MECANICA DE FLUIDOS
MECANICA DE FLUIDOS
MECANICA DE FLUIDOS
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F( X,<br />
Y,<br />
Z)<br />
r<br />
T1.- INTRODUCCION A LA <strong>MECANICA</strong> <strong>DE</strong> <strong>FLUIDOS</strong><br />
3.- Ecuación de la Hidrostática (I)<br />
Presión de una columna de fluido<br />
( ρ V)<br />
g ρ ( h A)<br />
F W Masa g<br />
g<br />
p = = = = = = ρ<br />
A A A A A<br />
p = ρ g h<br />
g h<br />
1 m.c.a. (ρ = 1.000 kg/m 3 ) = 9.800 Pa<br />
1 m.c.Hg (ρ = 13.600 kg/m 3 ) = 133.280 Pa<br />
⎛ ∂p<br />
⎞<br />
p dz dy − ⎜p<br />
+ dx⎟<br />
dz dy + X<br />
⎝ ∂x<br />
⎠<br />
⎛ ∂p<br />
⎞<br />
p dx dz − ⎜<br />
⎜p<br />
+ dy dx dz Y<br />
y<br />
⎟ +<br />
⎝ ∂ ⎠<br />
⎛ ∂p<br />
⎞<br />
p dx dy − ⎜p<br />
+ dz⎟<br />
dx dy + Z<br />
⎝ ∂z<br />
⎠<br />
( ρ dx dy dz)<br />
( ρ dx dy dz)<br />
( ρ dx dy dz)<br />
= 0<br />
Elemento diferencial de volumen<br />
= 0<br />
= 0<br />
m = V ρ = dx dy dz ρ = 1<br />
∂p<br />
p ⇒ p + dx<br />
∂x<br />
Fuerza exterior:<br />
F( X,<br />
Y,<br />
Z)<br />
r<br />
T1.- INTRODUCCION A LA <strong>MECANICA</strong> <strong>DE</strong> <strong>FLUIDOS</strong><br />
3.- Ecuación de la Hidrostática (II)<br />
⎛ ∂p<br />
⎞<br />
− ⎜ dx⎟<br />
dz dy + X<br />
⎝ ∂x<br />
⎠<br />
⎛ ∂p<br />
⎞<br />
− ⎜ dy dx dz + Y<br />
y<br />
⎟<br />
⎝ ∂ ⎠<br />
⎛ ∂p<br />
⎞<br />
− ⎜ dz⎟<br />
dx dy + Z<br />
⎝ ∂z<br />
⎠<br />
( ρ dx dy dz)<br />
( ρ dx dy dz)<br />
( dx dy dz ρ)<br />
= 1<br />
∂p<br />
∂p<br />
= 0 ⇒ ρ X = ⇒ ρ X dx = dx<br />
∂x<br />
∂x<br />
∂p<br />
∂p<br />
= 0 ⇒ ρ Y = ⇒ ρ Y dy = dy<br />
∂y<br />
∂y<br />
∂p<br />
∂p<br />
∂Z<br />
∂z<br />
( ρ dx dy dz)<br />
= 0 ⇒ ρ Z = ⇒ ρ Z dz = dz<br />
∂p<br />
∂p<br />
∂p<br />
ρ<br />
X dx + ρ Y dy + ρ Z dz = dx + dy + dz = dp<br />
∂x<br />
∂y<br />
∂z<br />
11<br />
12