δ
u
v
=
[
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
u
↓
v
→
η
u
v
=
[
−
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
u
↓
v
→
g
u
v
=
η
u
v
−
2
Φ
⋅
δ
u
v
g
u
v
=
[
−
(
1
+
2
Φ
)
0
0
0
0
1
−
2
Φ
0
0
0
0
1
−
2
Φ
0
0
0
0
1
−
2
Φ
]
u
↓
v
→
g
u
v
=
[
−
1
1
+
2
Φ
0
0
0
0
1
1
−
2
Φ
0
0
0
0
1
1
−
2
Φ
0
0
0
0
1
1
−
2
Φ
]
u
↓
v
→
Γ
a
b
c
=
1
2
(
g
a
b
,
c
+
g
a
c
,
b
−
g
b
c
,
a
)
Γ
a
b
c
=
1
2
(
(
η
a
b
−
2
Φ
⋅
δ
a
b
)
,
c
+
(
η
a
c
−
2
Φ
⋅
δ
a
c
)
,
b
−
(
η
b
c
−
2
Φ
⋅
δ
b
c
)
,
a
)
Γ
a
b
c
=
1
2
(
(
−
2
Φ
⋅
[
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
a
↓
b
→
+
[
−
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
a
↓
b
→
)
,
c
+
(
−
2
Φ
⋅
[
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
a
↓
c
→
+
[
−
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
a
↓
c
→
)
,
b
−
(
−
2
Φ
⋅
[
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
b
↓
c
→
+
[
−
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
b
↓
c
→
)
,
a
)
Γ
a
b
c
=
1
2
(
−
[
[
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
0
0
0
0
0
0
0
0
0
0
0
0
]
c
↓
a
→
[
0
0
0
0
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
0
0
0
0
0
0
0
0
]
c
↓
a
→
[
0
0
0
0
0
0
0
0
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
0
0
0
0
]
c
↓
a
→
[
0
0
0
0
0
0
0
0
0
0
0
0
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
]
c
↓
a
→
]
b
↓
[
c
↓
a
→
]
+
[
[
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
0
0
0
0
0
0
0
0
0
0
0
0
]
b
↓
c
→
[
0
0
0
0
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
0
0
0
0
0
0
0
0
]
b
↓
c
→
[
0
0
0
0
0
0
0
0
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
0
0
0
0
]
b
↓
c
→
[
0
0
0
0
0
0
0
0
0
0
0
0
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
]
b
↓
c
→
]
a
↓
[
b
↓
c
→
]
+
[
[
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
0
0
0
0
0
0
0
0
0
0
0
0
]
c
↓
b
→
[
0
0
0
0
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
0
0
0
0
0
0
0
0
]
c
↓
b
→
[
0
0
0
0
0
0
0
0
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
0
0
0
0
]
c
↓
b
→
[
0
0
0
0
0
0
0
0
0
0
0
0
−
2
Φ
,
t
−
2
Φ
,
x
−
2
Φ
,
y
−
2
Φ
,
z
]
c
↓
b
→
]
a
↓
[
c
↓
b
→
]
)
Γ
a
b
c
=
[
[
−
Φ
,
t
Φ
,
x
Φ
,
y
Φ
,
z
−
Φ
,
x
−
Φ
,
t
0
0
−
Φ
,
y
0
−
Φ
,
t
0
−
Φ
,
z
0
0
−
Φ
,
t
]
c
↓
a
→
[
−
Φ
,
x
−
Φ
,
t
0
0
Φ
,
t
−
Φ
,
x
Φ
,
y
Φ
,
z
0
−
Φ
,
y
−
Φ
,
x
0
0
−
Φ
,
z
0
−
Φ
,
x
]
c
↓
a
→
[
−
Φ
,
y
0
−
Φ
,
t
0
0
−
Φ
,
y
−
Φ
,
x
0
Φ
,
t
Φ
,
x
−
Φ
,
y
Φ
,
z
0
0
−
Φ
,
z
−
Φ
,
y
]
c
↓
a
→
[
−
Φ
,
z
0
0
−
Φ
,
t
0
−
Φ
,
z
0
−
Φ
,
x
0
0
−
Φ
,
z
−
Φ
,
y
Φ
,
t
Φ
,
x
Φ
,
y
−
Φ
,
z
]
c
↓
a
→
]
b
↓
[
c
↓
a
→
]
Γ
a
b
c
=
g
a
d
Γ
d
b
c
Γ
a
b
c
=
[
[
Φ
,
t
1
+
2
Φ
−
Φ
,
x
1
+
2
Φ
−
Φ
,
y
1
+
2
Φ
−
Φ
,
z
1
+
2
Φ
Φ
,
x
1
+
2
Φ
Φ
,
t
1
+
2
Φ
0
0
Φ
,
y
1
+
2
Φ
0
Φ
,
t
1
+
2
Φ
0
Φ
,
z
1
+
2
Φ
0
0
Φ
,
t
1
+
2
Φ
]
[
−
Φ
,
x
1
−
2
Φ
−
Φ
,
t
1
−
2
Φ
0
0
Φ
,
t
1
−
2
Φ
−
Φ
,
x
1
−
2
Φ
Φ
,
y
1
−
2
Φ
Φ
,
z
1
−
2
Φ
0
−
Φ
,
y
1
−
2
Φ
−
Φ
,
x
1
−
2
Φ
0
0
−
Φ
,
z
1
−
2
Φ
0
−
Φ
,
x
1
−
2
Φ
]
[
−
Φ
,
y
1
−
2
Φ
0
−
Φ
,
t
1
−
2
Φ
0
0
−
Φ
,
y
1
−
2
Φ
−
Φ
,
x
1
−
2
Φ
0
Φ
,
t
1
−
2
Φ
Φ
,
x
1
−
2
Φ
−
Φ
,
y
1
−
2
Φ
Φ
,
z
1
−
2
Φ
0
0
−
Φ
,
z
1
−
2
Φ
−
Φ
,
y
1
−
2
Φ
]
[
−
Φ
,
z
1
−
2
Φ
0
0
−
Φ
,
t
1
−
2
Φ
0
−
Φ
,
z
1
−
2
Φ
0
−
Φ
,
x
1
−
2
Φ
0
0
−
Φ
,
z
1
−
2
Φ
−
Φ
,
y
1
−
2
Φ
Φ
,
t
1
−
2
Φ
Φ
,
x
1
−
2
Φ
Φ
,
y
1
−
2
Φ
−
Φ
,
z
1
−
2
Φ
]
]
a
↓
[
b
↓
c
→
]
let
Φ
~ 0, but keep
∂
Φ
to find:
Γ
a
b
c
=
[
[
Φ
,
t
−
Φ
,
x
−
Φ
,
y
−
Φ
,
z
Φ
,
x
Φ
,
t
0
0
Φ
,
y
0
Φ
,
t
0
Φ
,
z
0
0
Φ
,
t
]
[
−
Φ
,
x
−
Φ
,
t
0
0
Φ
,
t
−
Φ
,
x
Φ
,
y
Φ
,
z
0
−
Φ
,
y
−
Φ
,
x
0
0
−
Φ
,
z
0
−
Φ
,
x
]
[
−
Φ
,
y
0
−
Φ
,
t
0
0
−
Φ
,
y
−
Φ
,
x
0
Φ
,
t
Φ
,
x
−
Φ
,
y
Φ
,
z
0
0
−
Φ
,
z
−
Φ
,
y
]
[
−
Φ
,
z
0
0
−
Φ
,
t
0
−
Φ
,
z
0
−
Φ
,
x
0
0
−
Φ
,
z
−
Φ
,
y
Φ
,
t
Φ
,
x
Φ
,
y
−
Φ
,
z
]
]
a
↓
[
b
↓
c
→
]
g
u
v
=
[
−
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
u
↓
v
→
g
u
v
=
[
−
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
u
↓
v
→
let
Φ
,
t
=
0
to find:
Γ
a
b
c
=
[
[
0
−
Φ
,
x
−
Φ
,
y
−
Φ
,
z
Φ
,
x
0
0
0
Φ
,
y
0
0
0
Φ
,
z
0
0
0
]
[
−
Φ
,
x
0
0
0
0
−
Φ
,
x
Φ
,
y
Φ
,
z
0
−
Φ
,
y
−
Φ
,
x
0
0
−
Φ
,
z
0
−
Φ
,
x
]
[
−
Φ
,
y
0
0
0
0
−
Φ
,
y
−
Φ
,
x
0
0
Φ
,
x
−
Φ
,
y
Φ
,
z
0
0
−
Φ
,
z
−
Φ
,
y
]
[
−
Φ
,
z
0
0
0
0
−
Φ
,
z
0
−
Φ
,
x
0
0
−
Φ
,
z
−
Φ
,
y
0
Φ
,
x
Φ
,
y
−
Φ
,
z
]
]
a
↓
[
b
↓
c
→
]
let
u
a
=
[
u
t
u
x
u
y
u
z
]
a
↓
matter stress-energy tensor:
T
a
b
=
(
ρ
+
P
)
u
a
u
b
+
P
g
a
b
T
a
b
=
(
ρ
+
P
)
[
u
t
u
x
u
y
u
z
]
a
↓
[
u
t
u
x
u
y
u
z
]
b
↓
+
P
[
−
1
0
0
0
0
1
0
0
0
0
1
0
0
0
0
1
]
a
↓
b
→
T
a
b
=
[
−
P
+
P
u
t
2
+
ρ
⋅
u
t
2
u
t
⋅
u
x
⋅
(
P
+
ρ
)
u
t
⋅
u
y
⋅
(
P
+
ρ
)
u
t
⋅
u
z
⋅
(
P
+
ρ
)
u
t
⋅
u
x
⋅
(
P
+
ρ
)
P
+
P
u
x
2
+
ρ
⋅
u
x
2
u
x
⋅
u
y
⋅
(
P
+
ρ
)
u
x
⋅
u
z
⋅
(
P
+
ρ
)
u
t
⋅
u
y
⋅
(
P
+
ρ
)
u
x
⋅
u
y
⋅
(
P
+
ρ
)
P
+
P
u
y
2
+
ρ
⋅
u
y
2
u
y
⋅
u
z
⋅
(
P
+
ρ
)
u
t
⋅
u
z
⋅
(
P
+
ρ
)
u
x
⋅
u
z
⋅
(
P
+
ρ
)
u
y
⋅
u
z
⋅
(
P
+
ρ
)
P
+
P
u
z
2
+
ρ
⋅
u
z
2
]
a
↓
b
→
∇
⋅
T
=
0
−
P
,
t
+
u
t
2
P
,
t
+
u
t
2
ρ
,
t
+
P
u
t
⋅
u
x
,
x
+
P
u
t
⋅
u
y
,
y
+
P
u
t
⋅
u
z
,
z
+
P
u
x
⋅
u
t
,
x
+
P
u
y
⋅
u
t
,
y
+
P
u
z
⋅
u
t
,
z
+
ρ
⋅
u
t
⋅
u
x
,
x
+
ρ
⋅
u
t
⋅
u
y
,
y
+
ρ
⋅
u
t
⋅
u
z
,
z
+
ρ
⋅
u
x
⋅
u
t
,
x
+
ρ
⋅
u
y
⋅
u
t
,
y
+
ρ
⋅
u
z
⋅
u
t
,
z
+
u
t
⋅
u
x
⋅
P
,
x
+
u
t
⋅
u
x
⋅
ρ
,
x
+
u
t
⋅
u
y
⋅
P
,
y
+
u
t
⋅
u
y
⋅
ρ
,
y
+
u
t
⋅
u
z
⋅
P
,
z
+
u
t
⋅
u
z
⋅
ρ
,
z
+
2
P
u
t
⋅
u
t
,
t
+
2
ρ
⋅
u
t
⋅
u
t
,
t
−
2
P
u
t
⋅
u
x
⋅
Φ
,
x
−
2
P
u
t
⋅
u
y
⋅
Φ
,
y
−
2
P
u
t
⋅
u
z
⋅
Φ
,
z
−
2
ρ
⋅
u
t
⋅
u
x
⋅
Φ
,
x
−
2
ρ
⋅
u
t
⋅
u
y
⋅
Φ
,
y
−
2
ρ
⋅
u
t
⋅
u
z
⋅
Φ
,
z
=
0
P
,
x
+
u
x
2
P
,
x
+
u
x
2
ρ
,
x
+
P
u
t
⋅
u
x
,
t
+
P
u
x
⋅
u
t
,
t
+
P
u
x
⋅
u
y
,
y
+
P
u
x
⋅
u
z
,
z
+
P
u
y
⋅
u
x
,
y
+
P
u
z
⋅
u
x
,
z
−
P
u
t
2
Φ
,
x
−
P
u
y
2
Φ
,
x
−
P
u
z
2
Φ
,
x
+
ρ
⋅
u
t
⋅
u
x
,
t
+
ρ
⋅
u
x
⋅
u
t
,
t
+
ρ
⋅
u
x
⋅
u
y
,
y
+
ρ
⋅
u
x
⋅
u
z
,
z
+
ρ
⋅
u
y
⋅
u
x
,
y
+
ρ
⋅
u
z
⋅
u
x
,
z
−
ρ
⋅
u
t
2
Φ
,
x
−
ρ
⋅
u
y
2
Φ
,
x
−
ρ
⋅
u
z
2
Φ
,
x
+
u
t
⋅
u
x
⋅
P
,
t
+
u
t
⋅
u
x
⋅
ρ
,
t
+
u
x
⋅
u
y
⋅
P
,
y
+
u
x
⋅
u
y
⋅
ρ
,
y
+
u
x
⋅
u
z
⋅
P
,
z
+
u
x
⋅
u
z
⋅
ρ
,
z
−
4
P
Φ
,
x
+
2
P
u
x
⋅
u
x
,
x
+
2
ρ
⋅
u
x
⋅
u
x
,
x
−
3
P
u
x
2
Φ
,
x
−
3
ρ
⋅
u
x
2
Φ
,
x
−
2
P
u
x
⋅
u
y
⋅
Φ
,
y
−
2
P
u
x
⋅
u
z
⋅
Φ
,
z
−
2
ρ
⋅
u
x
⋅
u
y
⋅
Φ
,
y
−
2
ρ
⋅
u
x
⋅
u
z
⋅
Φ
,
z
=
0
P
,
y
+
u
y
2
P
,
y
+
u
y
2
ρ
,
y
+
P
u
t
⋅
u
y
,
t
+
P
u
x
⋅
u
y
,
x
+
P
u
y
⋅
u
t
,
t
+
P
u
y
⋅
u
x
,
x
+
P
u
y
⋅
u
z
,
z
+
P
u
z
⋅
u
y
,
z
−
P
u
t
2
Φ
,
y
−
P
u
x
2
Φ
,
y
−
P
u
z
2
Φ
,
y
+
ρ
⋅
u
t
⋅
u
y
,
t
+
ρ
⋅
u
x
⋅
u
y
,
x
+
ρ
⋅
u
y
⋅
u
t
,
t
+
ρ
⋅
u
y
⋅
u
x
,
x
+
ρ
⋅
u
y
⋅
u
z
,
z
+
ρ
⋅
u
z
⋅
u
y
,
z
−
ρ
⋅
u
t
2
Φ
,
y
−
ρ
⋅
u
x
2
Φ
,
y
−
ρ
⋅
u
z
2
Φ
,
y
+
u
t
⋅
u
y
⋅
P
,
t
+
u
t
⋅
u
y
⋅
ρ
,
t
+
u
x
⋅
u
y
⋅
P
,
x
+
u
x
⋅
u
y
⋅
ρ
,
x
+
u
y
⋅
u
z
⋅
P
,
z
+
u
y
⋅
u
z
⋅
ρ
,
z
−
4
P
Φ
,
y
+
2
P
u
y
⋅
u
y
,
y
+
2
ρ
⋅
u
y
⋅
u
y
,
y
−
3
P
u
y
2
Φ
,
y
−
3
ρ
⋅
u
y
2
Φ
,
y
−
2
P
u
x
⋅
u
y
⋅
Φ
,
x
−
2
P
u
y
⋅
u
z
⋅
Φ
,
z
−
2
ρ
⋅
u
x
⋅
u
y
⋅
Φ
,
x
−
2
ρ
⋅
u
y
⋅
u
z
⋅
Φ
,
z
=
0
P
,
z
+
u
z
2
P
,
z
+
u
z
2
ρ
,
z
+
P
u
t
⋅
u
z
,
t
+
P
u
x
⋅
u
z
,
x
+
P
u
y
⋅
u
z
,
y
+
P
u
z
⋅
u
t
,
t
+
P
u
z
⋅
u
x
,
x
+
P
u
z
⋅
u
y
,
y
−
P
u
t
2
Φ
,
z
−
P
u
x
2
Φ
,
z
−
P
u
y
2
Φ
,
z
+
ρ
⋅
u
t
⋅
u
z
,
t
+
ρ
⋅
u
x
⋅
u
z
,
x
+
ρ
⋅
u
y
⋅
u
z
,
y
+
ρ
⋅
u
z
⋅
u
t
,
t
+
ρ
⋅
u
z
⋅
u
x
,
x
+
ρ
⋅
u
z
⋅
u
y
,
y
−
ρ
⋅
u
t
2
Φ
,
z
−
ρ
⋅
u
x
2
Φ
,
z
−
ρ
⋅
u
y
2
Φ
,
z
+
u
t
⋅
u
z
⋅
P
,
t
+
u
t
⋅
u
z
⋅
ρ
,
t
+
u
x
⋅
u
z
⋅
P
,
x
+
u
x
⋅
u
z
⋅
ρ
,
x
+
u
y
⋅
u
z
⋅
P
,
y
+
u
y
⋅
u
z
⋅
ρ
,
y
−
4
P
Φ
,
z
+
2
P
u
z
⋅
u
z
,
z
+
2
ρ
⋅
u
z
⋅
u
z
,
z
−
3
P
u
z
2
Φ
,
z
−
3
ρ
⋅
u
z
2
Φ
,
z
−
2
P
u
x
⋅
u
z
⋅
Φ
,
x
−
2
P
u
y
⋅
u
z
⋅
Φ
,
y
−
2
ρ
⋅
u
x
⋅
u
z
⋅
Φ
,
x
−
2
ρ
⋅
u
y
⋅
u
z
⋅
Φ
,
y
=
0
low velocity relativistic approximations:
u
t
=
1
∇
⋅
T
=
0
becomes:
ρ
,
t
+
P
u
x
,
x
+
P
u
y
,
y
+
P
u
z
,
z
+
ρ
⋅
u
x
,
x
+
ρ
⋅
u
y
,
y
+
ρ
⋅
u
z
,
z
+
u
x
⋅
P
,
x
+
u
x
⋅
ρ
,
x
+
u
y
⋅
P
,
y
+
u
y
⋅
ρ
,
y
+
u
z
⋅
P
,
z
+
u
z
⋅
ρ
,
z
−
2
P
u
x
⋅
Φ
,
x
−
2
P
u
y
⋅
Φ
,
y
−
2
P
u
z
⋅
Φ
,
z
−
2
ρ
⋅
u
x
⋅
Φ
,
x
−
2
ρ
⋅
u
y
⋅
Φ
,
y
−
2
ρ
⋅
u
z
⋅
Φ
,
z
=
0
P
,
x
+
P
u
x
,
t
+
ρ
⋅
u
x
,
t
−
ρ
⋅
Φ
,
x
+
u
x
⋅
P
,
t
+
u
x
⋅
ρ
,
t
+
u
x
2
P
,
x
+
u
x
2
ρ
,
x
−
5
P
Φ
,
x
+
P
u
x
⋅
u
y
,
y
+
P
u
x
⋅
u
z
,
z
+
P
u
y
⋅
u
x
,
y
+
P
u
z
⋅
u
x
,
z
−
P
u
y
2
Φ
,
x
−
P
u
z
2
Φ
,
x
+
ρ
⋅
u
x
⋅
u
y
,
y
+
ρ
⋅
u
x
⋅
u
z
,
z
+
ρ
⋅
u
y
⋅
u
x
,
y
+
ρ
⋅
u
z
⋅
u
x
,
z
−
ρ
⋅
u
y
2
Φ
,
x
−
ρ
⋅
u
z
2
Φ
,
x
+
u
x
⋅
u
y
⋅
P
,
y
+
u
x
⋅
u
y
⋅
ρ
,
y
+
u
x
⋅
u
z
⋅
P
,
z
+
u
x
⋅
u
z
⋅
ρ
,
z
+
2
P
u
x
⋅
u
x
,
x
+
2
ρ
⋅
u
x
⋅
u
x
,
x
−
3
P
u
x
2
Φ
,
x
−
3
ρ
⋅
u
x
2
Φ
,
x
−
2
P
u
x
⋅
u
y
⋅
Φ
,
y
−
2
P
u
x
⋅
u
z
⋅
Φ
,
z
−
2
ρ
⋅
u
x
⋅
u
y
⋅
Φ
,
y
−
2
ρ
⋅
u
x
⋅
u
z
⋅
Φ
,
z
=
0
P
,
y
+
P
u
y
,
t
+
ρ
⋅
u
y
,
t
−
ρ
⋅
Φ
,
y
+
u
y
⋅
P
,
t
+
u
y
⋅
ρ
,
t
+
u
y
2
P
,
y
+
u
y
2
ρ
,
y
−
5
P
Φ
,
y
+
P
u
x
⋅
u
y
,
x
+
P
u
y
⋅
u
x
,
x
+
P
u
y
⋅
u
z
,
z
+
P
u
z
⋅
u
y
,
z
−
P
u
x
2
Φ
,
y
−
P
u
z
2
Φ
,
y
+
ρ
⋅
u
x
⋅
u
y
,
x
+
ρ
⋅
u
y
⋅
u
x
,
x
+
ρ
⋅
u
y
⋅
u
z
,
z
+
ρ
⋅
u
z
⋅
u
y
,
z
−
ρ
⋅
u
x
2
Φ
,
y
−
ρ
⋅
u
z
2
Φ
,
y
+
u
x
⋅
u
y
⋅
P
,
x
+
u
x
⋅
u
y
⋅
ρ
,
x
+
u
y
⋅
u
z
⋅
P
,
z
+
u
y
⋅
u
z
⋅
ρ
,
z
+
2
P
u
y
⋅
u
y
,
y
+
2
ρ
⋅
u
y
⋅
u
y
,
y
−
3
P
u
y
2
Φ
,
y
−
3
ρ
⋅
u
y
2
Φ
,
y
−
2
P
u
x
⋅
u
y
⋅
Φ
,
x
−
2
P
u
y
⋅
u
z
⋅
Φ
,
z
−
2
ρ
⋅
u
x
⋅
u
y
⋅
Φ
,
x
−
2
ρ
⋅
u
y
⋅
u
z
⋅
Φ
,
z
=
0
P
,
z
+
P
u
z
,
t
+
ρ
⋅
u
z
,
t
−
ρ
⋅
Φ
,
z
+
u
z
⋅
P
,
t
+
u
z
⋅
ρ
,
t
+
u
z
2
P
,
z
+
u
z
2
ρ
,
z
−
5
P
Φ
,
z
+
P
u
x
⋅
u
z
,
x
+
P
u
y
⋅
u
z
,
y
+
P
u
z
⋅
u
x
,
x
+
P
u
z
⋅
u
y
,
y
−
P
u
x
2
Φ
,
z
−
P
u
y
2
Φ
,
z
+
ρ
⋅
u
x
⋅
u
z
,
x
+
ρ
⋅
u
y
⋅
u
z
,
y
+
ρ
⋅
u
z
⋅
u
x
,
x
+
ρ
⋅
u
z
⋅
u
y
,
y
−
ρ
⋅
u
x
2
Φ
,
z
−
ρ
⋅
u
y
2
Φ
,
z
+
u
x
⋅
u
z
⋅
P
,
x
+
u
x
⋅
u
z
⋅
ρ
,
x
+
u
y
⋅
u
z
⋅
P
,
y
+
u
y
⋅
u
z
⋅
ρ
,
y
+
2
P
u
z
⋅
u
z
,
z
+
2
ρ
⋅
u
z
⋅
u
z
,
z
−
3
P
u
z
2
Φ
,
z
−
3
ρ
⋅
u
z
2
Φ
,
z
−
2
P
u
x
⋅
u
z
⋅
Φ
,
x
−
2
P
u
y
⋅
u
z
⋅
Φ
,
y
−
2
ρ
⋅
u
x
⋅
u
z
⋅
Φ
,
x
−
2
ρ
⋅
u
y
⋅
u
z
⋅
Φ
,
y
=
0
P
u
x
,
x
+
P
u
y
,
y
+
P
u
z
,
z
+
u
x
⋅
P
,
x
+
u
y
⋅
P
,
y
+
u
z
⋅
P
,
z
=
0
first equation in terms of
∂
t
ρ
ρ
,
t
=
−
ρ
⋅
u
x
,
x
−
ρ
⋅
u
y
,
y
−
ρ
⋅
u
z
,
z
−
u
x
⋅
ρ
,
x
−
u
y
⋅
ρ
,
y
−
u
z
⋅
ρ
,
z
+
2
P
u
x
⋅
Φ
,
x
+
2
P
u
y
⋅
Φ
,
y
+
2
P
u
z
⋅
Φ
,
z
+
2
ρ
⋅
u
x
⋅
Φ
,
x
+
2
ρ
⋅
u
y
⋅
Φ
,
y
+
2
ρ
⋅
u
z
⋅
Φ
,
z
spatial equations neglect
P
,
t
,
(
P
u
j
)
,
j
,
P
, and
Φ
,
i
u
j
and substitutes the definition of
∂
t
ρ
∇
⋅
T
=
0
becomes:
ρ
,
t
+
ρ
⋅
u
x
,
x
+
ρ
⋅
u
y
,
y
+
ρ
⋅
u
z
,
z
+
u
x
⋅
ρ
,
x
+
u
y
⋅
ρ
,
y
+
u
z
⋅
ρ
,
z
−
2
P
u
x
⋅
Φ
,
x
−
2
P
u
y
⋅
Φ
,
y
−
2
P
u
z
⋅
Φ
,
z
−
2
ρ
⋅
u
x
⋅
Φ
,
x
−
2
ρ
⋅
u
y
⋅
Φ
,
y
−
2
ρ
⋅
u
z
⋅
Φ
,
z
=
0
P
,
x
+
ρ
⋅
u
x
,
t
−
ρ
⋅
Φ
,
x
+
ρ
⋅
u
x
⋅
u
x
,
x
+
ρ
⋅
u
y
⋅
u
x
,
y
+
ρ
⋅
u
z
⋅
u
x
,
z
=
0
P
,
y
+
ρ
⋅
u
y
,
t
−
ρ
⋅
Φ
,
y
+
ρ
⋅
u
x
⋅
u
y
,
x
+
ρ
⋅
u
y
⋅
u
y
,
y
+
ρ
⋅
u
z
⋅
u
y
,
z
=
0
P
,
z
+
ρ
⋅
u
z
,
t
−
ρ
⋅
Φ
,
z
+
ρ
⋅
u
x
⋅
u
z
,
x
+
ρ
⋅
u
y
⋅
u
z
,
y
+
ρ
⋅
u
z
⋅
u
z
,
z
=
0