Thanks Ed. Thing is I trust your
research more than mine :)
Would have been nice if chart had numbers in the 180 - 220F range,
which is where my interest is. (I thought it went to 100C.)
Not sure I understand why specific heat is not directly
proportional with density. But I don't know if 50/50 antifreeze is
by volume or weight.
Anyhow, looks like I don't have to worry about coolant flow.
Looking at past postings, I saw a remark about the Renesis pump
apparently being more effective that the 13B pump in spite of the
cheap impeller.
Perhaps that's why I'm getting better gal/min flow numbers in
spite of my estimated collective 0.4 sq in restriction (2 x 0.5"
ID) in spite of others 1" ID 0.8 sq in hose installations.
I guess I should have posted spreadsheets showing gal/min for
different RPMs rather than my inches of H2O head on pitot/static
sensors. Could easily be misread by someone in the future. Has to
use the WaterFlow.xls to convert measured head pressure to gal/min
and entered pipe area is critical.
Finn
On 2/27/2022 11:19 AM,
eanderson@carolina.rr.com wrote:
Well Looking
at the chart you referernced it looks like the mixture for
50/50 the CP could range from 0.79 at -30F to 088 at 100F.
IF 100 % glyco then at -10F we have a CP of 0.53 and at 100
0f 0.66. So looks like I picked a worst/best case
condition. But, using your example I get a cp of 0.8807.
Not a 30% difference but more than 5%
In any case, I
would suggest if you find data you feel more confident in,
do not hesitate to subsitute it.
Ed
pecific Heat of Ethylene Glycol based Water
Solutions
Specific Heat - cp -
of ethylene
glycol based water solutions at various temperatures are
indicated below
| Specific Heat - cp (Btu/lb oF) |
Ethylene Glycol Solution
(% by weight) |
Temperature (°C) |
| -50 |
-40 |
-30 |
-20 |
-10 |
0 |
10 |
20 |
30 |
40 |
50 |
60 |
70 |
80 |
90 |
100 |
| 0 |
|
|
|
|
|
1.0038 |
1.0018 |
1.0004 |
0.99943 |
0.99902 |
0.99913 |
0.99978 |
1.0009 |
1.0026 |
10049 |
1.0076 |
| 10 |
|
|
|
|
|
0.97236 |
0.97422 |
0.97619 |
0.97827 |
0.98047 |
0.98279 |
0.98521 |
0.98776 |
0.99041 |
0.99318 |
0.99607 |
| 20 |
|
|
|
|
|
0.93576 |
0.93976 |
0.94375 |
0.94775 |
0.95175 |
0.95574 |
0.95974 |
0.96373 |
0.96773 |
0.97173 |
0.97572 |
| 30 |
|
|
|
|
0.89373 |
0.89889 |
0.90405 |
0.90920 |
0.91436 |
0.91951 |
0.92467 |
0.92982 |
0.93498 |
0.94013 |
0.94529 |
0.95044 |
| 40 |
|
|
|
0.84605 |
0.85232 |
0.85858 |
0.86484 |
087111 |
0.87737 |
0.88364 |
0.88990 |
0.89616 |
0.90243 |
0.90869 |
0.91496 |
0.92122 |
| 50 |
|
|
0.79288 |
0.80021 |
0.80753 |
0.81485 |
0.82217 |
0.82949 |
0.83682 |
0.84414 |
0.85146 |
0.85878 |
0.86610 |
0.87343 |
0.88075 |
0.88807 |
| 60 |
0.72603 |
0.73436 |
0.74269 |
0.75102 |
0.75935 |
0.76768 |
0.77601 |
0.78434 |
0.79267 |
0.80100 |
0.80933 |
0.81766 |
0.82599 |
0.83431 |
0.84264 |
0.85097 |
| 70 |
0.67064 |
0.67992 |
0.68921 |
0.69850 |
0.70778 |
0.71707 |
0.72636 |
073564 |
0.74493 |
0.75422 |
0.76350 |
0.77279 |
0.78207 |
0.79136 |
0.80065 |
0.80993 |
| 80 |
0.61208 |
0.62227 |
0.63246 |
0.64265 |
0.65285 |
0.66304 |
0.67323 |
0.68343 |
0.69362 |
0.70381 |
0.71401 |
0.72420 |
0.73439 |
0.74458 |
0.75478 |
0.76497 |
| 90 |
|
|
|
0.58347 |
0.59452 |
0.60557 |
0.61662 |
0.62767 |
0.63872 |
0.64977 |
0.66082 |
0.67186 |
0.68291 |
0.69396 |
0.70501 |
0.71606 |
| 100 |
|
|
|
|
0.53282 |
0.54467 |
0.55652 |
0.56838 |
0.58023 |
0.59209 |
0.60394 |
0.61579 |
0.62765 |
0.63950 |
0.65136 |
0.66321 |
I'm not sure how
------ Original Message ------
Sent: 2/26/2022 9:29:22 PM
Subject: [FlyRotary] Re: Ed's spreadsheet
From your 24 Aug 2012 post about
cooling section in the spreadsheet:
"Cooling mass flow is dependent on:
1. A 0.7 cp compared to pure water
of 1.0 Cp - this compensates for the typical anitfreeze
dilution of the specific heat of water. "
Roughly weighing a 1 Gal 50/50 antifreeze jug I get
maybe 7.9 pounds after subtracting 0.3 pound for the
jug). Pure water about 8.3 pounds. That's about 5%.
I realize it changes somewhat with temperature but
nowhere near 30% ?
https://www.engineeringtoolbox.com/ethylene-glycol-d_146.html
Difference between water and 50/50 at 100C: 1000/1030 or
3%. Not 30%.
Difference in specific heat (whatever that is): 1.0079 /
0.88807 = 13% (for 50/50 at 100C).
What am I missing?
Finn
On 2/26/2022 10:48 AM,
eanderson@carolina.rr.com
wrote:
I agree, must have got it from someplace credible -
like Bill Shertz.
CP was 1.0 for pure H20 and somewhat less with
antifreeze mixed in.
I had a primary pully from MazdaTrix that reduced water
pump speed - since engine was turning faster than normal
in automobile, did not want to have any cavitation. So my
water pump did turn a bit slower than stock.
Not necessarily - note that water flow drops off if
pump speed increases into the "caviation range"
------ Original Message ------
Sent: 2/25/2022 10:39:43 AM
Subject: [FlyRotary] Re: Ed's spreadsheet
Thanks Ed.
But 185.85 seems pretty detailed for a SWAG.
Any chance you got it from Bill Shertz's tests (which
I unfortunately can't find the posts about)?
What determines "Cp Coolant"?
Heat transfer efficiency from engine to water and
water to rad?
From measuring the rims of the e-shaft pulley (122mm)
and water pump pulley (112mm) it looks like the
Renesis water pump runs a bit slower (factor 1.09
compared to your 1.18).
Should water flow be directly proportional to water
pump RPM?
Finn
On 2/25/2022 10:07 AM,
eanderson@carolina.rr.com
wrote:
Sorry, Finn.
Too much water under the bridge, pretty sure I
did not make it up out of thin air. I suspect I
visited some pump websites to arrive at a SWAG.
Ed
------ Original Message ------
Sent: 2/24/2022 2:25:56 PM
Subject: [FlyRotary] Ed's spreadsheet
Hi Ed,
From where did you get the
13B coolant flow numbers (Pump Factor)?
I want to be certain that
I have adequate coolant flow.
Finn
---