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DEL IN CYLINDRICAL AND SPHERICAL COORDINATES

This is a list of some vector calculus formulae of general use in working with standard coordinate systems.








Table with the del operator in cylindrical and spherical coordinates
Operation
Cartesian coordinates (x,y,z)
Cylindrical coordinates (ρ,φ,z)
Spherical coordinates (r,θ,φ)
Definition
of
coordinates
 
left[egin{matrix}
x & = &
hocosphi \
y & = &
hosinphi \
z & = & z end{matrix}
ight].
left[egin{matrix}
x & = & rsin hetacosphi \
y & = & rsin hetasinphi \
z & = & rcos heta end{matrix}
ight].
left[egin{matrix}

ho & = & sqrt{x^2 + y^2} \
phi & = & rctan{(y/x)}\
z & = & z end{matrix}
ight].
left[egin{matrix}
r & = & sqrt{x^2 + y^2 + z^2} \
heta & = & rccos(z / r) = rctan{(sqrt{x^2+y^2}/z)}\
phi & = & rctan{(y/x)} end{matrix}
ight].
A vector field mathbf{A}
A_xmathbf{hat x} + A_ymathbf{hat y} + A_zmathbf{hat z}
A_
hooldsymbol{hat
ho} + A_phioldsymbol{hat phi} + A_zoldsymbol{hat z}
A_roldsymbol{hat r} + A_ hetaoldsymbol{hat heta} + A_phioldsymbol{hat phi}
Gradient
abla f
{partial f over partial x}mathbf{hat x} + {partial f over partial y}mathbf{hat y}
+ {partial f over partial z}mathbf{hat z}
{partial f over partial
ho}oldsymbol{hat
ho}
+ {1 over
ho}{partial f over partial phi}oldsymbol{hat phi}
+ {partial f over partial z}oldsymbol{hat z}
{partial f over partial r}oldsymbol{hat r}
+ {1 over r}{partial f over partial heta}oldsymbol{hat heta}
+ {1 over rsin heta}{partial f over partial phi}oldsymbol{hat phi}
Divergence
abla cdot mathbf{A}
{partial A_x over partial x} + {partial A_y over partial y} + {partial A_z over partial z}
{1 over
ho}{partial (
ho A_
ho ) over partial
ho}
+ {1 over
ho}{partial A_phi over partial phi}
+ {partial A_z over partial z}
{1 over r^2}{partial ( r^2 A_r ) over partial r}
+ {1 over rsin heta}{partial over partial heta} ( A_ hetasin heta )
+ {1 over rsin heta}{partial A_phi over partial phi}
Curl
abla imes mathbf{A}
egin{matrix}
displaystyle({partial A_z over partial y} - {partial A_y over partial z}) mathbf{hat x} & + \
displaystyle({partial A_x over partial z} - {partial A_z over partial x}) mathbf{hat y} & + \
displaystyle({partial A_y over partial x} - {partial A_x over partial y}) mathbf{hat z} & end{matrix}
egin{matrix}
displaystyle({1 over
ho}{partial A_z over partial phi}
- {partial A_phi over partial z}) oldsymbol{hat
ho} & + \
displaystyle({partial A_
ho over partial z} - {partial A_z over partial
ho}) oldsymbol{hat phi} & + \
displaystyle{1 over
ho}({partial (
ho A_phi ) over partial
ho}
- {partial A_
ho over partial phi}) oldsymbol{hat z} & end{matrix}
egin{matrix}
displaystyle{1 over rsin heta}({partial over partial heta} ( A_phisin heta )
- {partial A_ heta over partial phi}) oldsymbol{hat r} & + \
displaystyle{1 over r}({1 over sin heta}{partial A_r over partial phi}
- {partial over partial r} ( r A_phi ) ) oldsymbol{hat heta} & + \
displaystyle{1 over r}({partial over partial r} ( r A_ heta )
- {partial A_r over partial heta}) oldsymbol{hat phi} & end{matrix}
Laplace operator Delta f =
abla^2 f
{partial^2 f over partial x^2} + {partial^2 f over partial y^2} + {partial^2 f over partial z^2}
{1 over
ho}{partial over partial
ho}(
ho {partial f over partial
ho})
+ {1 over
ho^2}{partial^2 f over partial phi^2}
+ {partial^2 f over partial z^2}
{1 over r^2}{partial over partial r}(r^2 {partial f over partial r})
+ {1 over r^2sin heta}{partial over partial heta}(sin heta {partial f over partial heta})
+ {1 over r^2sin^2 heta}{partial^2 f over partial phi^2}
or
{1 over r}{partial^2 over partial r^2}(r f)
+ {1 over r^2sin heta}{partial over partial heta}(sin heta {partial f over partial heta})
+ {1 over r^2sin^2 heta}{partial^2 f over partial phi^2}
Delta mathbf{A} =
abla^2 mathbf{A}
Delta A_x mathbf{hat x} + Delta A_y mathbf{hat y} + Delta A_z mathbf{hat z}
egin{matrix}
displaystyle(Delta A_
ho - {A_
ho over
ho^2}
- {2 over
ho^2}{partial A_phi over partial phi}) oldsymbol{hat
ho} & + \
displaystyle(Delta A_phi - {A_phi over
ho^2}
+ {2 over
ho^2}{partial A_
ho over partial phi}) oldsymbol{hatphi} & + \
displaystyle(Delta A_z ) oldsymbol{hat z} & end{matrix}
egin{matrix}
(Delta A_r - {2 A_r over r^2}
- {2 over r^2sin heta}{partial (A_ heta sin heta) over partial heta}
- {2 over r^2sin heta}{partial A_phi over partial phi}) oldsymbol{hat r} & + \
(Delta A_ heta - {A_ heta over r^2sin^2 heta}
+ {2 over r^2}{partial A_r over partial heta}
- {2 cos heta over r^2sin^2 heta}{partial A_phi over partial phi}) oldsymbol{hat heta} & + \
(Delta A_phi - {A_phi over r^2sin^2 heta}
+ {2 over r^2sin^2 heta}{partial A_r over partial phi}
+ {2 cos heta over r^2sin^2 heta}{partial A_ heta over partial phi}) oldsymbol{hatphi} & end{matrix}
Differential displacement
dmathbf{l} = dxmathbf{hat x} + dymathbf{hat y} + dzmathbf{hat z}
dmathbf{l} = d
hooldsymbol{hat
ho} +
ho dphioldsymbol{hat phi} + dzoldsymbol{hat z}
dmathbf{l} = drmathbf{hat r} + rd hetaoldsymbol{hat heta} + rsin heta dphioldsymbol{hat phi}
Differential normal area
egin{matrix}dmathbf{S} = &dydzmathbf{hat x} + \
&dxdzmathbf{hat y} + \
&dxdymathbf{hat z}end{matrix}
egin{matrix}
dmathbf{S} = &
ho dphi dzoldsymbol{hat
ho} + \
& d
ho dzoldsymbol{hat phi} + \
&
ho d
ho dphi mathbf{hat z}
end{matrix}
egin{matrix}
dmathbf{S} = & r^2 sin heta d heta dphi mathbf{hat r} + \
& rsin heta drdphi oldsymbol{hat heta} + \
& rdrd hetaoldsymbol{hat phi}
end{matrix}
Differential volume
dv = dxdydz ,
dv =
ho d
ho dphi dz,
dv = r^2sin heta drd heta dphi,
Non-trivial calculation rules:

  1. operatorname{div grad } f =
    abla cdot (
    abla f) =
    abla^2 f = Delta f (Laplacian)
  2. operatorname{curl grad } f =
    abla imes (
    abla f) = 0
  3. operatorname{div curl } mathbf{A} =
    abla cdot (
    abla imes mathbf{A}) = 0
  4. operatorname{curl curl } mathbf{A} =
    abla imes (
    abla imes mathbf{A})
    =
    abla (
    abla cdot mathbf{A}) -
    abla^2 mathbf{A}
  5. Delta f g = f Delta g + 2
    abla f cdot
    abla g + g Delta f
  6. Lagrange's formula for the cross product:

    mathbf{A} imes (mathbf{B} imes mathbf{C})
    = mathbf{B} (mathbf{A} cdot mathbf{C}) - mathbf{C} (mathbf{A} cdot mathbf{B})



Contents
Remarks
See also

Remarks



★ This page uses standard physics notation; some (American mathematics) sources define phi as the angle from the z-axis instead of heta.

★ The function atan2(y, x) is used instead of the mathematical function arctan(y/x) due to its domain and image. The classical arctan(y/x) has an image of (-π/2, +π/2), whereas atan2(y, x) is defined to have an image of (-π, π].

See also



Orthogonal coordinates

Curvilinear coordinates

Vector fields in cylindrical and spherical coordinates

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