atmCoriolisUSource

- The
`atmCoriolisUSource`

applies corrections to incorporate the horizontal and vertical components of the Coriolis force for which the rotating frame is Earth. - The Coriolis force is an inertial or fictitious force that acts on objects that are in motion within a frame of reference that rotates with respect to an inertial frame.
- In the atmospheric boundary layer context, for the "Coriolis effect", the rotating reference frame implied is almost always Earth. Because Earth spins, Earth-bound observers need to account for the Coriolis force to correctly analyze the motion of objects. Earth completes one rotation per day, so for motions of everyday objects the Coriolis force is usually quite small compared with other forces; its effects generally become noticeable only for motions occurring over large distances and long periods of time, such as large-scale movement of air in the atmosphere or water in the ocean. Such motions are constrained by the surface of Earth, so only the horizontal component of the Coriolis force is generally important.
- The
`atmCoriolisUSource`

can be applied on any RAS turbulence model. - The
`atmCoriolisUSource`

inherits the traits of the fvOption, and`cellSetOption`

.

Corrections applied on:

U | Velocity [m/s]

Required fields:

U | Velocity [m/s]

The model expression:

\[ f_M -= \alpha \rho ((2 \Omega) \times \u ) \]

where

\( f_M \) | = | fvMatrix of the velocity field |

\( \Omega \) | = | Rotation vector of the rotating reference frame relative to the inertial frame [rad/s] |

\( \u \) | = | Velocity field [m/s] |

\( \alpha \) | = | Phase fraction in multiphase computations, otherwise equals to 1 |

\( \rho \) | = | Fluid density in compressible computations, otherwise equals to 1 |

Example of the fvOptions specification using `constant/fvOptions`

file:

atmCoriolisUSource1 { // Mandatory entries (unmodifiable) type atmCoriolisUSource; atmCoriolisUSourceCoeffs { // Mandatory (inherited) entries (unmodifiable) selectionMode all; // Conditional mandatory entries (unmodifiable) // Select either of the below // Option-1: to directly input rotation vector Omega (0 0 5.65156e-5); // Option-2: to indirectly input rotation vector // by a latitude-period pair latitude 51.971; planetaryRotationPeriod 23.9344694; } // Optional (inherited) entries ... }

where the entries mean:

Property | Description | Type | Required | Default |
---|---|---|---|---|

type | Type name: atmCoriolisUSource | word | yes | - |

latitude | Geographic coordinate specifying the northâ€“south position of a point on the surface of a planetary body [degree] | scalar | conditional | 0.0 |

planetaryRotationPeriod | Rotation period of the planetary body [h] | scalar | conditional | 23.9344694 |

Omega | Rotation vector of the rotating reference frame relative to the inertial frame [rad/s] | vector | conditional | (0 0 0) |

The inherited entries are elaborated in:

- fvOption
`cellSetOption`

Tutorials

- $FOAM_TUTORIALS/verificationAndValidation/atmosphericModels/atmFlatTerrain
- $FOAM_TUTORIALS/verificationAndValidation/atmosphericModels/atmForestStability

Source code

History

- Introduced in version v2006