COMSOL Tips & Tricks v5.3: Model Methods Feature

New to version 5.3: Model Method Feature
 

To help save time and make analysis more streamlined it is common for us to set up physics with parameterized inputs. Unfortunately, this approach can also mean repeating commands multiple times that can be time consuming and may introduce mistakes. Now you can reduce the time that this process takes and ensure uniformity of implementation by using the Model Methods available in COMSOL Multiphysics® version 5.3. Model Methods allow recording and executing strings of commands, similar to a macro which you can then edit or create custom commands to add functionality to your Modeling.
 
Creating Model Methods in COMSOL is easy. When you click the “Record Code” button, the software records your commands and turns them into JavaScript. Quick Tip: be sure to change the Method type from “Application Method” to “Model Method” if you plan to run the code in the Model Builder window.  You can view, edit, and record additional code in the Application Builder window. You do not need to know Java to build or use Model Methods, but a little bit of programming basics can go a long way if you are interested in further developing robust and/or complex Methods.
 
Example:
 
Here’s a simple method we developed to create a heat transfer node with initialized temperature and convection coefficients, all in a few clicks. Check it out!
 
Step 1) Start a new method
 
Under the Task Ribbon, click "Developer>Record Method". Change the Method type from "Application method" to "Model method". A red box appears around the edge of the model window to indicate code is recording.
 

 

Step 2) Create Default Parameters
 
Add a heat transfer physics node and create the following default parameters the same way you normally would. You can view code created at any time by going to the Application Builder Window.
 


 
Step 3) Assign Parameter Values to Physics
 
Under Heat Transfer, create a heat flux node and change the type to “Convective heat flux.” Enter the parameters into the fields as shown. The following code is automatically generated. Click "Stop Recording".
 


Step 4) Run Model Method
 
Copy your code into any new or existing model file and click “Run Model Method.” The physics setup is automatically generated.
 

 

Time Saving Summary
  Manual Method Model Method
Number of Entries 10 0
Number of Clicks 18 1
Total Time 90 seconds 1.5 seconds

 

And there you have it. Repetitive processes that once took up valuable time and introduced possible errors can now be accomplished quickly and easily. We hope this tip is helpful, and as always, we are here to address your modeling needs through our consulting services and/or training.
 
Happy COMSOLing!

COMSOL Midwest Meeting

COMSOL Midwest Meeting

July 22, 2015

Columbus, OH

 

AltaSim Technologies is joining with COMSOL to bring you the COMSOL Midwest Meeting, an all-day event where you can learn more about modeling with COMSOL Multiphysics® and advance your skills in multiphysics simulation. Together, we will be introducing the Application Builder, and teaching a variety of sessions which will allow you to see how your peers are working with simulations.

 

AltaSim Technologies will be on site all day, teaching several sessions and interacting with participants. Below is a list of the sessions we will be delivering:

 

9:45 – 11:15 AM      Meshing by Joshua Thomas
In this minicourse you will learn techniques for efficient meshing (an important skill for computationally demanding models). Specific topics will include CAD clean-up and how to combine swept meshing with unstructured free meshing in the same geometry. You will also learn how to define virtual mesh features for precise local mesh refinement.

 
9:45 – 11:15 AM      Electromagnetics Modeling by Sergei Yushanov
Learn about the scope of COMSOL Multiphysics® for modeling of electromagnetic problems. The functionality of the core package, the AC/DC, RF, Wave Optics, and Ray Optics Modules will be covered for simulation of problems involving electromagnetic fields in static, transient, low frequency and high frequency regimes.

 

2:45 – 4:15 PM      Best Practices in Multiphysics Analysis by Joshua Thomas
COMSOL Multiphysics® provides unique capabilities to solve Multiphysics problems via numerical methods. This minicourse will examine the best practices for coupling and solving Multiphysics problems using COMSOL Multiphysics. The Multiphysics modeling node will be reviewed along with methods of coupling physics that are not available within this modeling node. Sequential and intimate coupling strategies will be discussed, and the use of fully coupled and segregated solvers will be reviewed.

 

2:45 – 4:15 PM      CFD and Heat Modeling by Luke Gritter
Learn about using COMSOL Multiphysics® for modeling of conjugate heat transfer problems. This minicourse will include a discussion on heat transfer in fluids and solids. For convective heat transfer in fluids, the laminar and turbulent capabilities available within the Heat Transfer Module will be reviewed. These models include k-ε, k-Ω, Algebraic yPlus, L-VEL and low-Reynolds k-ε. Topics for radiative heat transfer include surface-to-surface radiation and radiation in participating media.

 

2:45 – 4:15 PM      Acoustics & Vibrations Modeling by Sergei Yushanov
Acoustic pressure waves in fluids such as air or water interact with surrounding structures resulting in vibrations in solids and absorption in porous materials. The Acoustics Module can simulation these waves and their effects. Recent news and additions to the module are also presented. Application areas include, but are not limited to: muffler design, mobile devices, transducer design, loudspeakers, pipe acoustics, sound insulation materials, acoustic scattering, transmission, and radiation phenomena.

 
4:30 – 6:00 PM     Multi-Phase Flow by Luke Gritter
This minicourse examines the two-phase flow capabilities available in the CFD Module for COMSOL Multiphysics®. Topics will include bubbly flow, Euler-Euler Modeling, Level-Set and Phase Field methodologies for representing two-phase flow. The solution methods for representing stationary and time-dependent solutions will be introduced. In addition, modeling of rotating machinery with mixture models will be discussed.

 

 

This information-packed event is being held at the Bridgewater Banquet & Conference Center,
10561 Sawmill Parkway, Powell, OH 43065. Bring a laptop to the event in order to gain the most hands-on experience, as this will allow you to start a FREE, two-week trial of COMSOL Multiphysics® software.

 

Click here to register. You can also send an email to dave@altasimtechnlogies.com to schedule some one on one time with us during the event.

 

 

MRI – Magnetic Resonance Imaging and Simulation

MRI – Magnetic Resonance Imaging and Simulation

Magnetic Resonance Imaging (MRI) is one of the most widely used and safest imaging modalities for medical diagnostics. Despite this, one of the major technological challenges facing the biomedical imaging world has been the issues created when a patient with metallic medical implants suffers the need (for any reason) for an MRI. With more and more medical implants being used to treat patients, MRI Safety is a growing concern. Consider just a few numbers:

 

Stents:

  • ~600,000 heart stents (1)
  • ~900,000 coronary stents & ~700,000 peripheral artery stents (2, 3)
  • 2M stents per annum (4)

 

MRI:

  • 50.6 MRI exams are performed per 1,000 population – 34 country average and 104.8 MRI exams per 1,000 population – United States (5)

Personally, we know people (and you may too) who are impacted by this current technological limitation. While most implanted devices are accepted as safe for exposure to MRI fields, conditions may arise when there is ambiguity or no specific guidance can be provided, and there is confusion regarding which patients with cardiovascular devices can safely undergo MR examination. Current guidelines based on the results of idealized tests place limits on MR exposure for a large percentage of stents, and the current approach fails to address conditions where finite length stents are joined to form a longer device, and in some cases unsafe examination of patients with implanted devices has occurred (6-10).

 

MR imaging exposes patients with metallic implants to possible risks associated with interaction with the magnetic field to produce translation or rotation, heating due to interaction with the Radio Frequency (RF) energy, or the development of artifacts on the MR image. Electrically conductive implants such as stents, wires, shunts or leads can act to concentrate the electric field in the vicinity of the device leading to excessive local heating that may cause tissue necrosis. The extent to which the electric field is concentrated is dependent on many parameters related to device design, MR machine characteristics and device location within the body. Hence simply listing a device as either safe or unsafe for MR exposure can fail to accurately represent the conditions under which a patient may be safely examined.

 

Currently a device’s compatibility with MR exposure is defined through a series of standardized tests that provide only limited representations of patient conditions; these tests are both time consuming and expensive and often fail to consider alternative device arrangements. Integration into patient guidelines is implemented using the “specific absorption ratio” (SAR) rather than temperature, the underlying cause of tissue necrosis. In addition, this approach does not take into account other factors such as the transient nature of the heating and cooling effects due to blood flow over the device or in the surrounding tissue. Thus more sophisticated approaches are required to accurately represent real world scenarios and better define conditions under which patients with implanted devices can be safely exposed to MR imaging.

 

And more sophisticated approaches are precisely what we are working on. AltaSim is fortunate to be working with people whose aim is to help bring real answers full of factual information by utilizing computational modeling and multiphysics simulation to serve not only the biomedical industry, but also the treating physician and the patient. These efforts align with our motto, “Tomorrow’s Technology Today” and we are excited about the real life possibilities for all involved. Your comments and questions are always welcome.

 

References
1. Reuters 2011 from Chan, Journal of the American Medical Association, July 5, 2011
2. MPMN, Volume 27, No. 7, 2011
3. U.S. Markets for Peripheral Vascular Stents, MedTech Insight Report #A254, 2011
4. OECD Health Statistics 2014 – Frequently Requested Data
5. Medtronic web page
6. FDA Public Health Notification: MRI-Caused Injuries in Patients with Implanted Neurological Stimulators, May 2005
7. MRI-Related Death of Patient With Aneurysm Clip, November 1992
8. U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Medical Device Report (MDR)
9. U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Manufacturer and User Facility Device Experience Database, MAUDE
10. Cardiovascular Catheters and Accessories, MRISafety.com

 

 

COMSOL Workshops

COMSOL_Certified_Consultant

COMSOL Workshops

Over the years, our association with COMSOL has grown from one of novice user to avid user to COMSOL Certified Consultant to experts who provide Training Classes to help new and existing users maximize their use of COMSOL Multiphysics. Last fall, we had several conversations with COMSOL about a possible new association. As a result, this year we have been visiting Ohio cities with COMSOL staff members helping to conduct monthly free COMSOL Workshops.

 

Each workshop includes an overview of COMSOL in the morning during which AltaSim staff provide demonstrations of multiphysics modeling and discuss the functionality of different modules of COMSOL Multiphysics based on our real-world experience. The afternoon portion of each workshop focuses on a specific physics that changes each month as we make our way around the state. Some attendees stay for only the morning session and some stay for the entire day depending on topic and interest. So far, we have found four basic reasons people attend:

 

  1. You may be looking at COMSOL for the first time wondering if it is the kind of tool that can help
  2. You may already be a casual user needing some basic help
  3. You may be working through a free two-week trial trying to solve a specific problem
  4. You may be very adept at using COMSOL but still looking to grow your proficiency

 

In January, Kyle and Josh started our Ohio workshops in Independence focusing on Heat Transfer & Structural Mechanics. In February, Kyle and Luke were in Columbus covering Heat Transfer & Fluid Flow. In March, Kyle and Josh went to Toledo and taught on Heat Transfer & Structural Mechanics. This month, Kyle and Sergei were in Fairborn teaching about the App Builder & Aerospace Applications.

 

Below are links for the workshops we will be conducting over the next two months.

 

Cincinnati, OH May 21, 2015 – App Builder & Biomedical Workshop
http://www.comsol.com/events/id/45911

 

Independence, OH June 4, 2015 – App Builder & Biomedical Workshop

http://www.comsol.com/events/id/46351

 

As founding members of the COMSOL Certified Consultants program we combine our expertise in COMSOL Multiphysics® and our ability to extend its functionality with our in-depth knowledge of physics, mechanics, computational science and real world processes to a wide range of applications. Our desire in these free workshops is to help each attendee discover how together AltaSim and COMSOL can help them solve their challenging design problems in new ways that will have an impact on their business.

We will provide additional information about upcoming workshops through our monthly email newsletter. If you would like to receive this information directly in your email, then subscribe by entering your name and email address in the “Newsletter Registration” section on the right side of the webpage.

 

Webinar: Simulation of Thermal-Structure Interaction – July 17th

Simulation of Thermal-Structure Interaction – July 17th

 

On Thursday, July 17th, Mechanical Engineering and COMSOL will give a free webinar on “Simulation of Thermal-Structure Interaction.”
Details and registration are available below.

 

Live Presentation – Thursday, July 17th, 2014, 2:00pm EDT
http://comsol.com/c/17br

 

Speakers:
Kyle C. Koppenhoefer from AltaSim Technologies
Shankar Krishnan, Applications Engineer, COMSOL

 

Multiphysics simulation can be used to model thermal-structure interaction and involves coupling structural analysis and heat
transfer. One application includes simulating thermal expansion in order to analyze thermally induced stresses in electronics, MEMS
devices, and machineries. In this webinar we will cover related topics, including thermal and mechanical contact. We will explore
features of COMSOL Multiphysics(R) that are needed for solving thermal-structure interaction problems. The webinar will include
a live demonstration showing how to set up such a problem, and will conclude with a Q&A session.

 

For more information and to register, visit:     http://comsol.com/c/17br

 

If you are unable to attend the live event, register and you’ll receive notification once the recorded version is available.

 

Tomorrow’s technologies lend themselves to a growing need for multiphysics simulation, and both COMSOL and AltaSim Technologies are committed to helping more and more people become skilled in the use of COMSOL Multiphysics(R). We have just updated our Training Calendar for the next six months and invite our readers to check out and register for upcoming classes as an investment in the future of simulation. Excellence is not an accident. We want to help you get there.

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