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On Fri, Jun 17, 2011 at 12:48 PM, Fons Adriaensen wrote:
> For a real single sound source the direction of the

quoted text
> vector V(t) is that towards the source, and P(t) and

> V(t) in any given point are closely related. They are

> of course measured in different units (Pascal, and

> meters/second resp.), one is a scalar and the other

> a vector, but they are proportional.

This doesn't matter to the rest of your analysis/description, but I'd offer

a correction to this paragraph.
V(x,t) is proportional to the spatial gradient of P(x,t).
Note that this means pressure and velocity waves are 90 degrees out of sync

with each other.

One clear case this matters is the boundary conditions at walls.  The volume

velocity goes to 0 at the wall (Dirichlet), but the pressure has the

requirement that its 1st derivative is 0 (Neumann).
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On Fri, Jun 17, 2011 at 12:48 PM, Fons Adriaense=

n <fons@linuxaudio.org> wrote:
For a real single sound source the direction of the

vector V(t) is that towards the source, and P(t) and

V(t) in any given point are closely related. They are

of course measured in different units (Pascal, and

meters/second resp.), one is a scalar and the other

a vector, but they are proportional. This doesn't=

 matter to the rest of your analysis/description, but I'd offer a corre=

ction to this paragraph.V(x,t) is proportional to the spatial gradi=

ent of P(x,t).

Note that this means pressure and velocity waves are 90 degrees out of =

sync with each other.=A0 One clear case this matters is the boundary co=

nditions at walls.=A0 The volume velocity goes to 0 at the wall (Dirichlet)=

, but the pressure has the requirement that its 1st derivative is 0 (Neuman=

n).=A0

=A0
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