Gavin Wiggins

Gavin Wiggins

I'm a research scientist at the Oak Ridge National Laboratory in Tennessee. My current work is developing computational models to simulate the fast pyrolysis of biomass in fluidized reactors. This research is part of the Consortium for Computational Physics and Chemistry for the U.S. DOE Bioenergy Technologies Office. I am also involved in various battery simulation activities as part of the Consortium for Advanced Battery Simulation project. As an enthusiastic developer, I organize the Knoxville CocoaHeads and KnoxPy programming groups. I'm also organizer of the Back to the Mac conference.

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Un1ts. A comprehensive unit converter for the Mac. The original version of the app was written in Objective-C and was temporarily removed from the App Store. I have rereleased Un1ts as a completely new version written in Swift and SwiftUI to support the latest features of macOS. [URL]

WeathrClip. WeathrClip provided current weather conditions, 5-day forecast, hourly forecast, and precipitation radar for the Mac and iPhone. I discontinued this app because the Weather Underground API is no longer available.


Swift Programming for macOS. There are plenty of books, videos, and online resources for developing iOS apps. Despite the fact that iPhone and iPad apps require a Mac for code development, there is little information about actually creating native Mac applications. This book demonstrates various aspects of modern Mac app development using the latest versions of Swift and SwiftUI. Hopefully the examples will provide a useful resource for Mac developers. [Read]

Pythonic Programming. There are numerous resources for learning Python but sometimes you just want to see a straightforward example of the language. This book is a collection of code examples using the Python programming language. [Read]


Using Lists in Python. KnoxPy online meetup in Knoxville, TN on October 1, 2020. [URL]

Getting Started with Python. KnoxPy online meetup in Knoxville, TN on September 10, 2020. [PDF] [URL]

String formatting in Python. KnoxPy meeting in Knoxville, TN on May 14, 2020. Live demo via Jupyter Notebook.

Reduced-Order Modeling Techniques for Fluidized-Bed Biomass Pyrolysis. TC Biomass conference in Rosemont, IL on October 7, 2019. [PDF]

Python Workshop. KnoxPy meeting in Knoxville, TN on September 5, 2019. [PDF]

A Pythonic Equivalent Circuit Model for Battery Research. SciPy 2019 conference in Austin, TX on July 10, 2019. [PDF]

Using Python to Model Biomass Pyrolysis Reactors. SciPy 2019 conference in Austin, TX on July 10, 2019. [PDF]

Unit Conversion in Swift. Knoxville CocoaHeads meeting in Knoxville, TN on April 29, 2019. [PDF]

Combining high and low-order computational models to simulate biomass fast pyrolysis reactors. AIChE Spring Meeting and 8th World Congress on Particle Technology in Orlando, FL on April 23, 2018. [PDF]

Scraping with Selenium. KnoxPy meeting in Knoxville, TN on April 5, 2018. [PDF]

Realm Mobile Database. Knoxville CocoaHeads meeting in Knoxville, TN on April 18, 2017. [PDF]

Modeling the impact of biomass particle size distribution and shape on heating behavior during fast pyrolysis. TCS 2016 Symposium in Chapel Hill, NC on November 1, 2016. [PDF]

Modeling the impact of biomass particle residence time on fast pyrolysis yield and composition. AIChE Annual Meeting in San Francisco, CA on November 13, 2016. [PDF]

Firebase for iOS. Knoxville CocoaHeads meeting in Knoxville, TN on August 16, 2016. [PDF]

NSUserDefaults in Swift. Knoxville CocoaHeads meeting in Knoxville, TN on April 19, 2016. [PDF]

Overview of NumPy in Python. KnoxPy meeting in Knoxville, TN on April 7, 2016. [PDF]

An Introduction to Git and GitHub. Knoxville CocoaHeads meeting in Knoxville, TN on October 20, 2015. [PDF]

Resolution Independence with PaintCode. Knoxville CocoaHeads meeting in Knoxville, TN on June 9, 2015. [PDF]

Modeling Thermochemical Biomass Pyrolysis in Python. PyKnoxville meeting in Knoxville, TN on April 8, 2015. [PDF]

Low-order modeling of biomass particle mixing and reaction in a bubbling-bed fast pyrolysis reactor. AIChE 2014 Annual Meeting in Atlanta, GA on November 20, 2014. [PDF]

Particle-scale computational modeling of woody biomass pyrolysis. TCS 2014 Symposium in Denver, CO on September 4, 2014. [PDF]


If you do not have access to a publication, please contact me and I will be genuinely delighted to send you a copy of the manuscript. Publications are also listed on my ORCID profile.

Validation and application of a multiphase CFD model for hydrodynamics, temperature field and RTD simulation in a pilot-scale biomass pyrolysis vapor phase upgrading reactor. Chemical Engineering Journal, volume 388, article 124279, 2020. [URL]

Integrated Particle- and Reactor-Scale Simulation of Pine Pyrolysis in a Fluidized Bed. Energy and Fuels, volume 32, issue 10, pages 10683-10694, 2018. [URL]

Chemics-Reactors: A Preliminary Python Program for Implementing Network Models of Multiphase Reactors. Technical Report, number ORNL/TM-2017/748, 2018. [URL]

Simulating Biomass Fast Pyrolysis at the Single Particle Scale. From the book 'Fast Pyrolysis of Biomass', chapter 11, pages 231-253, 2017. [URL]

Low-Order Modeling of Internal Heat Transfer in Biomass Particle Pyrolysis. Energy and Fuels, volume 30, issue 6, pages 4960-4969, 2016. [URL]

Development of a Low-Order Computational Model for Biomass Fast Pyrolysis: Accounting for Particle Residence Time. Technical Report, number ORNL/TM-2016/69, 2016. [PDF]

Coupling DAEM and CFD for simulating biomass fast pyrolysis in fluidized beds. Journal of Analytical and Applied Pyrolysis, volume 117, pages 176-181, 2016. [URL]

Biomass Particle Models with Realistic Morphology and Resolved Microstructure for Simulations of Intraparticle Transport Phenomena. Energy and Fuels, volume 29, issue 1, pages 242-254, 2015. [URL]

Evaluation of Biomass and Coal Briquettes for a Spreader Stoker Boiler Using an Experimental Furnace — Modeling and Test. Thesis, Clemson University, 2011. [URL]

System Modeling of ORNL's 20 MW(t) Wood-fired Gasifying Boiler. Conference: American Flame Research Committee, Pacific Rim Combustion Symposium, 2010. [URL]

Developed by Gavin Wiggins. Last updated on November 25, 2020.
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