On Sep 4, 2:19=A0pm, Robert Redelmeier <red...@[EMAIL PROTECTED]
> wrote:
> Robert Myers <rbmyers...@[EMAIL PROTECTED]
> wrote in part:
>
> > You don't really need to understand the Navier Stokes equations,
> > but, if you don't, perhaps you should take a deep breath before
> > trying to instruct a fluid mechanicist about aerodynamics,
> > especially the poorly understood aerodynamics of a helicopter
> > descending into its own downwash.
>
> But I sometimes use CFD professionally, albeit usually on
> denser two-phase systems. =A0My experience has been that brute
> force "sharpening the pencil" with better inputs or more rigorous
> calculations seldom helps. =A0There is usually some assumption
> [boundary condition] that is wrong. =A0Fix it! =A0In this case,
> I'd suspect tip recirculation, fuselage or tail rotor effects.
>
I don't understand the "vortex ring state" problem, and I suspect that
no one does. There is no model that I know of that could cope with
the incredibly complicated fluid mechanics, aeroelasticity, and
control system (autopilot) issues. That I was arguing with someone
who wouldn't know a pole from a zero says it all. You can leave out
the Navier-Stokes equations. If you wrote down x+iy, she wouldn't
know what you meant, and yet, because she'd sat around the dinner
table listening to others who also didn't know what they were talking
about, she presumed to lecture me. The perfect model of a slashdot or
usenet poster.
As to using CFD codes professionally, there is a *really* bad code out
there that claims to be able to do everything and that it is widely
used. The code certainly can run to completion on many problems. In
order to understand why it can't possibly be doing what it claims to
be doing, you do need to understand some fairly deep things about the
N-S equations. At that, I'm more of a scientist or an applied
mathematician than an engineer. If engineers get what they need from
it, who am I to second guess them? Just as long as they don't try to
educate me about things I've spent years studying.
> >> > I get Terje.
> >> I do not think you do.
> > How would you know? =A0You've spoken to him?
>
> No, neither have you mentioned having done so. =A0I do not
> need to know Terje to have strong doubts that you do.
> Your idea of knowledge appears utterly foreign.
>
Terje first became aware of me when I first publicly questioned
reliance on caches. We've corresponded, we've met, and we've talked.
I've learned a lot more from him than he has from me, but I have a
pretty good idea of how he thinks, and it isn't nearly in the broad
brush style that the quote you took would indicate. What impresses me
most about him is that it is clear to me that he does not rely on the
wisdom of others. He does his own thinking and stands or falls on the
worthiness of it.
> >> Then why do you keep responding? How could I or anyone else
> >> be worse offended when you already drop technical openers?
> > What?
>
> I'm presuming you reply to avoid offending someone.
> Otherwise, I'm at a loss to explain why you continue
> a conversation you posted is a waste of time.
>
I'm sick of the BS. You've presumed to educate me about people I know
better than you do, fluid mechanics, rhetorical style, and even
Nineteenth Century French poets. Enough, already. I'm certain you're
smart, why this apparent need to overstate the case? Or aren't you
aware when you sound patronizing?
And, oh, yes, I do often sound patronizing and, no, I'm not always
aware of it. Sometimes, as at places in this exchange, I know exactly
what I'm doing.
> > There is no quotation, citation, factoid or principle of life
> > drawn from the foundations of Western civilization that will
> > substitute for imagination and a willingness to think for yourself.
>
> Bravo! =A0But when did I ever claim it could? =A0I repeat
> quotations to give proper credit and as shorthand for
> much longer arguments. =A0They are of course rebuttable.
>
Tout ce que nous enseigne est farce.
It apparently bothered you so much that you felt compelled to suggest
that Rimbaud didn't really mean it. He meant it.
You could divide the world into those who believe what their parents
taught them and those who don't. I belong to the latter category, as
did Rimbaud. There's room for both styles, just as long as you're not
overly insistent about yours.
> > You've switched from how do I measure latency
>
> Which you did not answer.
>
Look up what David Wang has written here about his own latency
measurements and you'll understand why I think it's a total waste of
time. The raw number is just meaningless. Why should I measure
something that I that I think is meaningless?
> > to grandiose claims about a quotation
>
> What claims? =A0I said it had many layers of meaning.
> If you consider this "gradiose", everything must be.
>
"Many layers of meaning" is a phrase that a not very original English
professor would use over sherry after an incomprehensible seminar. To
quote Wallace Stevens, "Let be be finality of seem." In this case,
anyway. The statement says a lot about how Terje thinks. You don't
have to guess about the many layers of meaning he sees, because he's
talked about them publicly.
> > from someone I suspect you don't even know.
>
> The author of this quotation is not relevant to its value.
> It would mean the same had it been said by Bill Joy or Bill
> Gates (who I don't think could have thought it up). =A0I know
> Terje somewhat from reading his ASM postings for 10+ years.
> IIRC I also saw him at a meeting. I know Keith about as well.
>
But you're trying to educate me about what he meant, just as you've
tried to educate me about so many other things. It never occurs to
you that I might have a better idea than you do to begin with.
Robert.
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