IF97

IF97 is the high-speed package of IAPWS-IF97 in Rust. It is suitable for computation-intensive calculations，such as heat cycle calculations, simulations of non-stationary processes, real-time process monitoring and optimizations.

Through the high-speed package, the results of the IAPWS-IF97 are accurately produced at about 5-15x speed-up compared to the powi() of the Rust standard library，2-3x speed-up compared to the C implementation using the same fast algorithms.

• The comparison results of the computing-time are obtained using the criterion.rs.

The Fast Algorithm

1. The shortest addition chain computes integer powers of a number.(the paper in chinese)
2. The recursive algorithm computes the polynomial values of the base variable and it's derivatives

In IF97, 35 thermodynamic, transport and further properties can be calculated.

The following input pairs are implemented:

``` (p,t) (p,h) (p,s) (p,v)

(t,h) (t,s) (t,v)

(p,x) (t,x) (h,x) (s,x)

(h,s)
```

Usage

Install the crate

bash cargo add if97

The type of functions are provided in the if97 package:

```rust fn(f64,f64,i32) -> f64 ``````

• the first,second input parameters: the input propertry pairs
• the third input parameter: the property ID of the calculated property - o_id
• the return: the calculated property value of o_id

```rust pt(p:f64,t:f64,oid:i32)->f64 ph(p:f64,h:f64,oid:i32)->f64 ps(p:f64,s:f64,oid:i32)->f64 pv(p:f64,v:f64,oid:i32)->f64

th(t:f64,h:f64,oid:i32)->f64 ts(t:f64,s:f64,oid:i32)->f64 tv(t:f64,v:f64,o_id:i32)->f64

px(p:f64,x:f64,oid:i32)->f64 tx(p:f64,x:f64,oid:i32)->f64 hx(h:f64,x:f64,oid:i32)->f64 sx(s:f64,x:f64,oid:i32)->f64

hs(h:f64,s:f64,o_id:i32)->f64 ``` Example

```rust use if97::*; fn main() {

let p:f64 = 3.0;
let t:f64= 300.0-273.15;

let h=pt(p,t,OH);
let s=pt(p,t,OS);
let v=pt(p,t,OV);
println!("p={p:.6} t={t:.6} h={t:.6} s={s:.6} v={v:.6}");

} ```

Properties

| Propertry | Unit | Symbol | oid | oid(i32)| | ------------------------------------- | :---------: |:------:|-----:|:--------:| | Pressure | MPa | p | OP | 0 | | Temperature | °C | t | OT | 1 | | Density | kg/m³ | d | OD | 2 | | Specific Volume | m³/kg | v | OV | 3 | | Specific enthalpy | kJ/kg | h | OH | 4 | | Specific entropy | kJ/(kg·K) | s | OS | 5 | | Specific exergy | kJ/kg | e | OE | 6 | | Specific internal energy | kJ/kg | u | OU | 7 | | Specific isobaric heat capacity | kJ/(kg·K) | cp | OCP | 8 | | Specific isochoric heat capacity | kJ/(kg·K) | cv | OCV | 9 | | Speed of sound | m/s | w | OW | 10 | | Isentropic exponent | | ks | OKS | 11 | | Specific Helmholtz free energy | kJ/kg | f | OF | 12 | | Specific Gibbs free energy | kJ/kg | g | OG | 13 | | Compressibility factor | | z | OZ | 14 | | Steam quality | | x | OX | 15 | | Region | | r | OR | 16 | | Isobaric volume expansion coefficient | 1/K | ec | OEC | 17 | | Isothermal compressibility | 1/MPa | kt | OKT | 18 | | Partial derivative (∂V/∂T)p | m³/(kg·K) | dvdtcp | ODVDT | 19 | | Partial derivative (∂V/∂p)T | m³/(kg·MPa) | dvdpct | ODVDP | 20 | | Partial derivative (∂P/∂T)v | MPa/K | dpdtcv | ODPDT | 21 | | Isothermal Joule-Thomson coefficient | kJ/(kg·MPa) | iJTC | OIJTC | 22 | | Joule-Thomson coefficient | K/MPa | joule| OJTC | 23 | | Dynamic viscosity | Pa·s | dv | ODV | 24 | | Kinematic viscosity | m²/s | kv | OKV | 25 | | Thermal conductivity | W/(m.K) | tc | OTC | 26 | | Thermal diffusivity | m²/s | td | OTD | 27 | | Prandtl number | | pr | OPR | 28 | | Surface tension | N/m | st | OST | 29 | | Static Dielectric Constant | | sdc | OSDC | 30 | | Isochoric pressure coefficient | 1/K | pc | OPC | 31 | | Isothermal stress coefficient | kg/m³ | betap| OBETAP| 32 | | Fugacity coefficient | | fi| OFI | 33 | | Fugacity | MPa | fu| OFU | 34 |