Travel Trailer Analysis in ANSYS Discovery

ANSYS Discovery is a wonderful tool for fast and first look structural, fluid flow, and thermal simulations. Discovery gives us the ability to modify geometry very quickly within the interface and to add or remove features to view realtime simulation reactions. This allows us to quickly iterate, explore design changes, and better understand interaction between our design and the environment. Today we are going to be investigating the pressure profile on the exterior of a travel trailer being pulled behind a truck down the highway. You can watch the whole simulation on this video.

Truck and Trailer with velocity streamlines

In this analysis we are using a 2018 Chevy Silverado 2500 model pulled from GrabCAD with a generic 25 foot travel trailer. Based on described experience we’ve noticed that the roof and sidewalls of a moderately sized travel trailer seem to bow outwards at highway speeds near the front of the trailer.

The first thing to do is to put this model in an enclosure and prescribe a flow condition at the inlet and a pressure boundary at the outlet. Modeling the truck/trailer combo at a speed of ~55 mph (25 m/s) confirms that there is suction (negative pressure) present in these key areas:

Negative Pressure: Truck and Trailer in 25 m/s airflow, -500 Pa isosurface

While the actual roof and sidewall separating could be attributed to poor manufacturing processes we wonder if there could be a design change to minimize negative pressure/suction. One idea would be to incorporate some sort of turbulator to break up the laminar flow. I’ve seen turbulator tape in a zig-zag pattern used in aviation for this specific purpose so we’ll try recreating the travel trailer equivalent and see how it goes.

I started with a zig-zag pattern about 4″ tall on top of the trailer to see if I could “pop the bubble”

This did have the intended consequence and it was curious to see how much impact the turbulator on top of the trailer had on the negative pressure at the sidewall of the trailer:

The next thing I wanted to try was moving the turbulator forward or backward to see the effects. Moving the turbulator towards the aft of the vehicle has limited effects but moving it to different locations within the suction “bubble” seems to effect our -500 Pascal isosurface:

This would seem to indicate the presence of a “sweet spot” for turbulator location that merits further research in either the “Analyze” mode within Ansys Discovery or within Ansys Fluent.

Before I hang up my coat I’d like to investigate one alternate design that I’ve seen more often in automotive applications. I’m going to try adding vertical pillars and see how that goes:

We can easily change the height and position of the pillars to see the resultant effects on the pressure isosurface. The pillars also have a significant effect on the suction bubble but I notice that it has less effect on the suction on the sides of the trailer.

Using Discovery we can quickly and easily iterate on designs, get a first-view of the physics, and determine which change or design merits further investigation. In this analysis we can see that there is most definitely a suction profile at the front of a generic travel trailer. If the suction proves damaging we can see that there are several design changes which will help to mitigate this effect.

For more information on ANSYS Discovery please reach out to info@padtinc.com.

If you would like to play with the models themselves, you can download a zip file with all three models here.

All Things Ansys 082: High Frequency Updates on Ansys 2021 R1

 

Published on: February 26th, 2021
With: Eric Miller & Aleksandr Gafarov
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by PADT’s Electronics Application Engineer Aleksandr Gafarov for a look at what’s new in this electromagnetics release.

When it comes to high frequency electromagnetics, Ansys 2021 R1 delivers a plethora of groundbreaking enhancements. Ansys HFSS Mesh Fusion enables simulation of large, never before possible electromagnetic systems with efficiency and scalability.

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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Alternating Stresses in Ansys Mechanical – Part 2: von Mises Stress

Editor’s Note:
The following PowerPoint is from one of PADT’s inhouse experts on linear dynamics, Alex Grishin.

One of the most valuable results that can come from a harmonic response analysis is the predicted alternating stresses in the part. This feeds fatigue and other downstream calculations as well as predicting maximum possible values. Because of the math involved, calculating derived stresses, like Principal Stresses and von Mises Stress can be done in several ways. This post shows how Ansys Mechanical does it and offers an alternative that is considered more accurate for some cases for von Mises. Part 1 covers how to do the same for Principal Stresses.

Alternating_vonMises_Stress

Alex also made this zip file that contains updated macros, an example Mechanical database, and a spreadsheet:

General Interface & Performance Updates in Ansys 2021 R1 – Webinar

Ansys 2021 R1 delivers significant improvements in simulation technology together with nearly unlimited computing power to help engineers across all industries reimagine product design and achieve product development goals that were previously thought to be impossible.

Ansys Mechanical delivers features to enable faster simulations, easier workflows, journaling, scripting and product integrations that offer more solver capabilities. Within this new release, interface and performance capabilities have been enhanced to offer greater ease of use and overall efficiency in nearly every circumstance. 

Join PADT’s Simulation Support Manager and Ansys expert Ted Harris, for an overview of what updates in this release best energize this tool, such as enhancements made to:

• Solution History

• Fluid Network Creation

• Circuits

• GPU & Solvers

• And much more

Register Here

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High Frequency Updates in Ansys 2021 R1 – Webinar

Whether leveraging improved workflows or leading-edge capabilities with Ansys 2021 R1, teams are tackling design challenges head on, eliminating the need to make costly workflow tradeoffs, developing next-generation innovations with increased speed and significantly enhancing productivity, all in order to deliver high-quality products to market faster than ever.

When it comes to high frequency electromagnetics, Ansys 2021 R1 delivers a plethora of groundbreaking enhancements. Ansys HFSS Mesh Fusion enables simulation of large, never before possible electromagnetic systems with efficiency and scalability. This release also allows for encrypted 3D components supported in HFSS 3D Layout for PCBs, IC packages and IC designs to enable suppliers to share detailed 3D component designs for creating highly accurate simulations.

Join PADT’s Lead Electromagnetics Engineer and high frequency expert Michael Griesi for a presentation on updates made to the Ansys HF suite in the 2021 R1 release, including advancements for:

  • Electronics Desktop
  • HFSS
  • Circuits
  • EMIT
  • And Much More

Register Here

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Press Release: Ansys Elite Channel Partner and Stratasys Diamond Channel Partner, PADT Announces Jim Sanford as Vice President of Sales & Support

The Sales and Support team at PADT is the group that most of PADT’s customers interface with. They sell world-leading products from Ansys, Stratasys, and Flownex and then provide award-winning support long after the initial purpose. The team has grown over the years and has plans for even more growth. To help make that happen, we are honored to have Jim Sanford join the PADT family as the Vice President of our Sales & Support team.

Many of our customers and partners know Jim from his time with industry leaders Siemens, MSC, Dassault Systems, and NextLabs, Inc. He brings that experience and his background as a mechanical engineer before he entered sales, to focus PADT on our next phase of growth. He also fit well in PADT’s culture of customer focused, technical driven sales and support.

Our customers have a choice of who they purchase their Ansys multiphysics simulation, Stratasys 3D Printers, and Flownex system simulation software from, and who delivers their frontline support. We know with Jim leading the team, even more companies will make the choice to be part of the PADT family.

The official press release has more details, and can be found at these links or in the test below.

Press Release: PDF | HTML

Want to have a conversation about your Simulation or 3D Printing situation? Contact PADT now and one of our profesionals will be happy to help.


Ansys Elite Channel Partner and Stratasys Diamond Channel Partner, PADT Announces Jim Sanford as Vice President of Sales & Support

Sanford Brings a Wide Range of High-Profile Leadership Experience Across Technology and Aerospace and Defense Sectors to his New Position

TEMPE, Ariz., February 11, 2021 PADT, a globally recognized provider of numerical simulation, product development, and 3D printing products and services, today announced the addition of Jim Sanford as vice president of the company’s Sales & Support department. In his new position, Sanford is responsible for leading the increase of sales and customer support for a range of best-in-class simulation and additive manufacturing solutions. Sanford reports to Ward Rand, co-founder and principal, PADT.

“In the last few years, PADT has expanded across the Southwest, adding new expertise and technologies to our product and service offerings,” said Rand. “Jim is a valuable addition to the team and will be instrumental in sustaining PADT’s growth across the region. His leadership, experience, and knowledge of the industry will allow us to increase the pace of expansion and bring our solutions to serve new and existing customers in deeper and more impactful ways to their businesses.”

After a comprehensive search, Sanford proved to be the most experienced and capable leader to take on the vice president role. He will focus on providing visionary guidance, strategy, and tactical direction to the department. His responsibilities include refining the company’s sales team structure, recruiting, hiring, training, managing for profitable growth, and leading the support team to ensure an optimal customer experience for their use of Ansys, Stratasys, and Flownex products.

Prior to joining PADT, Sanford held business development and engineering positions in a diverse range of aerospace and defense, modeling and simulation, and software companies. His 30-year career span includes executive leadership roles at Siemens, MSC, and Dassault. Most recently he served as the VP for NextLabs Inc., a leading provider of policy-driven information risk management software for large enterprises, and the VP of Business Development for Long Range Services, where he was engaged in the development and testing of various classified items for the U.S. Department of Defense. He holds a bachelor’s degree in Mechanical Engineering from the University of Arizona, with emphasis in materials science and physics.

“PADT is a well-respected brand well-known for its product knowledge, customer-centric approach, and expertise,” said Sanford. “My career has been defined by my ability to take technology-focused companies to the next level of success, and I’m thrilled to join PADT and help continue its expansion by supporting highly innovative customers.”

PADT currently sells and supports the entire Ansys product line in Arizona, California, Colorado, Nevada, New Mexico, Texas, and Utah as an Ansys Elite Channel Partner. They also represent all Stratasys products in Arizona, Colorado, New Mexico, Texas, and Utah as a Diamond Channel Partner and are the North American distributor for Flownex.

To learn more about Sanford and PADT’s products and services, please visit https://www.padtinc.com/products/

About PADT

PADT is an engineering product and services company that focuses on helping customers who develop physical products by providing Numerical Simulation, Product Development, and 3D Printing solutions. PADT’s worldwide reputation for technical excellence and experienced staff is based on its proven record of building long-term win-win partnerships with vendors and customers. Since its establishment in 1994, companies have relied on PADT because “We Make Innovation Work.” With over 90 employees, PADT services customers from its headquarters at the Arizona State University Research Park in Tempe, Arizona, and from offices in Torrance, California, Littleton, Colorado, Albuquerque, New Mexico, Austin, Texas, and Murray, Utah, as well as through staff members located around the country. More information on PADT can be found at www.PADTINC.com.

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All Things Ansys 081: Meshing & UI updates in Ansys Fluent 2021 R1

 

Published on: February 8th, 2021
With: Eric Miller & Sina Ghods
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by PADT’s Senior Simulation Support & Application Engineer and fluids expert Sina Ghods for a look at what’s new in this release.

For fluids simulation in this release, products can be designed faster than ever before, thanks to major physics and productivity enhancements that build upon the tool’s ​already powerful workflow and meshing capabilities.

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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Workflow & Meshing Updates in Ansys Fluent 2021 R1 – Webinar

From small to mid-sized companies to global organizations, companies of every size seek new ways for pioneering breakthrough innovations that are safer and more reliable to win the race to market.

Ansys 2021 R1 delivers significant improvements in simulation technology together with nearly unlimited computing power to help engineers across all industries reimagine product design and achieve product development goals that were previously thought impossible.

For fluids simulation in this release, products can be designed faster than ever before, thanks to major physics and productivity enhancements that build upon the tool’s ​already powerful workflow and meshing capabilities. Join PADT’s Senior Simulation Support & Application Engineer and fluids expert Sina Ghods for a look at what’s new in this release including: 

• Fluent User Interface Updates

      • Meshing Workflow Advancements

      • Combustion Applications

      • Turbomachinery Applications

      • Battery Modeling Applications

      • Multiphase and DPM Improvements

If this is your first time registering for one of our Bright Talk webinars, simply click the link and fill out the attached form. We promise that the information you provide will only be shared with those promoting the event (PADT).

You will only have to do this once! For all future webinars, you can simply click the link, add the reminder to your calendar and you’re good to go!

All Things Ansys 080: 2020 Wrap-up & Predictions for Ansys in the New Year

 

Published on: January 25th, 2021
With: Eric Miller & PADT’s Ansys Support Team
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by the simulation support team to look back at the past year of Ansys technology and make some predictions regarding what may happen in the year to come.

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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All Things Ansys 079: The State of Simulation for Additive Manufacturing

 

Published on: January 11th, 2021
With: Eric Miller & Brent Stucker
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by Brent Stucker, the Director of Additive Manufacturing at Ansys to discuss the innovative capabilities of the Ansys additive suite of tools and it’s impact on the effectiveness of 3D printing for manufacturing and design.

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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Discussions on the Past, Present & Future of Optimizing Topology for Manufacturing – Webinar

Traditional design approaches don’t make the most of new manufacturing methods, like additive manufacturing, which are removing design constraints and opening up new possibilities. The optimal shape of a part is often organic and counterintuitive, so designing it requires a different approach.

Topology optimization lets you specify where supports and loads are located on a volume of material and lets the software find the best shape.

Kick off the year by learning about one of the most exciting advancements in modern design and manufacturing. Join experts from PADT and nTopology for an interactive roundtable discussion on the ins and outs of topological optimization.

Register Here

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Understanding Honeycomb Structures in Additive Manufacturing – Three Papers from ASU and PADT

PADT is currently partnering with Arizona State University’s 3DXResearch group on exploring bio-inspired geometries for 3D Printing. As part of that effort, one of our engineers involved in the project, Alex Grishin, PhD, was a co-author on several papers that have been published during this project.

Below is a brief summary from Alex of each article, along with links.


An Examination of the Low Strain Rate Sensitivity of Additively Manufactured Polymer, Composite and Metallic Honeycomb Structures

PADT participated in the research with the above title recently published in the open-access online journal MDPI ( https://www.mdpi.com/1996-1944/12/20/3455/htm ). This work was funded by the America Makes Program under a project titled “A Non-Empirical Predictive Model for Additively Manufactured Lattice Structures” and is based on research sponsored by the Air Force Research Laboratory under agreement number FA8650-12-2-7230.

Current ASU professor and former PADT employee Dhruv Bhate was the Lead Investigator and wrote the original proposal. Dhruv’s research interests involve bio-inspired design (the study of structures found in nature to help inform human design efforts) and additive manufacturing. Dhruv is particularly interested in the bulk properties of various lattice arrangements. While investigating the highly nonlinear force-deflection response of various additively manufactured honeycomb specimens under compression, Dhruv discovered that polymer and composite honeycombs showed extreme sensitivity to strain rates –showing peak responses substantially higher than theory predicts at various (low) strain rates. This paper explores and quantifies this behavior.

The paper investigates hexagonal honeycomb structures manufactured with four different additive manufacturing processes: one polymer (fused deposition modeling, or material extrusion with ABS), one composite (nylon and continuous carbon fiber extrusion) and two metallic (laser powder bed fusion of Inconel 718 and electron beam melting of Ti6Al4V). The strain rate sensitivities of the effective elastic moduli, and the peak loads for all four processes were compared. Results show significant sensitivity to strain rate in the polymer and composite process for both these metrics, and mild sensitivity for the metallic honeycombs for the peak load.

PADT contributed to this research by providing ANSYS simulations of these structures assuming viscoplastic material properties derived from solid dog-bone test specimens. PADT’s simulations helped provide Dhruv with a proposed mechanism to explain why INSTRON compression tests of the honeycomb structures showed higher peak responses (corresponding to classical ultimate stress) for these specimens than the solid specimens.


Bioinspired Honeycomb Core Design: An Experimental Study of the Role of Corner Radius, Coping and Interface

PADT participated in the NASA-funded research with the above title recently published in the open-access online journal MDPI (https://www.mdpi.com/2313-7673/5/4/59/htm ). This work was guided by former PADT engineer and current ASU Associate Professor Dhruv Bhate.  Professor Bhate’s primary research interests are Bio-Inspired Design and Additive Manufacturing. It was only natural that he would secure a grant for this research from NASA’s  Periodic Table of Life ( PeTaL) project. To quote from the website, “the primary objective…is to expand the domain of inquiry for human processes that seek to model those that are, were or could be found in nature…”

This paper focuses on the morphology of bee honeycombs found in nature –the goal being to identify key characteristics of their structure, which might inform structural performance in man-made designs incorporating similar lattice structures. To this end, the paper identifies three such characteristics: The honeycomb cell corner radius, the cell wall “coping” (a localized thickening of the cell wall at the mouth of each cell seen in a lateral cross-section), and the cell array “interface” (a zigzag pattern seen at the interface of two opposing, or “stacked” arrays).

Most of this work involved material testing and measuring dozens of natural honeycombs (most coming from various museums of natural history found in the United States) at ASU’s state-of-the-art facilities. PADT  contributed substantially by verifying and guiding tests with simulation using the ANSYS suite of software.


A Comparison of Modeling Methods for Predicting the Elastic-Plastic Response of Additively Manufactured Honeycomb Structures

PADT participated in this research found in the reviewed article published in Proceedings of the 29th Annual International Solid Freeform Fabrication Symposium – An Additive Manufacturing Conference.

Figure 14. (left) 2D plane strain model with platens connected to honeycomb with frictional contacts and (right) close-up of an individual cell showing the mesh size as well as corner radius modeled after experimental measurements

The lead investigator was current ASU professor and former PADT employee Dhruv Bhate, whose research interests involve Bio-Inspired Design (the study of natural structures to help inform human design processes) and Additive Manufacturing. In this research, Dhruv investigates discrepancies between published (bulk) material properties for the Fused Deposition Modeling (FDM) of ABS honeycomb structures. The discrepancies arise as substantial differences between published material properties, such as Young’s Modulus and yield stress, and those determined experimentally from FDM dog-bone specimens of the same material (which he refers to as “member” properties).

Figure 4. (left) Homogenization enables the replacement of a cellular material with a solid of effective properties, (right) which can greatly reduce computational expense when simulating engineering structures

PADT’s role in this research was crucial for demonstrating that the differences in base material characterization are greatly exacerbated in nonlinear compression simulations of the ABS honeycomb structures. PADT used both the manufacturer’s published properties, and the dog-bone data to show substantial differences in peak stress under the two assumptions.

https://www.scopus.com/record/display.uri?eid=2-s2.0-85084948560&origin=inward&txGid=a19776da6deb7846e12bc8f7573181ab

All Things Ansys 078: Optimization & Automation Updates in Ansys 2020 R2 – OptiSLang

 

Published on: December 14th, 2020
With: Eric Miller & Josh Stout
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by PADT’s Systems Support & Application Engineer Josh Stout for a discussion on how OptiSLang helps to increase the robustness and reliability of simulation, as well as a look at what new features are in the 2020 R2 updated version.

If you would like to learn more about this update, you can view Josh’s webinar on the topic here:

https://www.brighttalk.com/webcast/15747/458229

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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Optimization & Automation Updates in Ansys 2020 R2 – Webinar

Simulation is becoming an integral part of our customers’ product development processes, and new horizons await. By combining different physics into a multidisciplinary approach, phenomena can be investigated more holistically and optimized to a greater degree. Additionally, simulation processes can be standardized and shared across teams, allowing simulation novices to gain more direct access to simulation.

Time-consuming manual searches for the best and most robust design configuration can now be accelerated by adding state-of-the-art algorithms for design exploration, optimization, robustness and reliability analysis. Through the power of interactive visualization and artificial intelligence technologies, engineers and designers can gain a better understanding of their design and make the right decisions in less time.

The process integration and design optimization solution that enables all the above is Ansys optiSLang.

Join PADT’s Mechanical Application Engineer and Systems Expert Josh Stout for an exploration of this interconnected tool and what new capabilities are available in it’s 2020 R2 release.

Register Here

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All Things Ansys 077: Multibody Dynamics Updates in Ansys Motion 2020 R2

 

Published on: November 30th, 2020
With: Eric Miller & Jim Peters
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by PADT’s Senior Staff Technologist Jim Peters for a discussion on the new capabilities available within Ansys Motion 2020 R2. With an integration into Mechanical, users can take advantage of multi-use models resulting in substantial time savings.

If you would like to learn more about this update, you can view Jim’s webinar on the topic here:

https://www.brighttalk.com/webcast/15747/455203

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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