Fluid as overarching term gaseous and liquid material entities

[l-emele]

Description of the issue

We defined turbine as: A turbine is an energy converting device that converts energy from a moving fluid flow into rotational energy. Also in the current definition attempt of pump in #78 we used the term fluid: A pump is an energy converting device that converts rotational energy into kinetic energy and potential energy of a fluid.

So we should define fluid. A fluid is an overarching term for gas and liquid material entities. Simplified, one can describe gaseous material entities as compressible fluids and liquid material entities as incompressible fluids.

Ideas of solution

If you already have ideas for the solution describe them here

Workflow checklist

• [ ] I discussed the issue with someone else than me before working on a solution
• [ ] I already read the latest version of the workflow for this repository
• [ ] The goal of this ontology is clear to me

I am aware that

• [ ] every entry in the ontology should have a definition
• [ ] classes should arise from concepts rather than from words

[sfluegel05]

ENVO has this concept as well: fluid environmental material is defined as A liquid or a gas.

For the OEO, I would suggest to add it as an equivalent class which is equivalentTo material entity and has state of matter (gaseous or liquid or plasmatic).

[l-emele]

Wow, that's a very simple definition :)

I'll assign you this issue.

[sfluegel05]

As a definition of fluid I suggest A fluid is a material entity which is a liquid or a gas.

[l-emele]

Sounds good, I think this can be implemented.

Also the axiom turbine uses some fluid can be added.