The particle characteristics in LPT

Are the particles taken as mass points in ee? What their characteristics are? The description of the particle characteristics in LPT in EE is not specific. I can’t find detailed imformation in the User Manual or the EFDC_DS_Lagrangian_Particle_Tracking(2009_08_27). In the options window, the Fully 3D Lagrangian Neutrally Buoyant particles can be chosen in the vertical movement. I really wish to know some more spcific information about the particle characteristics and their significance to the practical issues.

Hi Jamesyangsy,

The Lagrangian particles used in EFDC_DSI have zero mass associated to them. You could however specify the settling velocity to the particles if desired. A particle is said to be Lagrangian when it moves as though it is an element of fluid. The particle may be thought of as the location of the center of mass of the fluid element. There are no connections between particles so they are free to move and follow the dynamics of a flow regardless of its complexity.

In EFDC_DSI, the Lagrangian coordinates of the particles are calculated from the Eulerian coordinates. Lagrangian particles do not carry mass but are simply used as markers to define grid regions occupied by fluid.

EFDC_DSI also has oil spill capability where it employs Lagrangian particle tracking method where user needs to specify oil density, total volume of oil, biodegradation rate, vapor pressure etc.

I hope it helps.

Janesh Devkota