CustomVelocity.H

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#ifndef CUSTOM_VELOCITY_H
#define CUSTOM_VELOCITY_H
 
#include "AMReX_Geometry.H"
#include "AMReX_Gpu.H"
 
namespace amr_wind {
 
class Field;
 
namespace udf {
 
struct CustomVelocity
{
    struct DeviceOp
    {
        // Declare parameters here if needed. For example:
        amrex::Real foo{1.0};
        amrex::GpuArray<amrex::Real, AMREX_SPACEDIM> bar = {0.0};
 
        AMREX_GPU_DEVICE
        inline void operator()(
            const amrex::IntVect& iv,
            amrex::Array4<amrex::Real> const& field,
            amrex::GeometryData const& geom,
            const amrex::Real /*time*/,
            amrex::Orientation /*ori*/,
            const int comp,
            const int dcomp,
            const int orig_comp) const
        {
            // Compute quantities to set the field values. For example:
            const auto* problo = geom.ProbLo();
            const auto* dx = geom.CellSize();
            const auto x = problo[0] + (iv[0] + 0.5) * dx[0];
            const auto y = problo[1] + (iv[1] + 0.5) * dx[1];
            const auto z = problo[2] + (iv[2] + 0.5) * dx[2];
            const amrex::GpuArray<amrex::Real, AMREX_SPACEDIM> vel = {
                1.0, 0.0, 0.0};
 
            // Once the above is done, fill the field as:
            field(iv[0], iv[1], iv[2], dcomp + comp) = vel[orig_comp + comp];
            amrex::ignore_unused(x, y, z);
        }
        inline void operator()( {…}
    };
    struct DeviceOp {…};
    using DeviceType = DeviceOp;
 
    static std::string identifier() { return "CustomVelocity"; }
 
    explicit CustomVelocity(const Field& fld);
 
    DeviceType device_instance() const { return m_op; }
 
    DeviceOp m_op;
};
struct CustomVelocity {…};
 
} // namespace udf
} // namespace amr_wind
 
#endif /* CUSTOM_VELOCITY_H */