final presentation evan greer

8/13/2019 Final Presentation Evan Greer

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Evan Greer,Mentor: Dr. Marcelo Kobayashi,HARP REU ProgramAugust 2, 2012Contact: [email protected]

globalwindgroup.com


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Introduction and Motivations Creating the geometry

Stationary study of turbine geometry Rotating study of turbine geometry Future Plans Acknowledgements


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Energy Security

High reliability of fossil fuels leads to widespread use

Set amount of fossil fuel outputs a setamount of energy


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Introduction of reliability to renewableresources, wind energy in particular

Wind energy is subject to low reliability dueto changing weather conditions

Scale predictions of large scale weatherpatterns to make predictions about theenvironment around the turbine


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The effects of local topography on efficiencywill be studied

WRF (weather research and forecasting)model coupled with CFD models

This is the future goal of this research but firsta working model of the turbine must becreated and studied


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Used a sample geometry fromComsol Multiphysics

Played with initial conditions

and mesh sizes Learned how to use the Comsol

Multiphysics software

Studied introductory tutorialbuilding a busbar geometry

Learned how to set up fluid flowand thermoelectric physics


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Approximated the geometry of atypical wind turbine

Height of the tower set at 300 ft

Length of the rotors set at 200 ft

Length of the nacelle set at 40 ft


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Front View Side View


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Created for theimplementation of the slidingmesh

Cylindrical region with aheight of 80 ft encompassingthe blades

Domain to move with the

blades


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Region where boundaryand initial conditions are tobe defined

Created a cylindricalregion behind the slidingregion to study wake

Material for the flow setas air and material forturbine set as aluminum


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Generated mesh usingtetrahedral elements

Mesh had to be refinedaround blades

Mesh consisted of 93349elements


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Ran a stationary turbulent flow study using ak-model

This model has the purpose of understandinghow fluid flow is affected by geometry


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Used a simple turbulent flow physical model

Stationary study step with no timedependence

Inlet velocity of 3.219 m/s, this is the averageannual wind speed of Honolulu reported byNOAA [1]


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Outlet condition was also set to atmosphericpressure

Also, a volume force was introduced on theflow domain


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Used Rotating Machinery,Turbulent Flow physical model

Moving domains are coupledwith stationary domains by

identity pairs

At these identity pairs, a fluxcontinuity boundary conditionis applied

Navier-Stokes equations areformulated based on rotatingand stationary coordinatesystems


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Convergence of time stepped solution

Solution would get stuck on calculation oftime step

Many issues with script files and runs onsupercomputer


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Issues with licensing Jobs would terminate because of lack of licensing on

multiple nodes

Solved with batch and cluster computing add-on tojob configurations within Comsol

Issues with node communication Comsol would get kicked nodes

Solved using MPD (Multi processing Daemon) used byComsol to communicate between nodes

Accomplished through modification of script files withthe help of Andrew Yukitomo


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Isolated rotatinggeometry

Try to get rotatingblade workingwithout pairing

Added input andoutput condition


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Added pairing and flowcontinuity conditionbetween stationary and

rotating domains

Used overlapping domainsand input and outputconditions


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Used non-overlappingdomains

Got rid of input and outputconditions, instead used apressure point constraint

Increased number of

iterations used by the solver


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Complete the set up of the full rotatinggeometry

Get the blade study to run for larger time scales Further work needs to be done to understand where

and why the convergence errors are occurring

Understanding how to make a more accurate mesh

Introduce the stationary wake region and a twodimensional pairing region


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Introduce the flow domain and threedimensional pairing and get the complete

model to run

Get the rotation of the turbine to be dictatedby inlet velocity conditions

This will involve delving deeper into the interfaceto understand how to program physical models


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Project benchmarks:

Creating geometry

Modeling stationary case Implementation of sliding mesh

Implementation of Large Eddy Simulation

Implementation of WRF data This research will be continued under a NASA

space grant in the fall


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I would like to thank Dr. Susan Brown for giving methe opportunity to be a part of this program and Dr.Marcelo Kobayashi for his continued support andallowing me to share in his research. I also want to

acknowledge Andrew Yukitomo for his continued helpwith script files and supercomputing issues and HOSCfor allowing us to use the supercomputing facilities forour work.

"This material is based upon work supported by the National ScienceFoundation under Grant No. 0852082. Any opinions, findings, andconclusions or recommendations expressed in this material are those of theauthor(s) and do not necessarily reflect the views of the National ScienceFoundation."


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[1] Delliger, Dan, 2008, Average Wind Speed, Comparative Climate Data,http://lwf.ncdc.noaa.gov/oa/climate/online/ccd/avgwind.html(July 5, 2012)

[2] Laminar Flow in a Baffled Stirred Mixer. Comsol Multiphysics 4.3 sampleprogram documentation, 2012
http://lwf.ncdc.noaa.gov/oa/climate/online/ccd/avgwind.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/online/ccd/avgwind.html

final presentation evan greer

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