Paul
I have read through my autographed copy of How to Cool Your Wankel twice
since Sun N Fun. I have a question about the cross counter flow heat
exchangers on page 24 and 25. If it is (a) well known fact that the rate
of heat transfer is a strong function of the difference between the
metal temperature and the cooling air temperature. How can passing the
coolest air through the coolest part of the heat exchanger first improve
the efficiency of the heat exchanger? What does the average difference
look like? Is it an exotic calculation?
Thank You
Robert White
P.S. I have not figured out the figure numbering system. Is there one?
R.W.


The true calculations are probably rather complicated because it is
a function of many things not the least of which is the thickness of
the cores.

The idea is to maximize the AVERAGE difference in temperature for
an over all improvement in cooling.

Does this modified chart help? Delta T1 is supposed to be greater than delta T3.
and delta T2 is supposed to be greater than delta T4.

Here is an older version of the chart you might find easier to understand.
At least it is different.

This was discovered by Franklin in the early 1930's and is why
most air cooled aircraft engines are down draft cooling. The cold air
is passed over the coolest part of the engine first. Namely the top of the
engine. The hotter exhaust is on the bottom of the engine.

No consistent figure numbering system yet. Sorry. Perhaps in the fifth edition.
Books are like software. The customer can always find bugs :)
I am new at writing books and I had no editor to help me out.
I merely used the figure numbers that came from the source of the figures.


Paul Lamar ...No rotor no motor.

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