SEUIF97 This is the Rust implementation of the high-speed IAPWS-IF97 package seuif97 with C and Python binding. 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 5-20x speed-up compared to using the powi() of the Rust standard library in the forloop directly when computing the basic equations of Region 1,2,3. The Fast Methods The multi-step method unleashes the full power of the compiler optimizations while using powi() with the for loop The recursive method computes the polynomial values of the base variable and its derivatives In the package, 36 thermodynamic, transport and further properties can be calculated. The following 12 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 cargo add seuif97 The type of functions are provided in the package: struct o_id_region_args { o_id: i32, region: i32, } fn<R>(f64,f64,R) -> f64 where R: Into<o_id_region_args>, the first,second input parameters(f64) : the input propertry pairs the third and fourth input parametes<R>: the third : the property ID of the calculated property - o_id the fourth option parameter: the region of IAPWS-IF97 the return(f64): the calculated property value of o_id pt<R>(p:f64,t:f64,o_id_region:R)->f64 ph<R>(p:f64,h:f64,o_id_region:R)->f64 ps<R>(p:f64,s:f64,o_id_region:R)->f64 pv<R>(p:f64,v:f64,o_id_region:R)->f64 th<R>(t:f64,h:f64,o_id_region:R)->f64 ts<R>(t:f64,s:f64,o_id_region:R)->f64 tv<R>(t:f64,v:f64,o_id_region:R)->f64 hs<R>(h:f64,s:f64,o_id_region:R)->f64 px(p:f64,x:f64,o_id:i32)->f64 tx(p:f64,x:f64,o_id:i32)->f64 hx(h:f64,x:f64,o_id:i32)->f64 sx(s:f64,x:f64,o_id:i32)->f64 Example use seuif97::*; 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); // set the region let v=pt(p,t,(OV,1)); println!("p={p:.6} t={t:.6} h={t:.6} s={s:.6} v={v:.6}"); } The C binding Building the dynamic link library cdecl cargo build -r --features cdecl stdcall: Win32 API functions cargo build -r --features stdcall The convenient compiled dynamic link libraries are provided in the ./dynamic_lib/ seuif97.dll: Windows64 and Windows32 libseuif97.so: Linux64 The functions in C double pt(double p,double t,short o_id); double ph(double p,double h,short o_id); double ps(double p,double s,short o_id); double pv(double p,double v,short o_id); double tv(double t,double v,short o_id); double th(double t,double h,short o_id); double ts(double t,double s,short o_id); double hs(double h,double s,short o_id); double px(double p,double x,short o_id); double tx(double t,double x,short o_id); double hx(double h,double x,short o_id); double sx(double s,double x,short o_id); Examples ./demo_using_lib/: C, Python, C#, Excel VBA, Java, Fortran #include <stdlib.h> #include <stdio.h> #include <string.h> #define OH 4 #define OS 5 extern double pt(double p,double t,short o_id); int main(void) { double p = 16.0; double t = 530.0; double h = pt(p, t, OH); double s = pt(p, t, OS); printf("p,t %f,%f h= %f s= %f\n", p, t, h, s); return EXIT_SUCCESS; } The Python binding Install pip install seuif97 Examples from seuif97 import * OH=4 p=16.0 t=535.1 # ??(in1,in2,o_id) h=pt(p,t,OH) # ??2?(in1,in2) s=pt2s(p,t) print(f"p={p}, t={t} h={h:.3f} s={s:.3f}") T-S Diagram ./demo_using_lib/Diagram_T-S.py Properties Propertry Unit Symbol o_id o_id(i32) Pressure MPa p OP 0 Temperature °C t OT 1 Density kg/m³ ρ 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 k 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 Isobari cubic expansion coefficient 1/K ɑv OEC 17 Isothermal compressibility 1/MPa kT OKT 18 Partial derivative (∂V/∂T)p m³/(kg·K) (∂V/∂T)p ODVDT 19 Partial derivative (∂V/∂p)T m³/(kg·MPa) (∂v/∂p)t ODVDP 20 Partial derivative (∂P/∂T)v MPa/K (∂p/∂t)v ODPDT 21 Isothermal throttling coefficient kJ/(kg·MPa) δt OIJTC 22 Joule-Thomson coefficient K/MPa μ OJTC 23 Dynamic viscosity Pa·s η ODV 24 Kinematic viscosity m²/s ν OKV 25 Thermal conductivity W/(m.K) λ OTC 26 Thermal diffusivity m²/s a OTD 27 Prandtl number Pr OPR 28 Surface tension N/m σ OST 29 Static Dielectric Constant ε OSDC 30 Isochoric pressure coefficient 1/K β OPC 31 Isothermal stress coefficient kg/m³ βp OBETAP 32 Fugacity coefficient fi OFI 33 Fugacity MPa f* OFU 34 Relative pressure coefficient 1/K αp OAFLAP 35