View Single Post
Old 01-25-2013, 07:52 PM   #436 (permalink)
Tesla
Master EcoModder
 
Join Date: Feb 2012
Location: Australia
Posts: 355

The Truck - '02 Nissan GU Patrol ST
Thanks: 5
Thanked 76 Times in 50 Posts
Quote:
Originally Posted by Sven7 View Post
Tried that on my laptop here (where the numpad is over letter keys) and it opened a History tab and a "save as" window. They say my generation is good at computers but sometimes I just don't know...
I got it to work, make sure the Numerals are locked (Num Lock), otherwise the keys have shortcut functions, then pres Alt key and 0176.


[QUOTE=Sven7;353004]I know we've been over this before, but isn't it important on wagons that the top of the rear portion doesn't "stick out" of the template? Ie, that we have to move it back until it forms a tangent with the trailing edge. Otherwise you have a vertical step before the boat tail starts.

Quote:
Originally Posted by aerohead
If the 'interference is so great as to be able to closely match top and sides we streamline the main body separately from the greenhouse,creating the 'combination form'.[/aerohead]

What do you mean by interference? Is that another way of saying pressure differential?
I think this is a case where a little knowledge is dangerous, Aerohead would intuitively know where you can cut corners and where you can't because of his vast experience in this field, he has said numerous times he put the template up as a safe, simple guideline to address rear aero issues, many vehicles fit the model well, some, particularly wagons and vans have the issue where max camber is usually at same point, around the drivers head position, but they have an extended roof line with a very shallow curve back.
I have no doubts that the template needs to be pushed back, the max camber dimension must still be used for the overall length, but the template should be slid back until it is just touching the rear roof line. How else could you apply it to truck trailers and rail cars etc.
Also in his reply a few posts back he mentioned about starting the side tapers at different points, depending on max width, so the greenhouse (window) portion may well begin at a different position in relation to the roof and the lower sides, this may result in 3 or more different scaled tapers, starting at different points, then the challenge is to merge these together as they converge by using a generous radius on corners and trying to observe the 22 rule.
The easiest and safest solution is to base everything on the largest dimension, but this also results in the longest tail, and does not provide minimal cross section if cut short. The ideal is the more complex multi taper, but you run the risk of breaking attachment with poor design, so mayme going for the ideal, and padding out a safety factor for the shorter tapers.
Don't know regards the inteference comment, he is deep within his knowledge and it sometimes sounds like code when he writes, I will understand one day.

Quote:
Originally Posted by Sven7 View Post
"advocated the tail truncation at 50% frontal area wake area to ease driving in traffic and parking issues."

How about you cut the tail in half and the smaller half moves in to nest inside the larger one when you need to park. Kinda like aero Russian nesting dolls.
I have thought about that telescoping idea, maybe incorporating semi solid segments with an inflatable bag inside to expand them??
  Reply With Quote