Author Archives: chemecomp

About chemecomp

Bruce A. Finlayson, retired Rehnberg Professor of Chemical Engineering, University of Washington

System Mass Balances in Excel

I’ve added some more material to the web site – solving mass balances for processes with recycle streams, using Comsol. In process simulators, one usually solves the equations by taking the input to a unit, solving that unit, taking the … Continue reading

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How to solve CSTRs in Comsol

I’ve added some material to the web site – solving equations for Continuous Stirred Tank Reactors (CSTR) using Comsol. There are some things you have to be careful of when the parameters lead to multiple solutions or to no steady … Continue reading

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For Beginners with Comsol and with Excel

If you are a new user of Comsol Multiphysics, there is a nifty way to work through the first example in the book. A pdf version of the first example in Chapter 9 (heat conduction) is available at http://www.ChemEComp.com. You … Continue reading

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New Resources Added to Website

I’ve added new resources to the website, chemecomp.com. There you will find Problem 9.26 worked. This is a problem to examine the proposition that if one has a transport problem with a large velocity (Peclet number) it is easier if … Continue reading

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In the December 2nd blog, I talk about solving the algebraic equations in early chapters of the book using Comsol Multiphysics rather than just Excel, MATLAB, and AspenPlus. I’ve added some examples – another case of two simultaneous equations from … Continue reading

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More on Solving Algebraic Equations in Comsol Multiphysics

In the December 2nd blog, I talk about solving the algebraic equations in early chapters of the book using Comsol Multiphysics rather than just Excel, MATLAB, and AspenPlus. I’ve added some examples – another case of two simultaneous equations from … Continue reading

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Solving algebraic equations with Comsol

On the website, I have added a link to a pdf document that shows how to set up a simple problem of transient heat transfer in a sphere. A reader asked me details about doing this in 1D (where you … Continue reading

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Hints for using MATLAB

What do I do first? BE A DETECTIVE! 1. Try the command: help commandname (replacing commandname with the subroutine or subprogram you are trying to use). 2. Next, remove the ; from your statements and verify that each step in … Continue reading

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Guidelines for CFD work and reports

Here are some suggestions for what a report using computational fluid dynamics (CFD) should include: A.    Describe the problem in prose. B.    This is a checklist of items to be written down: Equations solved, and values of any parameters in … Continue reading

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More information about the second edition

The book now has a website with lots of information (chemecomp.com)– some things that go beyond the book and give additional theory: shortcut distillation, links for energy problems in Aspen, theory and simplifications for laminar diffusion fluid interfaces, parameter estimation … Continue reading

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