Frequently Asked Questions

General

What is the relation between DWSIM, COCO and ChemSep?

The COCO Simulator is used as a reference for validation of thermodynamic and unit operation models. DWSIM uses ChemSep's binary interaction parameter IPD files for UNIQUAC, NRTL, PR and SRK models, and group contribution data GCD files for UNIFAC, Mod. UNIFAC and Joback models. You can use the ChemSep LITE component database in DWSIM but it isn't included in the installation package - you must install ChemSep first and convert the database to a compatible format [instructions here].

Is there any kind of feature validation?

As the features are implemented, they are tested for (un)expected behavior. Currently we are building a validation program for all features, comparing the results obtained in DWSIM with the ones from the other simulators (free and commercial). A validation report for some features will be released soon.

Features & Limitations

How many phases are supported by DWSIM thermodynamic models?

Currently DWSIM only supports Vapor-Liquid Equilibria (VLE) systems. There is some kind of solids support through the Hydrate Calculation Utility but it is not directly related to the simulation itself. LLE/VLLE is not supported directly, although there is a property package which uses the PR EOS and considers total liquid immiscibility between water and hydrocarbons.

A Multiphase Flash algorithm is being implemented using Michelsen's method, but it is not finished yet.

How and when is the process flowsheet calculated?

The flowsheet is recalculated every time you define/change the basic properties of material streams (temperature, pressure, flow rate and composition) and unit operations. You can force recalculation of the entire flowsheet by using the appropriate buttons on the Calculator toolbar.

What flash types are supported by DWSIM?

Currently DWSIM supports the following Flash types: Pressure-Temperature (PT), Pressure-Enthalpy (PH), Pressure-Entropy (PS), Pressure-Vapor Fraction (PV) and Bubble/Dew Temperature/Pressure calculations.

Does DWSIM support dynamic simulations?

No.

Is DWSIM CAPE-OPEN compliant?

No, but CAPE-OPEN compliancy is definitively on the to-do list.

Project Details

When the DWSIM project started?

The DWSIM Project was started by Daniel Medeiros in the end of 2006 with a very basic set of features, some unit operations and a property package for use with water only. Initially it wasn't meant to be open source, but from version 1.3 and on it is being released as such.

How many people are involved in the project?

Currently there are only one active people working on DWSIM: Daniel Medeiros is the project manager and main developer/tester.

About the people...

Daniel is a Chemical Engineer specialized in Process Engineering, with a four-year experience on the Petroleum Industry working as a Process Engineer. He has experience with design, modeling, simulation, evaluation and operation of petroleum processing / transportation facilities. He is working for PETROBRAS as a Process Engineer since 2007.