fdtd-coremem/examples/wrapped_torus.rs

use coremem::{Driver, Flt, mat, meas};
use coremem::geom::{Index, Meters, Torus};
use coremem::stim::{CurlStimulus, Sinusoid1, TimeVarying1 as _};

fn main() {
    coremem::init_logging();
    let feat_size = 10e-6f32; // feature size
    let duration = 0.5e-9;
    let width = 4800e-6;
    let height = 2200e-6;
    let depth = 1800e-6;
    let buffer = 200e-6;
    let ferro_major = 320e-6;
    let ferro_minor = 60e-6;
    let wire_minor = 40e-6;
    let wire_major = 160e-6;
    let peak_current = 5e6;
    let current_duration = 0.1e-9; // half-wavelength of the sine wave
    let current_break = 0.1e-9; // time between 'set' pulse and 'clear' pulse
    let drive_conductivity = 5.0f32;
    let sense_conductivity = 5.0f32;

    let from_m = |m: f32| (m/feat_size).round() as u32;
    let m_to_um = |m: f32| (m * 1e6).round() as u32;
    let half_width = width * 0.5;
    let q1_width = width * 0.25;
    let q3_width = width * 0.75;
    let half_height = height * 0.5;
    let half_depth = depth * 0.5;

    let width_px = from_m(width);
    let height_px = from_m(height);
    let depth_px = from_m(depth);
    let size_px = Index((width_px, height_px, depth_px).into());
    let mut driver: Driver<mat::GenericMaterial> = Driver::new(size_px, feat_size);
    driver.set_steps_per_frame(500);
    // driver.set_steps_per_stim(10);
    let base = "wrapped_torus-21-high-input-resistance";

    let ferro1_region = Torus::new_xy(Meters::new(q1_width, half_height, half_depth), ferro_major, ferro_minor);
    let drive1_region = Torus::new_xz(Meters::new(q1_width - ferro_major, half_height, half_depth), wire_major, wire_minor);
    let sense1_region = Torus::new_xz(Meters::new(q1_width + ferro_major, half_height, half_depth), wire_major, wire_minor);

    driver.fill_region(&ferro1_region, mat::db::linear_iron().into());
    driver.fill_region(&drive1_region, mat::db::conductor(drive_conductivity as _).into());
    driver.fill_region(&sense1_region, mat::db::conductor(sense_conductivity as _).into());

    let ferro2_region = Torus::new_xy(Meters::new(q3_width, half_height, half_depth), ferro_major, ferro_minor);
    let drive2_region = Torus::new_xz(Meters::new(q3_width - ferro_major, half_height, half_depth), wire_major, wire_minor);
    let sense2_region = Torus::new_xz(Meters::new(q3_width + ferro_major, half_height, half_depth), wire_major, wire_minor);

    driver.fill_region(&ferro2_region, mat::db::ferroxcube_3r1().into());
    driver.fill_region(&drive2_region, mat::db::conductor(drive_conductivity as _).into());
    driver.fill_region(&sense2_region, mat::db::conductor(sense_conductivity as _).into());

    let boundary_xy = q1_width - ferro_major - ferro_minor - buffer;
    let boundary_z = half_depth - wire_major - wire_minor - buffer;
    println!("boundary: {}um; {}um", m_to_um(boundary_xy), m_to_um(boundary_z));
    driver.add_pml_boundary(Meters::new(boundary_xy, boundary_xy, boundary_z));

    // J=\sigma E
    // dJ/dt = \sigma dE/dT
    // dE/dt = dJ/dt / \sigma
    // dE/dt = dI/dt / (A*\sigma)
    // if I = k*sin(w t) then dE/dt = k*w sin(w t) / (A*\sigma)
    // i.e. dE/dt is proportional to I/(A*\sigma), multiplied by w (or, divided by wavelength)
    let peak_stim = peak_current/current_duration / (drive1_region.cross_section() * drive_conductivity);
    let pos_wave = Sinusoid1::from_wavelength(peak_stim, current_duration * 2.0)
        .half_cycle();

    let neg_wave = Sinusoid1::from_wavelength(-4.0*peak_stim, current_duration * 2.0)
        .half_cycle()
        .shifted(current_duration + current_break);

    driver.add_stimulus(CurlStimulus::new(
        drive1_region.clone(),
        pos_wave.clone(),
        drive1_region.center(),
        drive1_region.axis()
    ));
    driver.add_stimulus(CurlStimulus::new(
        drive1_region.clone(),
        neg_wave.clone(),
        drive1_region.center(),
        drive1_region.axis()
    ));

    driver.add_stimulus(CurlStimulus::new(
        drive2_region.clone(),
        pos_wave,
        drive2_region.center(),
        drive2_region.axis()
    ));
    driver.add_stimulus(CurlStimulus::new(
        drive2_region.clone(),
        neg_wave,
        drive2_region.center(),
        drive2_region.axis()
    ));

    driver.add_measurement(meas::CurrentLoop::new("sense1", sense1_region.clone()));
    driver.add_measurement(meas::Current::new("sense1", sense1_region.clone()));
    driver.add_measurement(meas::MagneticLoop::new("mem1", ferro1_region.clone()));
    driver.add_measurement(meas::Magnetization::new("mem1", ferro1_region.clone()));
    driver.add_measurement(meas::MagneticFlux::new("mem1", ferro1_region.clone()));
    driver.add_measurement(meas::CurrentLoop::new("drive1", drive1_region.clone()));
    driver.add_measurement(meas::Current::new("drive1", drive1_region.clone()));
    driver.add_measurement(meas::Power::new("drive1", drive1_region.clone()));

    driver.add_measurement(meas::CurrentLoop::new("sense2", sense2_region.clone()));
    driver.add_measurement(meas::Current::new("sense2", sense2_region.clone()));
    driver.add_measurement(meas::MagneticLoop::new("mem2", ferro2_region.clone()));
    driver.add_measurement(meas::Magnetization::new("mem2", ferro2_region.clone()));
    driver.add_measurement(meas::MagneticFlux::new("mem2", ferro2_region.clone()));
    driver.add_measurement(meas::CurrentLoop::new("drive2", drive2_region.clone()));
    driver.add_measurement(meas::Current::new("drive2", drive2_region.clone()));
    driver.add_measurement(meas::Power::new("drive2", drive2_region.clone()));

    let prefix = format!("out/{}/{}-flt{}-{}-feat{}um-{}mA-{}ps--radii{}um-{}um-{}um-{}um",
        base,
        base,
        std::mem::size_of::<Flt>() * 8,
        *size_px,
        m_to_um(feat_size),
        (peak_current * 1e3).round() as i64,
        (current_duration * 1e12).round() as i64,
        m_to_um(ferro_major),
        m_to_um(ferro_minor),
        m_to_um(wire_major),
        m_to_um(wire_minor),
    );
    let _ = std::fs::create_dir_all(&prefix);

    driver.add_serializer_renderer(&*format!("{}/frame-", prefix));

    driver.step_until(duration);
}