//! Benchmarks for the evaluation of the first derivative of the

//! Helmholtz energy function for various binary mixtures.

//! The mixtures contain fluids of different polarities that are

//! modeled using additional Helmholtz energy contributions.

//! It is supposed to demonstrate the expected reduction in

//! performance when more complex physical interactions are

//! modeled.

use ::num_dual::Dual64;

use criterion::{Criterion, criterion_group, criterion_main};

use feos::core::parameter::IdentifierOption;

use feos::core::{DensityInitialization, Residual, State};

use feos::pcsaft::{PcSaft, PcSaftAssociationRecord, PcSaftParameters, PcSaftRecord};

use feos_core::ReferenceSystem;

use feos_core::parameter::PureRecord;

use nalgebra::dvector;

use num_dual::Dual;

use quantity::*;

type Pure = PureRecord<PcSaftRecord, PcSaftAssociationRecord>;

/// Benchmark for the PC-SAFT equation of state

fn pcsaft(c: &mut Criterion) {

let mut group = c.benchmark_group("pcsaft");

// non-polar components

let mut records = Pure::from_json(

&["hexane", "heptane"],

"../../parameters/pcsaft/gross2001.json",

IdentifierOption::Name,

)

.unwrap();

let hexane = records.remove(0);

let heptane = records.remove(0);

// dipolar components

records = Pure::from_json(

&["acetone", "dimethyl ether"],

"../../parameters/pcsaft/gross2006.json",

IdentifierOption::Name,

)

.unwrap();

let acetone = records.remove(0);

let dme = records.remove(0);

// quadrupolar components

records = Pure::from_json(

&["carbon dioxide", "acetylene"],

"../../parameters/pcsaft/gross2005_literature.json",

IdentifierOption::Name,

)

.unwrap();

let co2 = records.remove(0);

let acetylene = records.remove(0);

// associating components

records = Pure::from_json(

&["ethanol", "1-propanol"],

"../../parameters/pcsaft/gross2002.json",

IdentifierOption::Name,

)

.unwrap();

let ethanol = records.remove(0);

let propanol = records.remove(0);

let t = 300.0 * KELVIN;

let p = BAR;

let moles = dvector![1.0, 1.0] * MOL;

for comp1 in &[hexane, acetone, co2, ethanol] {

for comp2 in [&heptane, &dme, &acetylene, &propanol] {

let params =

PcSaftParameters::new_binary([comp1.clone(), comp2.clone()], None, vec![]).unwrap();

let eos = PcSaft::new(params);

let state =

State::new_npt(&&eos, t, p, &moles, Some(DensityInitialization::Liquid)).unwrap();

let temperature = Dual64::from(state.temperature.into_reduced()).derivative();

let molar_volume = Dual::from(1.0 / state.density.into_reduced());

let moles = state.moles().unwrap().to_reduced().map(Dual::from);

// let state_hd = state.derive1(Derivative::DT);

let name1 = comp1.identifier.name.as_deref().unwrap();

let name2 = comp2.identifier.name.as_deref().unwrap();

let mix = format!("{name1}_{name2}");

group.bench_function(mix, |b| {

b.iter(|| (&eos).residual_helmholtz_energy(temperature, molar_volume, &moles))

});

}

}

}

criterion_group!(bench, pcsaft);

criterion_main!(bench);