Plot 8, page 27

Plot 3, page 25

Average ~ 300 C

Pk-to-pk amplitude ~ 25 C

Levi data

Average ~ 810 W

Pk-to-pk amplitude ~ 110 W

ton=153 s

toff=287 s

The main data shown in the Levi report, http://arxiv.org/ftp/arxiv/papers/1305/1305.3913.pdf , are the

following two graphs

Noting the shapes of the curves, and the average and pk-to-pk values, a simulation will be presented to see what is

needed to reproduce these figures.

First will be needed the ‘reactor’ physical dimensions, see the following few slides.

Wiring

Parallel short

Parallel short

HeaterHeater

Thermocouple

Heater #1

terminals

Heater #2

terminals

It seems that there are two heaters (similar to the Penon report,

http://www.mediafire.com/download/l4vfaky8v9bx90d/105322688-Penon4-1.pdf ), which are connected in

parallel and driven by one set of power cables (yellow/green).

There appears to be no other wiring attached to the HT2

Yellow heater power cables

White thermocouple cable

Wiring

20 cm

(from report)9.7 cm 7.9 cm 6.4 cm, resistive heater elements

Dimensions

From the Levi report, the flange diameter is 20 cm. By scaling the other distances to the flange diameter, the

above measurements were made.

The heater connections (and hence presumably the heater elements) seem to be at a radius of 32 mm.

Dimensions

20 cm

9.5 cm

7.9 cm

1.5 cm, thermocouple offset from centre

By doing the same measurements in the horizontal direction, we find about the same values, plus we find that the

thermocouple is placed at a radius of 1.5 cm, which corresponds to the outer edge of the 3 cm diameter insert tube.

Dimensions

20 cm

from report 9.0 cm

Assuming again that the flange is 20 cm, one measures the HT2 diameter to be 9.0 cm, which agrees

with the reported diameter

Gauge of wires

While it is hard to tell accurately the outer wire diameter, choosing various places to measure (and using

the same scale as set up in the previous diagrams), I estimate the insulation outer diameter to be about 5

mm.

The thermocouple wire seems very thick, possibly to cope with the temperatures involved.

Compare to this electric cable with 4.5 mm outer diameter, which can carry up to 41*450 = 18 kW electrical

power.

http://radionics.rs-online.com/web/p/mains-power-cable/0536136/

Given that the Penon report quoted two heating resistors with 12 ohms in parallel, and the Levi configuration

seems to be similar, such cables should be able to support P = I2.R = 412.6 = 10 kW of heating power to the eCat,

well above the quoted values of around 1 kW, and above the implied generated power of 6 kW (COP=6).

Power capacity of wires

Simulation geometry

Now that we have some idea of dimensions, we need to assign three material constants for each layer:

Density kg/m3, thermal conductivity W/(m.k) and thermal capacity J/(kg.K)

The mass of each layer is calculated from m = 2.π.r.L.dr.ρ

where r is the radius of the layer, L is the cylinder length, dr is the layer thickness and ρ the density.

In this model, the outer diameter is set at 9.0 cm, the innermost one (internal to the 3 cm removable tube) to be 1.3 cm

and the layer thicknesses are 1 mm. Cylinder length L is 33 cm. Cylinder ends are neglected.

Implementation of the model is outlined in http://www.slideshare.net/brslides/rossi-hotcat-penon-report-simulation

drr

Material profile

Here are the three plots for the material constants used, as a

function of radius. The different materials are assumed to

have perfect contact with each other, but that assumption

will be questioned later.

The first 1.5 cm, up to the green vertical line, represents the

‘core’ tube, with any assumed Ni/H reaction at the

innermost edge of about 0.7 cm.

The remaining 1.5 to 4.5 cm represents the ‘bulk’ reactor,

consisting of two steel tubes and a resistor block.

The positions of the thermocouple (green line at 1.5 cm) and

resistive heaters (red line at 3.2 cm) are shown for

reference.

Inner reactor

insert

thermocouple

position

inner wall of

main reactor

outer wall of

main reactor

resistor

block

resistor

positionLENR

layer

outer

radiating

surface

Assume good conduction, and LENR is on all the time, Temperature plots

From an analysis of the Penon report, discussed here, http://www.slideshare.net/brslides/rossi-hotcat-penon-report-

simulationone can estimate the power that the LENR reaction must have been, assuming that all the measurements

were accurate at face value. By using that data, assuming consistency between the Penon and Levi tests, one can plot

the temperature of the four layers shown as above.

Note that the surface temperature has about 15 C pk-pk variation (Levi’s was 25 C), and is much sharper than Levi’s

data.

Other parameters related to the sim are

scalef=1.15; % scaling factor in comparison to Penon report. Can be non-unity due to different powder volumes.

COP=2.9; % Coefficient of performance

Pelec=810; % W peak, duty cycle=35%

outer surface temperature

resistive heater layer

thermocouple layer

LENR layer

Assume good conduction, and LENR is on all the time, Power plots

These results are from the same conditions as in the

previous slide, but showing the electrical input power in

red, and the total output power in black.

Pk-pk variation of 80 W (Levi’s was 110 W).

This plot shows the contribution of the simulated LENR

component of the output power, in magenta. There is

some variation in LENR power, as the inner core

temperature increases and decreases slightly due to the

electrical pulsing, but this variation does not contribute

much to the observed external variation.

contributed

LENR excess

power

radiation

and

convection

output

power

One notes that the output power has much ‘sharper’ corners than the plot shown in the

Levi report. Hence the scenario simulated here (that the LENR reaction is always present)

does not seem a good match to the data.

LENR only during on phase

Changing the LENR behaviour so that it is only on when the

electrical pulse is on (possibly because the ‘trade-secret

waveforms’ are only on then (?)), one gets this set of figures.

Temperature variation is 30 C, power variation is 150 W, and

the shapes match Levi’s data quite well. Considering the

unknowns in the material construction of the Hot-Cat, this

result seems consistent with the data.

How likely it is that an internal reaction will only be on during

the pulse is unknown.

Sim properties are

scalef=3.1; % 3.1 times the Penon report seems rather high?

COP=2.9;

Pelec=810; % W peak, duty cycle=35%

contributed

LENR excess

power. Only

on during the

pulse.

output

powersurface

temperature

Electrical Power only, just during on phase

Now let us see what the simulation might look like if we

assume unmeasured electrical power as the only source of

excess power. In this simulation, the peak power instead of

being 810 W is now 2250 W.

We find that again, the shape is too sharp to be a good match

to the Levi report.

The magnitude of the deviations are also too large:

∆T = 40 C, ∆P=200 W.

Sim properties are

scalef=0; % No LENR

COP=1.0;

Pelec=2250; % W peak, duty cycle=35%

no LENR

power

Add DC to measured AC

If we instead assume that there is a DC offset in the input

power, then the graphs look like these.

The corners are too sharp, but this time the deviations are too

small (15 C, 80 W). This then also does not look like a good fit

to the published data.

Sim properties are

scalef=0; % No LENR

COP=1.0;

PelecPulse=810; % W peak, duty cycle=35%

PelecDC = 540; % W, DC

Change construction slightly

While one might consider the previous plots to favour the

possibility that an internal reaction may be generating excess

heat during the pulses, we must admit that we do not know the

details of the reactor construction. In particular, we do not

know how good the thermal contact is between layers, and we

do not even know what all the layers are.

Let us change the estimated constructino of the reactor only

slightly by adding a thermally insulating (or bad thermal

contact layer) between heater block and outer steel shell.

reduced thermal

conductivity layer

LENR on all the time

While the shapes seem nicely rounded, similar to the shapes

Levi measured, one finds that the amplitude of the

oscillations are too small to be considered a good fit.

∆T = 8 C, ∆P = 45 W (compare to 25 C and 110 W)

scalef=1.0; % LENR scaling factor

COP=3.0; % Coefficient of performance

Pelec=810; % W peak, duty cycle=35%

LENR on only during on phase

Only allowing LENR during the pulse this time gives about the

correct temperature and power variation. The shape is also

about right.

scalef=2.7; % LENR scaling factor

COP=2.9; % Coefficient of performance

Pelec=810; % W peak, duty cycle=35%

Power only during on phase

However, with the insulating layer construction, one also gets

the correct temperature and power variation, and the correct

shape. Within the unknowns of the construction, this is

considered an acceptable fit. This time, though, there is no

LENR, just a large unmeasured electrical input power during

the pulse.

scalef=0; % LENR scaling factor

COP=1.0; % Coefficient of performance

Pelec=2250; % W peak, duty cycle=35%

Add DC to measured AC

If one assumes a DC offset to the electrical power, present

during both the on and off part of the cycle, one gets the

rounded shape, but the amplitude of the variations is too small.

∆T = 8 C, ∆P = 45 W (compare to 25 C and 110 W)

This again seems a poor fit to the published data.

scalef=0; % LENR scaling factor

COP=1.0; % Coefficient of performance

PelecPulse=810; % W peak, duty cycle=35%

PelecDC=540; % W, DC

Summary

A simulation has been written to try to simulate some of the figures published in the Levi report on

Rossi's Hot-Cat.

After constructing a reasonable approximation of the Hot-Cat, four scenarios were simulated:

1, LENR present during both the on and off parts of the cycle,

2, LENR present only during the on part of the cycle only,

3, Excess electrical power (no LENR) present during the on part of the cycle only,

4, Excess electrical power (no LENR) present during the on and off part of the cycle.

This was done for two possible Hot-Cat constructions:

A, all parts in perfect thermal contact, and no insulating layers,

B, an insulating layer (which may just be a poor thermal contact) between the resistors and outer steel

cylinder.

From these, it seems that combinations 2A, 2B and 3B seem acceptable fits to the data. It is significant

to note that while scenarios 2A and 2B involve LENR, scenario 3B does not. The other combinations

do not seem to provide good fits to the data, but it may be possible to attain better fits assuming

different Hot-Cat constructions. In the absence of further information, then, one cannot be convinced

that the results are due to LENR. Even in the case of 2A and 2B, one needs to explain why the reaction

is on only during the ‘on’ time, when the internal temperature is still several hundred degrees celsius

during the off time.

To distinguish between these scenarios, one would need a proper control run, where exactly the

same power schedule (including any trade-secret waveforms) be provided to a live and a dummy Hot-

Cat. One also notes that a record of the inner thermocouple readings also provides very good

diagnostics for the presence/absence of power generated in the innermost layers. As this thermocouple

is already in place, these values should also be recorded.

Further thoughts – temperature trend

Power loss due to

radiation and

convection

LENR power from Penon report

In order to maintain the outer temperature at a particular value, the losses due to radiation and convection need

to be maintained. The power to do this is shown in the red curve in the above plot (using the equations from the

Levi report).

The assumed LENR power taking the Penon report at face value is shown in the blue curve (see

http://www.slideshare.net/brslides/rossi-hotcat-penon-report-simulation for how this was attained).

The most obvious thing to note here is that the higher the temperature, the less the value of COP, and that the

reaction will not run away. This contradicts the Levi report in that the December test, which was assumed to be

more efficient as it ran at higher temperature, and that an earlier test did in fact run away to melt down. To

make the Penon/Levi reports consistent, one would need entirely different LENR vs Temperature plots for what

is presumably the same nickel/hydrogen powder.

Further thoughts – electrical measurement

In the appendix of the updated Levi report, the above figures can be found.

The three voltage waveforms look ok, sinusoidal with a peak voltage of 320 V and RMS voltage of 229 V.

The current waveforms consist of two pulses, with peak values of about 5.5 A and RMS value of 1.47 A. The third wire

seems unused.

The PCE connection is in wye format, as it measures the voltages wrt neutral.

Some comments on the above will be found in the following slide.

This figure shows a simulated voltage trace (sinusoidal) and two current traces (red and magenta). The instantaneous

electrical power can be calculated as the point-by-point product of these curves, then the average can be taken to

get the average power. The average is obviously very sensitive to the phase-position of the current pulse.

As the PCE-830 displays the RMS current, a question arises: does it take the average power as the product of RMS

voltage by RMS current? If so, it would overestimate the true electrical power, no matter what the pulse phase-

position is (this was confirmed with the above simulation). Using RMS values would have the effect of lowering the

measured COP. Hence this would not be a means of finding a COP>1.

Of course, if it takes a point-by-point power measurement, then it will come to the correct value, assuming no DC

offsets are present. It has been pointed at on many internet forums that the PCE can measure neither DC current nor

DC voltage. Hence the comments in the Levi report that no DC was present is not a safe assumption.

Further thoughts – electrical measurement

Further thoughts – electrical measurement

The appendix in the Levi report shows the test connection in the wye format, and traces imply one wire is unused.

What if the actual connections were in the delta format?

L1

L2

L3

N

I1

I2 V2

V1

I1

I2

V12

A delta connection with no current in L3 is now a single phase system! Also note that I1=-I2.

The average power calculated in the wye format with Vrms=225 V, Irms=1.47 A is

Pwye = I1*V1 + I2*V2 = 225*1.47 + 225*1.47 = 661 W

and in delta format is

Pdelta = V12*I1 = sqrt(3)*225*1.47 = 573 W

There is only a difference of 15% between these calculations, so again this is not enough to account for a COP of 2.6.

L1

L2

L3

N