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fluid.sh

fluid.sh is a shell script which utilized wget to acquire fluid properties from the NIST Chemistry WebBook in a format suitable for further processing with shell scripts or e.g. xmgrace. It supports the full functionality provided by the website!

The script takes the same input as command line arguments you need to enter on the web forms. It produces a ASCII text file containing the respective data points in columns headed by a well readable description. The advantage is that you do not need to "click" through three web pages and export the result - you can do it with one command in the shell! This makes it possible to introduce it in shell scripts to automatize the analysis of other data, to compare or just to save time.

IMPORTANT NOTE!

Every usage of fluids.sh produces traffic on the NIST web server. So please be careful, especially if you add a call to fluids.sh in a script.

Till yet this service is provided from NIST for free. So please be fair! If you need to access this data on a daily basis or within a commercial background, you should consider to buy NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP)!

Requirements

The script is written to be interpreted with the Bourne shell (sh), which is usually available on all Unix/Linux platforms. Despite the standard command line tools (cat, tail,...) the only dependency is wget to request and retrieve the data from the NIST web server.

Installation

Just copy the fluids.sh file in a folder which is included in your $PATH or add the folder to the $PATH variable.

Usage

General:

Just type fluids.sh -h to get the help message. You need to specify the substance of interest by an ID. To get a list of substances and the respective ID, type fluids.sh -show. For further information about the handling of the units of the input and output quantities type fluids.sh -units.

Example:

Retrieve an isotherm (-it) of water (-id C7732185) for T/K=725.5 from p/MPa=1.0 to 10.0 with p.increment/MPa=0.5 and use SI units:

fluids.sh -id C7732185 -it -T 725.5 -pl 1.0 -ph 10.0 -i 0.5 -si

Citation

Please cite properly! In general you should cite

P.J. Linstrom and W.G. Mallard, Eds., NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg MD, 20899, http://webbook.nist.gov, (retrieved <date>)

for the source.

If you make use of particular data in a publication (paper, thesis,..) you should have a look at the respective NIST Chemistry WebBook/Fluid properties website to refer to the individual publication regarding the property of interest.