Both ABLSolver and ABLTerrainSolver are updated with the ability to add a sponge layer so as to avoid reflection of atmospheric gravity waves at the top of the numerical domain. Both Rayleigh damping and viscous damping are supported. The damping coefficient increases with height as a cosine function. Rayleigh damping takes a reference velocity (constant in space and time) as an input value.
The sponge layer is configure using the following input parameters in "constant/ABLProperties":
// Type of sponge layer: "none" (Default), "Rayleigh" or "viscous".
spongeLayerType "Rayleigh";
// Base height of the sponge layer (m).
spongeLayerBaseHeight 1700.0;
// Top height of the sponge layer (m).
spongeLayerTopHeight 2000.0;
// Sponge layer reference velocity (only for Rayleigh) in x direction (m/s)
spongeLayerUx $U0Mag;
// Sponge layer reference velocity (only for Rayleigh) in y direction (m/s)
spongeLayerUy 0.0;
// Maximum viscosity attained at the top of the sponge layer
// Dimensions depend on type of damping:
// Rayleigh (1/s)
// viscous (m^2/s)
spongeLayerViscosityTop 0.0002;
Both ABLSolver and ABLTerrainSolver are updated with the ability to add a sponge layer so as to avoid reflection of atmospheric gravity waves at the top of the numerical domain. Both Rayleigh damping and viscous damping are supported. The damping coefficient increases with height as a cosine function. Rayleigh damping takes a reference velocity (constant in space and time) as an input value.
The sponge layer is configure using the following input parameters in "constant/ABLProperties": // Type of sponge layer: "none" (Default), "Rayleigh" or "viscous". spongeLayerType "Rayleigh"; // Base height of the sponge layer (m). spongeLayerBaseHeight 1700.0; // Top height of the sponge layer (m). spongeLayerTopHeight 2000.0; // Sponge layer reference velocity (only for Rayleigh) in x direction (m/s) spongeLayerUx $U0Mag; // Sponge layer reference velocity (only for Rayleigh) in y direction (m/s) spongeLayerUy 0.0; // Maximum viscosity attained at the top of the sponge layer // Dimensions depend on type of damping: // Rayleigh (1/s) // viscous (m^2/s) spongeLayerViscosityTop 0.0002;