Well, since the OP of the thread has stated that aerodynamic discussions are welcome in his thread and since I have done some research to answer my own question in the post above. Though I would share.
To rehash, my basic question was "
How abrupt/short of an aerodynamically shaped tail angle can you get away with without that nasty separation problem producing an oversize wake compared to just using a shorter tail with shallower angle then a sharp cut-off (Kamm tail) instead?"
I found my answer in a model aircraft design book I had in my technical book collection. The answer was found in the books section that specifically addressed model thermal soaring sail-plane design where the author addressed "Pod-&-Boom" style aircraft design and how they can actually by superior not only in terms of weight savings but surprisingly also can have slightly less parasitic drag then a conventional fuselage tail design. Apparently some Australian guy proved the theory by not only theoretical research in wind tunnel testing but also breaking the wold record with a "Pod-&-Boom" style full size thermal soaring sailplane and then breaking his own record several more times something that up until he did so was scoffed at and "Pod-&-Boom" style sailplanes were previously considered to be always inferior in terms of aerodynamic drag compared to a conventional design. Basically how it works is that although a sharper angle at the rear of the fuselage pod may produce slightly more parasitic drag this can be more then offset by the reduction in parasitic skin drag produced by a conventional long taper tail resulting in an over all reduction in parasitic drag provided a proper shape form is used for the pod. The specific forms recommended for use are the "Young 50% and 60% laminar flow low drag body forms" preferably applied in a three dimensional circular form around a slightly convex upward curved mean camber line to match the slight up draft forward of the wing mount and downdraft aft of the wing mount that is naturally created by lifting wing.
Now if your eyes glazed over with that technical mish-mash, let me simplify it by simply stating that "
Long story short; all the research has already been done for us already by the guys who engineer both full scale manned and model thermal soaring sailplanes as far as what best aerodynamic shape you can use for a reasonably short length pod that you can cram a human being or two into (or in the case of a model the RC equipment) and still have good to excellent aerodynamics. So we don't have to reinvent the wheel we can borrow from all the work the thermal soaring sailplane boys have been doing for decades."
An illustration I took a minute to throw together and colorize to illustrate a
Conventional Tail Sailplane Fuselage Vs.
Pod-&-Boom Sailplane Fuselage (for copyright issue reasons I didn't want to just scan the illustrations in the book although they are admittedly superior but you get the idea):
The aerodynamic profiles that have been developed for the shape of that forward pod is what are desired, and I was able to find the ordinate tables for four of the "Young laminar flow low drag body forms" namely the 30%, 40%, 50%, and 60% forms (their might be others but besides that but those were the ones I was able to track down the actual profile ordinates for.) From the second source that had the actual plotting ordinates I further learned that all of these profiles have been proven as very low drag at reasonable attack angles in most normal applications with only a very small turbulent wake coming off the very tip of rear tail of the profiles. They are so named for the normal average percentage of the forward flow that is in true laminar flow with the remainder of the flow being laminar flow over a thin turbulent flow skin bubble which is not true laminar flow but is also not turbulent flow separation either which is where you get large turbulent wakes and heavy drag.
The ordinates for the 60% laminar flow profile are as follows (copied straight from my source by hand and triple checked for typos, just doing this one of the four that I liked best for now):
Young 60% Laminar Flow Low Drag Body Ordinates
From Nose To Tail:
At % Of Length = Perpendicular % Of Length To Outer Surface
(Symmetrical, One Side Given, Flip For Other Side.)
000.0% = 0.000%
0.1% = 0.335%
0.2% = 0.620%
0.3% = 0.770%
0.4% = 0.899%
0.5% = 1.000%
1.0% = 1.460%
1.5% = 1.800%
2.0% = 2.100%
2.5% = 2.336%
5.0% = 3.405%
10.0% = 4.938%
15.0% = 6.085%
20.0% = 7.002%
25.0% = 7.781%
30.0% = 8.462%
35.0% = 9.048%
40.0% = 9.520%
45.0% = 9.845%
50.0% = 9.991%
55.0% = 9.921%
60.0% = 9.612%
65.0% = 9.047%
70.0% = 8.223%
75.0% = 7.150%
80.0% = 5.860%
85.0% = 4.399%
90.0% = 2.860%
95.0% = 1.314%
97.5% = 0.613%
100.0% = 0.000%
When plotted in CAD and a smooth curve surface fitted to the points and then flipped for the other side this is what you end up with, bottom one of the four is the 60% laminar flow form:
All of the forms are 1/5 of their length wide at their widest point and the 60% form gives the most open room in the middle for the narrowest width and thus shortest overall length and also has the shortest tail section that will still work aerodynamically which is needed for what I have in mind.
Previously this is what I had in mind for the build I'm in the planning stages of:
Basically a two wheeled design that is tall and narrow and can lean into the turns and doesn't have my way down low so I can see and be seen in traffic but is still as close to a "high speed human/electric hybrid land torpedo" as possible.
After learning about these proven sailplane pod profiles I've changed over to them in my design work at the sacrifice of gaining 33" in additional length (12" longer nose and 21" longer in the tail with the rear wheel having to be moved back 12" further) and 3" in additional width and a slightly narrower front wheel turning movement but I think the potential performance gains in terms of aerodynamics should be well worth it:
From that basic idea I've reworked where I'm at in my design phase to this point:
Basic idea in colorized easy on the eyes views:
(Center Top To Bottom = Top View, Bottom View, Side View. Upper Left = Front View. Upper Right = Rear View)
More technical layout including vertical profile cross-sectioning on 6" increments (clickable to larger size):
As you can see only the third cross section up (12" up from bottom of body, 18" up from ground) is absolutely true to the Young 60% Low Drag Body form and all the rest of the other cross sections are not the exact form but never is the tail section any more aggressively angled then that form and where necessary in some of the upper cross sections a small Kamm tail is allowed (which should actually work out well as a good place to mount brake/tail lights) thus hopefully ensuring that at least in normal use there should not be any turbulent wake separation issues.
Anyway that's where I'm at in current and anyone else is certainly welcome to use the proven body form of the Young 60% Low Drag Body which is apparently well proven as a highly effective low drag pod shape in the thermal soaring sailplane area where aerodynamics are a huge factor.
YMMV especially since this is all theory on my part at least so far but thought I would throw it out there for those who may be interested.
My next velo/streamliner will be more about speed, and less about practicality and comfort.
