- Male
- 68
- from Sydney,Australia
- Member since May 10th 2015
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Posts by RobertBryant
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Of course you know what it is. Of course you can give bounds. It is right there in Fig. 4. The velocity is uniform across 60 mm of the 66 mm orifice. The velocity cannot possibly drop abruptly to zero in the last 3 mm.
There were velocity profile equations in textbooks.. accurate to within 10-15%??
I remember using them.... profile depended on smoothness..
friction.
thirty years ago they were there... perhaps they have been lost in this era of software
perhaps I can find them by August.
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RB... what "techinal content" does the above have!
Blessings B2
Maybe B2 can contribute technically to what THHnew calls " 60pages of weird...".
If the GoogleX are interested in the technical discussion of a
putated likely 24% error in the anemometer readings
of R19.. and the intricacies of Reynolds number..
this may be a good post to track back from
Mizuno reports increased excess heat
Proverbs 12.18
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That is not what I want to do. However I truly think I'd need to be a saint not to so so - and I am no saint.
but I still can't see how you get likely 24% error without assuming retrograde velocity in the annular region
I did notice that the velocity spreads in the Mizuno data get less as the velocity increases
at v=5.0 m/s I get via Etoolbox an even higher ~ Re 21,000
this is consistent with a flatter profile at higher velocities
A full examination of this matter will require more than eyeballing
In the end it is rather futile ...although heroic considering it is unpaid effort
As I have pointed out an error of 10% or so systematic in both calibration
and active runs makes little difference to the COP.
The object of the calorimetry was to find the best COP
I guess it gave some direction towards finding the R20 's huge COP
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How do you get 10000???
I get ( via E toolbox)
16700 ... does that make a difference?
Complicated
maybe I made error?
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. You refuse to read my previous posts so I have to repost things many times.
I do read your posts especially this one
You should get paid heaps for your contribution to this froum
Umax(1 - r/R)^(1/n) where n = 5 from Re=10,000
How do you get 10000???
I'm so slow at fluid mechanics
Teach me..
Professor THH.
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what velocity profile does THHnew use to get likely 24 % error?
I'm just not sure because of the big difference between the equations for turbulent flow and the very flat measurements
What is the big difference
What are the very flat measurements you are using,
Please show numbers.
Show what you predict the measurements should be versus what you predict using equations
State all assumptions and equations
Not words
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although it may appear so to THHnew for whom fluid mechanics is weirdly novel
Let me suggest that Mizuno is far less of a newbie to fluid mechanics than is THHuxleynew.
and that the latter's immense contribution to over 60 pages of what he calls weird
is incommensurate with his knowledge
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I maintain that till these questions are answered you cannot know that the airflow here is non-standard
You can predict the average velocity flow in the annulus region based on standard physics with good accuracy.
In practice we used in our engineering department in a huge dirty and sprawling pulp and paper plant in the 1980's
a series of nomographs..
On occasion we would have to derive stuff from equations
it was horses for courses ...sometimes you needed to be 5% accurate sometime 10% with a simple triangular approximation
Its not rocket science
although it may appear so to THHnew for whom fluid mechanics is weirdly novel
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RB - this is like talking to a wall.
No its like talking to Ptolemy
what velocity profile does THHnew use to get likely 24 % error?
Is the velocity profile negative ... retrograde in the 3mm annulus
Is this the THHnew version of the Ptolemaic epicycle?
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you have no confidence in those figure
I have no confidence in this figure
lenr-forum.com/attachment/9153/
or this calculation
That is because at the temperatures I did this calculation (380C reactor vs 80C wall) the re-radiation is\\
less that 10% of the radiation due to the T^4 factor for relatively small gaps.
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No error bounds =>
As I have suggested
pls look at the effect of 0.5 degrees temp rise on calorific value and airdensity.
This will give you some minute error bound.
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The rod seems to have both concentric notching and a nodule almost drip-like
It looks to be a state of the art burnishing technique.
Gives better grip for 74 year old hands
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Your contribution above seems to be saying that a 17% error in the airflow does not matter.
It doesn't
the COP is the purpose.
Do you dispute any of my working
this is exacty on point.
state your velocity profile in the edge annulus
Is it zero over the entire 3mm
Yes or No?
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YOU WILL NOT PUT ERROR BOUNDS ON THE DATA IN THE PAPER.
THHnew has not even included the effect of area. why not?
and has not shown the edge annulus velocity profile
Even putting the edge area velocity unrealistically as completely zero gives an error of 17%
Does THHnew think that the velocity in the entire 3mm edge annulus is zero?
Rather than get into the nitty-gritty of the fleas on a dog's rear end
its better to first look at the purpose of the dog
Is it a police Alsatian a poodle or the next dish at a Shanghai restaurant?
The focus of the calorimetry is output/input.
Calorimetry measures mass flowrate m and temp difference delta T
A rough guide to output/ input is m x Cp x delta T
Lets say for the calibration/active the delta Ts are 3/3.5
Output = m x Cp x 3.5
Input= m x Cp x 3
Lets assume the error in m is 17% ..The systematic error due to
the edge annulus overestimate of velocity is 17%... unrealistically
Dividing Output/Input gives m x (1+17%) Cp x 3.5 divided by m x (1+17%)Cp x 3
Equals 3.5/3 ....COP = 1.17
The effect of a 17 % systematic error on the O/I is negligible.
COP equals 1.17 regardless.
Rather then a decontextualized myopic 24% pls look at the whole dog.
For further myopic investigation THHnew might look at the effect on COP
of an increased air density/ calorific value due to increasing the temperature by 0.5 C.
Then one can get some minute idea of the error bounds in the COP estimate
due to THHnew's purported 24% error
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For example, we only need the edge 3mm of the airflow to be very low, and we have a 20% error
This is wrong wrong wrong... and its not 24%????
show your assumed velocity profile and how this compares with the data
SHOW CALCULATIONS.....
if you can't do this
I will show you in August
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I truly think you have a conceptual error here in the way you approach this.
You are the one with conceptual errors.
That is because at the temperatures I did this calculation (380C reactor vs 80C wall) the re-radiation is\\
less that 10% of the radiation due to the T^4 factor for relatively small gaps.
show calculation please.
I need to check your conceptual errors.
I'll give you a week to come up with a calculation of 24% error.
then you can check with my calculation.