wave drift and wind force opposite in Moses

Final2.rar

Can anybody help me to explain why I am getting wind, current in one direction but wave drift and other coriolis force in opposite direction. I am using same angle for wind, wave and current.

  • Hello S. Kumar,

    Wave drift force and Coriolis force are two different forces.  Coriolis force is about inertia and how the body rotates.  Below is a link that explain this in better terms.

    https://en.wikipedia.org/wiki/Coriolis_force

    Please have a review.

    Thank you,

    Georgina Maldonado

  • Thanks Georgina for answer.

    In my code i am using same angle for wave, wind and current.....but wave drift load direction is different from wind and current direction.

    At 0 degree environment wave drift, wind load and current load should be positive but, here drift load is -ve while other two are positive.

    Your help is much appreciated.

  • Hello S. Kumar,

    Coriolis force is about inertia and the body moving.  In the wiki page, I linked in the previous communication, the following bullet points summarize the expected values.

    • if the velocity is parallel to the rotation axis, the Coriolis acceleration is zero. (For example, on Earth, this situation occurs for a body on the equator moving north or south relative to Earth's surface.)
    • if the velocity is straight inward to the axis, the acceleration is in the direction of local rotation. (For example, on Earth, this situation occurs for a body on the equator falling downward, as in the Dechales illustration above, where the falling ball travels further to the east than does the tower.)
    • if the velocity is straight outward from the axis, the acceleration is against the direction of local rotation. (In the tower example, a ball launched upward would move toward the west.)
    • if the velocity is in the direction of local rotation, the acceleration is outward from the axis. (For example, on Earth, this situation occurs for a body on the equator moving east relative to Earth's surface. It would move upward as seen by an observer on the surface. This effect (see Eötvös effect below) was discussed by Galileo Galilei in 1632 and by Riccioli in 1651.[21])
    • if the velocity is against the direction of local rotation, the acceleration is inward to the axis. (On Earth, this situation occurs for a body on the equator moving west, which would deflect downward as seen by an observer.)

    Please review the above and respond with why you believe the wave drift force and the Coriolis force should be in the same direction.

    georgina

  • Here my concern is not coriolis force..I am asking when I am using colliner environment for wind wave and current, wind and current is positive but wave drift force is negative...so in all environment heading it's happening. Means if I m choosing 0 degree for sea wind and current option...my wind load,current load and wave drift load should be in same direction..but I am getting wind and current collinear but wave drift in opposite direction. Any help will be highly appreciated as I am novice to Moses. 

  • 0 deg meaning you apply from ship stern. and the surge response shall be in negative. the ship is moving forward i.e. in -X axis.