured temperature. Quote from: frobnicat on 03/15/2015 01:00 am....Why I wanted to start again from the primary heat flux dissipated within the skin depth copper side, even if it is with far lower numerical tools than provided by Comsol results. I wish Eagleworks had added a deformation study from the very accurate thermal maps.To be precise, Eagleworks did not provide COMSOL calculations (to my knowledge) of a thermal map (temperature vs. location). What Eagleworks provided are (COMSOL Finite Element) calculations for the dissipated power per unit area (in units of power per surface area: Watt/m^2) surface losses throughout the whole 3-Dimensional surface (both the large and small diameter ends as well as the lateral round conical surface). And it is the volumetric power dissipation that goes like the square of the magnitude of the magnetic field, which was your question. So, Paul March had already given you the elements to answer your question: both the magnetic field and the power dissipation density.The thermal map is a result of IR thermal measurements.

Quote from: frobnicat on 03/15/2015 05:42 pm... I'm still struggling to assert, especially if the PCB as even a very modest inward warp to start with (which is a concern for single sided boards) like a few 10s of microns at belly....Since the bending deformation of the end plate (due to a thermal gradient through its thickness, referred to as "oil canning" in the picture below) is inwards, and you had arrived at the conclusion that such an inward deformation produces a force that is in the opposite direction to the measured force , why are you so interested in performing this calculation?

If your purpose is to show that the actual EM Drive force (due to the Quantum Vacuum or whatever else may make it work in space?) is larger than the measured force, then I lost track of the discussion somewhere because I recall you stating that you wanted to show the opposite: that the measured force was an artifact.?

....For the later results (thermal conduction), I'm not expecting anyone give too much credit in the accuracy of a personal simulation code,....FR4density 1850 kg/m^3specHeat 600 J/kg/K...

Quote from: frobnicat on 03/15/2015 08:36 pm....For the later results (thermal conduction), I'm not expecting anyone give too much credit in the accuracy of a personal simulation code,....FR4density 1850 kg/m^3specHeat 600 J/kg/K...It is not a question of giving personal credit, but my understanding of your posting such calculations is to check whether the experimental results are an artifact or whether they are due to a real thrust that can work for outer space propulsion. If you don't post the equations and the material properties you use, then how can the reader ascertain how to evaluate what you post?To give one example, we see now that you used a value of 600 J/kg/K for the specific heat of FR-4 (no reference as to where this came from). However, Rebecka Domeij B¨ackryd at LINK¨OPING University (Sweden) used a value twice as high: 1200 J/kg/K (see page 14 of http://www.diva-portal.org/smash/get/diva2:18631/FULLTEXT01.pdf )

....You complain that my hypothesis and variables and equations are not clearly put, but do you read me seriously ?...

A movement to the left of a part of mass M will make a force to the right as recoil : F(t)=-M d˛CoMPosition(t)/dt˛. " OK, so the force is to the right and it is opposite to the measured force ..."Such F(t) is small, very small, even by µN standards. It depends on the second derivative of the shift (wrt time).

Now, if we have the right to go past those negligible recoil effects :... A slow inward deformation don't produces a force (ah ah, it does, but is too small to be significant). I'm no longer talking of force. I'm talking change of rest equilibrium position (by rest equilibrium I mean : the stable position when there is no force)

Quote from: frobnicat on 03/15/2015 09:35 pm....You complain that my hypothesis and variables and equations are not clearly put, but do you read me seriously ?...I just stated that I personally have a hard time following your train of thought, and that I personally would prefer to see more equations. You could justifiably answer that it is my fault because of my lack of reading comprehension. I don't recall me stating that it was your fault, I actually recognized that it is probably my fault because in physics and technical science I can much better understand equations than words.

....I wanted to show that the measured "force" (LDS reading really) might not be a force at all, but a change in equilibrium rest position, as per the diagram showing how the equilibrium rest position is different depending on test article CoM position...