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Missile Defense

Technology has always found its greatest consumer in a nation's war and defense efforts. Since the last attempts at a "Star Wars" defense system, has technology changed considerably enough to make the latest Missile Defense initiatives more successful? Can such an application of science be successful? Is a militarized space inevitable, necessary or impossible?

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rshow55 - 02:52pm Feb 23, 2003 EST (# 9241 of 9249)
Can we do a better job of finding truth? YES. Click "rshow55" for some things Lchic and I have done and worked for on this thread.

To get a sense of how flows work - and how critical geometry and magnitudes of flow variables like Reynolds number and Mach number can be, a whole generation referred to Milton Van Dyke's An Album of Fluid Motion - here are some things from it on the net: http://www.featflow.de/album/vanDyke.html#COVERPAGE

If you looked at the sections

Separation

Vortices

Instability

Turbulence

Shock Waves

and

Supersonic flow

-- you'd have a quick, useful orientation into why aerodynamics matters - and how critical things can be.

Another image - from Lamb's Hydrodynamics - might be useful, too. It shows a (large) picture of a laminar wing - and shows a (tiny dot) representing a cylinder with the same drag.

Shape makes a difference ! Too often, a difference that is a matter of life and death. On a afterburner problem, the Lockheed skunk works lost seven planes and seven pilots in succession - before coming up with a (barely adequate) solution for afterburner combustion stability. It is for reasons like that that I was assigned to look at problems in mixing and turbulence.

If someone had Van Dyke handy, and looked at plate 166 by Dimotakis - which shows how structured turbulent mixing is - it would be easy to see some of the problems - and the reason why - using structured turbulent flow mixing and flow choreography - increases in mixing rates for large scales of 1000 fold and more are possible. I'm proud of what we had working at AEA about that. Wish it hadn't been as tainted as it was by classification constraints.

The mathematics of how patterns of flow vary has been intractable - and one of the motivations (along with guidance problems, and other problems too) for my work on coupled equations, summarized in http://www.mrshowalter.net/nterface

Here is my old partner, Professsor Steve Kline of Stanford: http://www.mrshowalter.net/klinerec

"In fluids, the existence of the new crossterms permits us to organize our data conceptually. Perhaps the clearest way to get a sense for fluid motion is AN ALBUM OF FLUID MOTION assembled by Van Dyke. Again and again, as the pictures show, flow patterns change mode as the value of the flow parameters change. The number of different modes and patterns is now very, very large. Shifts in patterns are COMMONPLACE all through our flow data. Experience in fluid mechanics shows that, when values of the parameters are very different, very different patterns are to be EXPECTED. The existence of the crosseffects that our math shows makes such shifts expected."

I was given wonderful education - a very special education - for reasons the US government was sensible to worry about. There was a "catch" - - to do what I was assigned to do - I had to "not care" about territories - proprieties - and go ahead and solve problems where they were.

With no credentials at all - infiltrating the academic and engineering establishment - to solve problems that needed to be solved.

Sometimes, these days, it seems to me that some things are working out - though they've been very inconvenient for me - and inconvenient for the TIMES, as well.

rshow55 - 03:09pm Feb 23, 2003 EST (# 9242 of 9249)
Can we do a better job of finding truth? YES. Click "rshow55" for some things Lchic and I have done and worked for on this thread.

A prior posting, 9205 http://forums.nytimes.com/webin/WebX?8@28.XbVRafgx3f0.2196324@.f28e622/10731 is related to 9241 above, and includes this, along with supporting technical detail:

If flow geometry (on a space shuttle) is bad enough in even a small locality near the leading edge - so that local heat transfer is high enough - things burn through.

For instance - the substrate of a missing tile can quickly melt - and the adhesive from adjacent tiles can quickly be burned-ripped away in the turbulence.

Geometry is critical . Including local geometry around a single tile - or the place where a single tile was supposed to be.

Or local geometry that has been changed by a surface collision.

If you look at flow visualization pictures, it can be easy to see how critical geometry is in the kinds of flows that had to be occurring around the shuttle.

It should have been clear that the shuttle was vulnerable if tiles were injured - and a report from Stanford and Carnegie Tech a decade ago assumed that people could see that.

But people, much too often "believe only what they want to believe." That's how it is for human beings - unless enough crosschecking occurs that people can see for themselves in enough detail for good decisions.

. . .

Repression - and unconscious feelings and logics that bias decision - are essential for understanding how this kind of thing can happen - and how vulnerable we all are to such errors.

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