Axil, the only details that I have are the ones that have been published on Rossi's Journal and other public information. My model is based upon some assumptions that I will attempt to explain. I would like very much for you or others to contribute to the simulation if possible.
The first question I can only answer from results of my model which match Rossi's discussions. He states that the drive power is applied at a 50% duty cycle and its level is one third of the total output power. If you take his recent typical output power of 10 kW, that means that it has a drive waveform of 3333.33 watts with a duty cycle of 50%. So, it typically takes that much power input drop to reverse the rising temperature waveform. My model agrees with this number. The model suggests that the device has an unstable point at a bit more than half of this level of output and that positive feedback is causing most of the rise in power output until the reversal. Once heading downward, the temperature curve and associated power output continue until again driven by the 3333.33 watt waveform. The reason for this behavior was murky at first since I did not understand why a relatively low drive power would reverse the process. Further simulations pointed to the thermal capacity of the device as the reason. The loss of this amount of drive starved the heat being absorbed by the thermal capacity of the unit just enough to force the rising curve to reverse. This was a very interesting result. The device response timing is unknown in detail unless we can shake it out of Rossi. It must be fast enough to outrun the rising temperature waveform that wants to supply the thermal capacity. I used a convenient value of thermal capacity to allow time for the waveforms to be visible in my simulator. There is some really interesting phenomena hidden within this model. Your question about heat loss causing problems is related to the thermal impedance of the device to ambient. Once a value has been realized, there will be a slope of power output versus temperature where the product of the two functions is 1. The temperature associated with this point is where the positive feedback takes over. This is the traditional point where the loop gain is 1. I have some model details to follow soon. Dave -----Original Message----- From: Axil Axil <[email protected]> To: vortex-l <[email protected]> Sent: Thu, Aug 30, 2012 3:37 pm Subject: Re: [Vo]:ECAT Simulations With Third Order Temperature Dependency Great stuff Dave. On the face of it, this Rossi reaction control mechanismseems primitive and problematic. Do you have additional details? When the reaction is operating at 1200C, what level oftemperature spike is required to reverse a dropping reaction temperatureprofile? Does the maximum level of external temperature spike ever get above1450C at any point? How long does thereaction take to respond to the temperature spike? What causes the reactiontemperature to fall? How long does the reaction take to regain stability? How much power does the external temperature impulseconsume in a 10 KW system? How much heat loss from pore insolation can thereactor tolerate? Cheers: Axil On Thu, Aug 30, 2012 at 1:50 PM, David Roberson <[email protected]> wrote: I performed additional analysis and have a couple of items to add to the simulation results. The first one is that it is obvious that the Rossi controlled devices operate within the thermal run away region to achieve a COP of 6. In these cases, the positive feedback is responsible for the gain and also set the time constants required to keep the units stable with drive. Other implicit components that effect the time constant are the thermal capacitance of the core and thermal resistance through which the heat energy flows. One consequence of operation within the unstable region is that a strong shock is required to force the rising temperature function of the device to reverse direction. Once reversed, the temperature will head toward zero and stable operation unless another external positive heating shock occurs at an important time. This behavior might well explain why Rossi continues to insist that he can not use the heat output of an ECAT to drive additional ones. The slow response time of the ECAT driver would not constitute a thermal shock that could control the operation of its brothers. An electric or gas heater can respond rapidly enough to achieve the desired results. Perhaps I sound like a Rossi fan by continuing to support his claims while many of the other vorts seem to question them. I guess my confidence in many of his statements is that they tend to be confirmable by my model performance. If he were totally full of "***" then why insist upon a COP that is reasonable, but low, when claiming a higher value would be advantageous? How would extending this claim make him more of a dud? Dave -----Original Message----- From: David Roberson <[email protected]> To: vortex-l <[email protected]> Sent: Wed, Aug 29, 2012 4:50 pm Subject: [Vo]:ECAT Simulations With Third Order Temperature Dependency Earlier I posted information obtained by simulating the ECAT device. The last version assumed that the ECAT internal LENR energy generation mechanism depended upon the core temperature as a second order function. The latest trial runs were obtained by using a model that allowed this temperature dependency to be of the third power. I was curious as to how much more critical the system would behave at this higher power and gave it a test run. I was able to obtain a COP of almost 18 if I pushed the operation of the core to the brink of critical run away temperature. This would not be acceptable unless an active cooling method was also available that could extract heat rapidly from the core if its temperature became too great. Rossi may have something of this nature in his latest design, but it is not evident. The power drive duty cycle was required to be approxiamtely 10% during this test run. If I operated the device within a conservative mode where I kept the temperature at 90% of the run away value I only obtained a COP of 3.61. I noted that the duty cycle of the drive was 50% which is as Rossi has stated within his journal. With these two independent runs available for reference it is clear that I could obtain the expected COP of 6 if I carefully chose the peak temperature excursion of the device. In the earlier experiment with the temperature dependency of second order the matching seemed to be easier and I achieved a good level with the first attempt. The implication of my modeling is that it is likely that Rossi or anyone who has a device that follows this general rule would be capable of making the COP of 6.0 if the design contains a reasonable geometry and has the internal thermal resistances properly adjusted. If anyone is aware of the power output-temperature functional relationship of Rossi's device please direct me to that data so that I can adjust the model to match the real world more closely. At this point it appears that Rossi is playing conservative and safe with his claimed COP of 6. He may eventually raise this level to be more competitive with others and there is room for adjustment especially if a good technique is used to actively cool the core. The usual disclaimer applies to this document. The model is for educational purposes only and may not reflect upon real device operational characteristics. Dave P.S. Contact me directly if you want further details about the model or its behavior.
