In front, on top, and behind the oil cooler, all
kind of look like laminar flow airfoils.

Tony

That is the early P51. Models after the war had
K&W curves as did the B36.

Paul Lamar


Hi!

Constructing low turbulence wind tunnel and measured air
flow separation. I guarantee that in expansion part of
presented channel there will be a fluid flow separation
which will parially shadow cooler. Please, put turbulators
inside surfaces at the start of air expansion area. It can
be any kind of parts cca 1-2mm in diameter. Make this
surface section rough.

B.r.

Viktor

Faculty of Mechanical Engineering
University of Ljubljana
Slovenia

This is no longer necessary. In fact it slows the flow into the duct.
Viktor, IMHO you have been isolated through no fault of your own
for the years 1945 to 1990 and missed some developments
in Aerodynamics. Two major books were published in English
by German scientist that have become classics. "Fluid Dynamic
Drag" by S. Hoerner in 1965 and The "Aerodynamics of Propulsion"
by Kuchemann and Weber in 1953. These men did applied research
on flow inside diffusers. I republished some of this work
in my book "How to Cool Your Wankel". Some of these books
are available from time to time used on the internet but
quite expensive.

Aerodynamics of Propulsion By Kuchemann and Weber is
near impossible to find.

There is only one copy of Fluid Dynamic Drag by S. Hoerner
in bad shape for $75 on Ebay. 9 days left to bid.

Item number:    130358647707
Item location:    Palm City, Florida, United States
Ships to:    United States, Europe


Do you plan on attending Aero in April at Friedrichshaven
this year? If so I will put the books in my luggage and
we can get together and discuss them when I get there.

Pipistrel, made in your country. is doing very well selling
light sport aircraft world wide. They had a large presence
at Aero last year.


PIPISTREL d.o.o. Ajdovsc(ina
GORISKA CESTA 50a
SI-5270 AJDOVSC(INA
SLOVENIA
tel.: +386 5 36 63 873
fax.: +386 5 36 61 263

----------------------------------------------------------------
Have you seen this paper?

http://protonet.org/doc/Liquid_cooling_5_LTR.pdf

tonys longez

------------------------------------------------

Yes. Good work.

--------------------------------------------------

On the whole it is good work but there is at least one
error.

The attached chart and the table do not correlate.
a,b,c,d, etc.,etc.. are used to label the curves
while numbers are used in the table.

The curve labeled "a" in the lower graph is the K and W
diffuser. The coordinates of which are in my book.

Paul Lamar


Hi!

Read the paper. Exactly what I am talking about. Small surface curvature + high pressure gradient + unstable laminar boundary layer = separation. Sometimes helps tripping the laminar boundary layer with turbulator to turbulent boundary layer, which is more immune to separations. Separations are usually measured with hot-wire or lda/ldv but cheap visualization with smoke and strobe photography can help. On the picture red circles are recommended locations for turbulators and red curve is small correction to increase curvature radius and decrease probability of separation. Turbulators will increase drag by small amount but with shadows eliminations could increase cooling efficiency.

Pipistrel (in Italian meaning flitter-mouse) is one of tree companies in Slovenia which produce general aviation airplanes. Their aircrafts are made from epoxy-fiberglass and carbon fiber. Aircrafts are made with sailplane philosophy in mind + small engine. Result: safe, light, laminar, long range, cheap (low drag - small engine) and low cost of ownership aircraft. Highly recommended.

Kindly asking for help in drawing renesis 13b and 16x engines in 3D modeler software (Catia and SolidWorks). Need dimensions, locations of attaching points, intake and exhaust ports, and all data, which can improve quality of engines drawings. Even (planar) photographs can help. Accepting most of known graphic formats. Thank you very much.

B.r.

Viktor

Slovenia

Yes I read the paper professor :)
That is obsolete thinking. K&W and K&L came up with something better
after the war. That stuff is 70 years out of date. Where have you been? :)

I have some 3D's of the Mazda rotary engines in igs zip file format that
can be loaded into solid works. Can you receive zip files?

Paul Lamar