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Re: Tear drop

To: Pork Pie <pork.pie@t-online.de>,
Subject: Re: Tear drop
From: W S Potter <wester6935@attbi.com>
Date: Sat, 04 Jan 2003 13:42:36 -0800
That makes sense.  Thanks for the clarification.

What would you say about the shape of the McBride/Moreau liner using this
description?

Wes

on 1/4/03 12:00 PM, Pork Pie at pork.pie@t-online.de wrote:

> Okay, this question is very serious, so I sit down and give some more
> information.
> 
> The last week, someone wrote that a square got a Cd from 1,0. If he meant a
> flate plate standing in the air than is this figure wrong. by a very low speed
> it's 1,0 - by high speed and using the Reynolds number the Cd of a flate,
> square plate is 1,28.
> 
> The teardrop - 3.5 times length to the total width is the minimum base for
> good effective tear drop - this will bring you a result which is 1/32 of a
> flate plate Cd.
> 
> If you go to a 6 to one, the aerodymic will be much more effective.
> But carefully. This kind of teardrop is everywhere round - it means - on the
> front you start with a radius and from there on - when you go sideways, you
> increase the radius size, bigger and bigger, so that at last this radius left
> and right joint to the rear end.
> The radius increase follows a mathematical 6 degrees curve after the biggest
> cross sestion of the teardrop.
> A teardrop with a radius in front and than a straight line to the rear end
> needs the 6 degrees rule.
> Confussed enough? If you need more information, I can make a sketch to explain
> this.
> So let me know if there is not everything clear.
> 
> See ya
> 
> Pork Pie
> 
> 
> 
> <wmtsmith@landracing.com> schrieb:
>> Jon, I read that a teardrop needs a 4 times length to width to be
>> effective--I am trying to use a 6 to one.
>> 
>> Now the question I don't know--do you figure 1/2 the width and that is the
>> relationship for just that side or do you have to use total width? wmts
>>> 
>>> From: "Jonathan Amo" <webmaster@landracing.com>
>>> Date: 2003/01/03 Fri PM 09:47:52 EST
>>> To: "LSR List" <land-speed@autox.team.net>
>>> Subject: wisdom or not wisdom
>>> 
>>> List,
>>> 
>>> Im out here, just reading and accepting and analyzing what I read as in does
>>> it make sense and can I contribute or take the information and put it to
>>> use.
>>> 
>>> I do have a question as to streamlining.
>>> 
>>> Jack C I really want you to pop in about this subject.
>>> 
>>> We all have heard that a teardrop shape is "sapposed" to be the most
>>> areodynamic shape. Even thinking about one of those rainbow trout. No Keith
>>> not those brown trout you probably fish for. At what point does this shape
>>> not
>>> be benefit. What length in otherwords would this shape be or not be
>>> beneficial? 5ft? 10ft? 25ft?
>>> I have heard that the air coming around the subject if to short will
>>> "collide"
>>> at the rear of the subject, if it does not have time to smooth out. So how
>>> long does it need to smooth out?
>>> 
>>> Anybody have any beneficial info on the subject.
>>> 
>>> Jonathan
>> 
>> 
>> 
>> 
> 
> ------

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