Dear David. If there a way in your simulation to prove that the nickel particles would all be melted unless some LENR miracle is preventing it.
See my tread Super​-fluidic heat flow for tomclarks analysis. On Tue, Oct 14, 2014 at 11:24 AM, David Roberson <[email protected]> wrote: > That seems to be the best explanation that is derived from my model. > Stable operation of the HotCat is achieved when the heat generated by the > core finds an easy escape from the device. Since it is highly likely that > the heat energy generated within the core increases at a rate that is > greater than linear and zero at low temperatures, it becomes necessary to > remove the increasing heat that is generated as the core temperature > rises. The radiation that occurs, which is proportional to the forth power > of the temperature, takes care of the very high temperature region of > operation. > > The simulation model initially latched at an intermediate temperature due > to too much positive feedback in that operating range and the addition of a > more robust method of extracting energy solved that issue. In this case a > better sink turned out to be a more efficient convection or conduction term > that is associated with a lower polynomial power. The geometry > modification appears to be the best way to increase the convection and > conduction terms to achieve the required stability. > > I have more to come with regard to my model and how it indicates that > internal heat generation is a near certainty. This can be understood in > light of the device behavior described within the latest report. > > > Dave > > > > -----Original Message----- > From: Alain Sepeda <[email protected]> > To: Vortex List <[email protected]> > Sent: Tue, Oct 14, 2014 2:29 am > Subject: Re: [Vo]:Interesting Simulation Results > > you explain the new shape of the reactor covering, with the > <||> > <||> > <||> > shapes, as a required increase of convection ? > > > what I see in that reactor is dozens of engineering innovations, not so > sexy as LENR, but the kind engineer do everyday to make rocket fly. > > 2014-10-13 23:21 GMT+02:00 David Roberson <[email protected]>: > >> I decided to review my ECAT simulation model to see if it were reasonable >> to achieve a COP of around 3.5 while operating within a non thermal runaway >> region under steady state conditions. The earlier runs and model tended to >> indicate that it is quite precarious to operate the ECAT at a COP of >> greater than 2 without the pulse wide modulation input power waveform. >> >> Once a decision is made to operate within a potentially unstable region, >> it becomes necessary to turn the input power on and off periodically to >> prevent thermal run away. To the best of my knowledge, Rossi has used this >> type of operation until the latest test. In that demonstration the input >> drive is relatively constant and operation in the so called SSM mode not >> used. >> >> The new HotCat expels the internal heat through a combination of >> radiated, convected and conducted paths. The radiation path is quite >> useful when one attempts to prevent thermal run away conditions since a >> small increase in surface temperature results in a large increase in >> thermal radiation. Everyone by now has seen that the radiation goes up >> proportional to the forth power of the temperature and that puts the brakes >> upon increases in extra power generation due to internal temperature >> increases. >> >> My main question was related to understanding how he now can operate >> without having to worry so much about overheating and thermal run away >> while that was such a problem before. The trick apparently is in the >> geometry of the device. A large surface area is available to radiate away >> the escaping heat at a manageable surface temperature. Also, the surface >> of the main cylinder is specially treated with grooves to enhance thermal >> escape due to convection. >> >> This carefully constructed design is capable of removing enough heat to >> quench the positive feedback action that the internal core would normally >> encounter at the elevated operating temperatures. My model needed to take >> into account the new geometry features that were not present in the earlier >> devices. >> >> When I first ran a simulation of the new device I noticed that it was >> easy to limit the maximum temperature since the radiation was so efficient >> at handling the extra internal heat energy generated by any moderate >> increase in core temperature. I model the core heat generation by means of >> a polynomial power series and as long as the main terms contributing to the >> core heating are below forth order, a stable operating point is obtained. >> It would be useful to have the actual power series from an operating >> device, but that is apparently too much to expect at this time. >> >> A problem appeared when the input power was removed. As expected the >> temperature dropped a large amount in the core, but it reached a point of >> stable continuous output. This situation would not be tolerable and >> fortunately not seen within the test. I scratched my head and then >> realized that a cure to the problem was available. I adjusted the >> coefficient of the linear term that represented the convection heat >> emission and found that a value could be chosen that allowed the output >> temperature to continue downwards when input drive is removed. This >> adjustment very much falls into line with the real device since a lot of >> effort was expended in designing the groove structure. >> >> When the dust settled I had an opportunity to figure out exactly what was >> required to achieve a stable system. The surface area of the device must >> be designed so that convection currents carry away more heat than is >> generated within the lower temperature regions. This is needed to ensure >> that a low temperature latching performance is not obtained. Also, the >> surface areas must be able to radiate the correct amount of heat at the >> desired operation point. In that case, the sum of the drive power and the >> internally generated core power has to match the power that is emitted due >> to radiation, convection and conduction. >> >> This new model is amazingly simple in structure but demonstrates >> interesting insight into operation of the new CAT. Operation with a COP of >> approximately 3.5 did not seem to be too difficult with the optimum >> parameters according to the latest model. I plan to continue to evaluate >> my model as time permits and new data and questions arise. >> >> Dave >> > >
