# SEUIF97 **Repository Path**: volker/SEUIF97 ## Basic Information - **Project Name**: SEUIF97 - **Description**: The high-speed IAPWS-IF97 implementation in C - **Primary Language**: Unknown - **License**: MIT - **Default Branch**: c_src - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 3 - **Created**: 2025-03-20 - **Last Updated**: 2025-08-25 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README # SEUIF97 [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.8242452.svg)](https://doi.org/10.5281/zenodo.8242452) This is the C implementation of the high-speed IAPWS-IF97 package **seuif97**. It is suitable for computation-intensive calculations，such as the simulation of non-stationary processes, on-line process monitoring and optimizations. Through the high-speed library, the results of the IAPWS-IF97 are accurately produced several times faster than repeated squaring method and `math.pow()` of the C standard library. The speed of SEUIF97 is also far faster than various approximate equations and algorithms for a fast calculation of the properties for water and steam. **The Fast Methods** * the shortest addition chain algorithm computes the integer power of a number quickly * apply Horner's rule to compute a set of powers and avoid to calculate the power of the same exponential repeatedly * the recursive method computes the value of multiple polynomials to avoid the calculation of the same item once again In addition to the source code, the repository provides * the compiled shared libraries using GCC: [/shared_lib/](./shared_lib/) * the interfaces and examples: [/demo/](./demo) * C/C++, Python, C#, Java, Excel VBA, MATLAB, Rust, Fortran, Pascal, Modelica, Golang ## Building the shared library * make ```bash make ``` * cmake ```bash cmake -B ./build/ cmake --build ./build/ --config Release ``` **The compiled shared libraries using GCC** * [Windows(x86/64)](./shared_lib/Windows): `libseuif97.dll` * [Linux(x64)](./shared_lib/Linux): `libseuif97.so` ## Functions of the SEUIF97 Shared Library Functions of water and steam propertiesand the thermodynamic process of steam turbine are provided in the **SEUIF97** **Water and Steam Properties** Using the SEUIF97, you can set the state of steam using various pairs of know properties to get any output properties you wish to know, including in the [30 properties in libseuif97](#properties-in-libseuif97). 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) ``` The type of propertry functions are provided in the package ```c ??(in1,in2,o_id) ``` * the first,second input parameters : the input propertry pairs * the third input parametes: the property ID of the calculated property - [o_id](#properties) * the return: the calculated property value of `o_id` **Thermodynamic Process of Steam Turbine** * Isentropic Enthalpy Drop：ishd(pi,ti,pe) ```txt pi - inlet pressure(MPa); ti -inlet temperature(°C) pe - outlet pressure(MPa) ``` * Isentropic Efficiency(0~100)： ief(pi,ti,pe,te) (superheated steam zone) ```txt pi - inlet pressure(MPa); ti - inlet temperature(°C) pe - outlet pressure(MPa); te - outlet temperature(°C) ``` **The Function Prototype in C** ```c // Functions of Properties double pt(double p, double t, int o_id); double ph(double p, double h, int o_id); double ps(double p, double s, int o_id); double pv(double p, double v, int o_id); double th(double t, double h, int o_id); double ts(double t, double s, int o_id); double tv(double t, double v, int o_id); double hs(double h, double s, int o_id); double px(double p, double x, int o_id); double tx(double t, double x, int o_id); double hx(double h, double x, int o_id); double sx(double s, double x, int o_id); //The Functions for Thermodynamic Process of Steam Turbine double ishd(double pi, double ti, double pe); double ief(double pi, double ti, double pe, double te); ``` ## Install SEUIF97 Use the shared library from one programming language, you may 1. Put the shared library in the default `Lib` path of OS or the programming language * **Windows(x86/64)** * copy `libseuif97.dll` in the [Windows/x86](./shared_lib/Windows/x86) or [Windows/x64](./shared_lib/Windows/x64) folder to a default path of Windows32/64's DLL: `C:\Windows\System` * **Linux(x64)** * copy `libseuif97.so` in the [Linux/x64](./shared_lib/Linux/x64) folder to a default path of Linux shared lib : `/usr/lib`/ 2. Add the API file of the programming language to its `API` path * The API paths of different programming languages are different,please refer to the [Examples](./demo/) of different programming languages ## Interfaces and Examples * [./demo/](./demo) | Language | Interface | |:-----------------------------------:|:-------------------------------------------------| | [C/C++](./demo/demo-c) | [seuif97.h](./demo/demo-c/include/seuif97.h) | | [Python](./demo/demo-python) | [seuif97.py](./demo/demo-python/seuif97.py) | | [C#](./demo/demo-csharp) | [seuif97.cs](./demo/demo-csharp/seuif97.cs) | | [Excel VBA](./demo/ExcelVBA) | [seuif97.bas](./demo/ExcelVBA/seuif97.bas) | | [Java](./demo/demo-java) | [seuif97.java](./demo/demo-java/seuif97.java) | | [MATLAB64](./demo/MATLAB64) | [seuif97.m](./demo/MATLAB64/seuif97/seuif97.m) | | [Rust](./demo/demo-rust) | [seuif97.rs](./demo/demo-rust/src/seuif97.rs) | | [Fortran](./demo/demo-Fortran) | [seuif97.f08](./demo/demo-fortran/seuif97.f08) | | [Pascal](./demo/demo-pascal) | [seuif97.pas](./demo/demo-pascal/seuif97.pas) | | [Modelica](./demo/demo-modelica) | [seuif97.mo](./demo/demo-modelica/demomodelica/seuif97.mo) | | [Golang](./demo-go) | **Example** [demo.go](./demo/demo-go/demo.go) | You can modify these interfaces provided in the repository to your own APIs. **The Selected Examples** **Python** * [T-S Diagram](./demo/demo-python/Diagram_T-S.py) * [H-S Diagram](./demo/demo-python/Diagram_H-S.py) * [H-S Diagram of Steam Turbine Expansion](./demo/demo-python/Turbine_H-S.py) **C++** * [H-S Diagram of Steam Turbine Expansion](./demo/demo-c/Turbine_H-S.cpp) ## Properties | Propertry | Unit | Symbol | o_id | | ------------------------------------- | :---------: |:-----: |:---------: | | Pressure | MPa | p | 0 | | Temperature | °C | t | 1 | | Density | kg/m^3 | ρ | 2 | | Specific Volume | m^3/kg | v | 3 | | Specific enthalpy | kJ/kg | h | 4 | | Specific entropy | kJ/(kg·K) | s | 5 | | Specific exergy | kJ/kg | e | 6 | | Specific internal energy | kJ/kg | u | 7 | | Specific isobaric heat capacity | kJ/(kg·K) | cp | 8 | | Specific isochoric heat capacity | kJ/(kg·K) | cv | 9 | | Speed of sound | m/s | w | 10 | | Isentropic exponent | | k | 11 | | Specific Helmholtz free energy | kJ/kg | f | 12 | | Specific Gibbs free energy | kJ/kg | g | 13 | | Compressibility factor | | z | 14 | | Steam quality | | x | 15 | | Region | | r | 16 | | Isobaric cubic expansion coefficient | 1/K | ɑv | 17 | | Isothermal compressibility | 1/MPa | kT | 18 | | Partial derivative (∂V/∂T)p | m3/(kg·K) |(∂V/∂T)p| 19 | | Partial derivative (∂V/∂P)T | m3/(kg·MPa) |(∂V/∂P)T| 20 | | Partial derivative (∂p/∂t)v | MPa/K |(∂p/∂t)v| 21 | | Isothermal throttling coefficient | kJ/(kg·MPa) | δt | 22 | | Joule-Thomson coefficient | K/MPa | μ | 23 | | Dynamic viscosity | kg/(m·s) | η | 24 | | Kinematic viscosity | m^2/s | ν | 25 | | Thermal conductivity | W/(m.K) | λ | 26 | | Thermal diffusivity | um^2/s | a | 27 | | Prandtl number | | Pr | 28 | | Surface tension | N/m | σ | 29 | ## Publications * 王培红,贾俊颖,程懋华. 水和水蒸汽热力性质IAPWS-IF97公式的通用计算模型[J]. 动力工程,2001,21(6)：1564-1567 [[ pdf ]](./doc/水和水蒸汽热力性质IAPWS-IF97公式的通用计算模型.pdf) * 芮嘉敏,孙振业,程懋华. 基于最短加法链状态空间树的IAPWS-IF97快速计算方法[J]. 汽轮机技术,2017,59(4):245-247 [[ pdf ]](./doc/基于最短加法链状态空间树的IAPWS-IF97快速计算方法.pdf) ## Cite as * Cheng Maohua. (2023). The C implementation of the high-speed IAPWS-IF97 package: SEUIF97 (1.2.0). Zenodo. https://doi.org/10.5281/zenodo.8242452