Worked examples

2017-05-21T15:17:35Z

Kchittur:

{{missingimages}}

This is a list of worked example models that were written in the spirit of experimentation while working on the functionality of ASCEND.

See also [[:Category:Tutorials]] and [[:Category:Examples]].

== Steam power station ==

ASCEND can model complete [[Rankine cycle|Rankine power cycles]] including regeneration and reheat. The same models work for a variety of fluids via [[FPROPS]]. See {{src|models/johnpye/fprops/rankine_fprops.a4c}}.

Note that the diagram below was created with Dia; we are working on a [[canvas-based modeller for ASCEND]] but it's still in early stages of development.

[[Image:RankineRegenReheat.png|400px]] [[Image:Rankine-Ts.png|400px]]

== Four bar linkage ==

{{src|models/johnpye/fourbar.a4c}}

This example shows a (static) system with simple geometric constraints. It is solved for a range of angles for one member, and the position of the other members is determined. Then a nice plot is built up by repeated running the ASCEND model and accumulating the results using [[ExtPy]].

[[Image:Fourbar.png|thumb|402px|none]]

== Thermal equilibrium ==

{{src|models/johnpye/thermalequilibrium2.a4c}}

This is a simple model of thermal equilibrium between two masses of steam with a simple constant heat transfer coefficient between them. The model uses external [[freesteam]] IAPWS-IF97 steam tables and the [[IDA]] integrator.

[[Image:Thermalequilibrium.png|thumb|400px|none|Graph of the temperatures of the two masses over time. The transition through the saturation region is visible.]]

== Simple advection equation ==

{{src|models/johnpye/advection.a4c}}

This model is a study of the simple advection equation, following [http://dx.doi.org/10.1177/003754977803100205 a discussion] published by Carver and Hinds in ''Simulation'' (1978). Just as with the explicit integration method discussed in that paper, we also see instability when using the [[IDA]] implicit BDF integrator here. The output in each case was generated by copying the contents of the Integrator tab and pasting into OpenOffice and plotting there.

[[Image:2p-upwind.png|200px]][[Image:3p-upwind.png|200px]]
[[Image:4p-biased.png|200px]][[Image:Central-diff.png|200px]]

== More examples ==

For some more detailed examples, see the page [[Category:Examples]], which includes:

* [[Vapor-liquid equilibrium]]
* [[Calculation of sun position]]
* [[Damped response]]
* [[Conditional modelling]] (examples of models with IF/ELSE-style behaviour in their equations)
* [[Optimisation of frame geometry]]
* [http://chetoolbox.uah.edu/courseware/toolbox/ascend/ Chemical thermodynamics, mass/energy balance] and more, from [[User:Kchittur|Krishnan Chittur]].
* [[Combined-cycle gas turbine]]

[[Category:Documentation]]
[[Category:Examples]]

ASCEND - User contributions [en]

Worked examples