The PADT Blog

  • Simulating Electrical Windings: Solid or Stranded?

    In Ansys Maxwell, windings can be added in Eddy Current and Transient Solvers. There are two types of conductors when assigning the windings: Solid and Stranded. What is the difference?

    The Solid type considers the conductor as a solid part and therefore, the eddy current and AC effects will be taken into consideration. While the Stranded type assumes the conductor consists of infinite strands of tiny conductors and therefore, there is no eddy current inside the conductor.

    Now if there is no time-varying current or magnetic field in the model, will it be the same using Solid or Stranded? The answer is NO. Figure 1 shows a simple geometry of one-turn copper conductor. The cross-section is 1 mm by 1 mm and length of each edge is 100 mm. Assume the winding type is External and the circuit is shown below in Figure 2. The winding is connected to an external resistance (0.003 ohm) and the DC voltage source is 1 V.

    Fig. 1 – Geometry of the conductor
    Fig. 2 – Winding external circuit.

    The question will be: what is the current in the winding? Based on the physical geometry of the conductor, the conductor resistance can be calculated by R=ρ L/A, where L is the length of the conductor, A is the cross-sectional area and ρ is the resistivity of the copper material. The calculated conductor resistance is about 0.006872 ohm. The winding current will be different based on conductor type.

    • Solid type

    When the conductor is selected as Solid in ANSYS Maxwell, the winding resistance will be included while calculating the current. Therefore, the winding current will be:

    Note: if the winding resistance is changing, the winding current will also change.

    And the winding loss will be:

    The winding loss calculated by Ansys Maxwell is 70.57 W which is identical to the result above.

    • Stranded type

    When the conductor is selected as Stranded in Ansys Maxwell, the winding resistance will NOT be included while calculating the current. Therefore, the winding current will be:

    Note: the winding current is a constant no matter the winding resistance changes or not.

    And the winding loss will be:

    The winding loss calculated by Ansys Maxwell is 763.55 W which is identical to the result above.

    Conclusion

    1. The Solid type is needed if the AC effect is of interest.
    2. For Voltage winding type, the DC winding current and DC winding loss will be different for Solid and Stranded types. If the load resistance is much larger/smaller than the winding resistance, this difference can be neglected.
    3. If the user is using the Voltage source and doing the EM-Thermal coupling simulation, it requires more attention as the temperature rise will increase the winding resistance and therefore, decrease the winding current (as the voltage is fixed). In this case, users can either choose Solid or add an additional scaling factor in the material property to compensate for the current difference.

    If you would like more information related to this topic or have any questions, please reach out to us at info@padtinc.com.

  • All Things Ansys 090: Simulating Predictive Lung Modeling in a Rapidly Evolving COVID World

     

    Published on: June 14th, 2021
    With: Eric Miller & Jacob Riglin
    Description:  

    In this episode your host and Co-Founder of PADT, Eric Miller is joined by Jacob Riglin from Los Alamos National Laboratory to discuss simulation’s role in predictive lung modeling and experimentation in a rapidly evolving COVID world.

    Learn how Los Alamos used Ansys CFX to predict turbulence and flow structure through the lungs and analyze the impact COVID has on it, as well as patient response to various ventilators.

    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!

    Listen:
    Subscribe:

    @ANSYS #ANSYS

  • Setting up and Solving a PCB and Enclosure for Thermal Simulation in Ansys Icepak Electronic Desktop

    The thought of setting up and running a complex PCB and Enclosure thermal model was something that used to strike fear in the heart of engineers. That is no longer true. In this video, we step through the process of importing, setting up, and solving a PCB thermal simulation.

    https://youtu.be/daaOG3aaSL8

    If you have any questions or would like to learn more, please contact us at info@padtinc.com or www.padtinc.com.

  • Friday Flownex Tech Tips #6

    Creating Custom Fluids

    Occasionally glossed over, adding custom fluids is a fairly standard operation in Flownex that we don’t think about until it’s necessary. There are a couple of ways to do this which we’ll go over in today’s post. I am working in Flownex 8.12.7.4334.

    Creating a mixed fluid

    To create a mixed fluid we first need to create a folder for this fluid in our project database. This can be done in the charts and lookup tables pane by right clicking on “mixed fluids” and selecting “add category”. We can create our new fluid by right-clicking on the new folder and selecting “Add a new mixed fluid”. Note we can right-click and rename both the fluid itself and the containing folder.

    To define our new mixed fluid we double-click on the new mixed fluid to open the editor. Here we can add the components of our mixed fluids.

    Creating a new fluid from scratch

    To create a fluid from scratch we repeat the same process of creating a folder and creating a new fluid as above with the exception being that we’d complete these steps under the “Pure Fluids” category. Once this is done we’ll need to double-click or right-click > edit our from scratch fluid and enter in the fluid properties. Note for many properties we can define the relationship with pressure and temperature as constant (non-dependent), table, equation, or script.

    Importing a fluid

    To import a fluid we will follow the same steps of creating the folder under pure fluids. Now instead of right-clicking and adding new we will right-click and select “import”. Then we simply navigate to our desired fluid file and click “Ok”.

    Bonus Tips!

    • In the window where you define your fluid you’ll notice the “Test” button. This feature can be utilized to test created fluids to confirm properties against known properties for given pressures and temperatures.
    • We can also copy and paste fluids from the master database into the project database to give us a good starting point for creating similar fluids (or extending properties to higher/lower temps/pressures).

  • A PADT Engineer in King Attiball’s Court – Chapter 5

    There just is not enough engineer-focused fiction out there. Romance, Horror, Sci-Fi, Young Adult, Historical, Mystery, etc. They all do well, but they are rarely written for the engineers of the world.

    Here at PADT, we are all about undoing such injustices. We decided to brainstorm a story about an engineer who does simulation and 3D Printing and ends up on an adventure. We hope they will find some mystery, some science fiction, and some horror. Maybe even a little romance. To develop the characters and the plot we all got on an MS Teams meeting and blocked it out. It was a lot of fun. That turned into an outline, that will turn into a chapter every month.

    We hope you enjoy the result as much as we enjoyed dreaming the journey up.

    It should be noted that every character in this story is completely made up. Sometimes we steal some names from real people as a shoutout to them, but that is about it. PADT does not have a basement or a fancy cluster in one. Everything is made up. Well, almost everything. We do have a stack of furniture in the back of shipping and receiving.


    Chapter 1: Batch Submission | Chapter 2: New Friends | Chapter 3: Like an Owl | Chapter 4: Off to Sea

    Chapter 5
    City on the Nile

    Sailing in a Phoenician trading ship was nothing like a Disney Cruise. Ash quickly found a spot in the rear where she could wrap her arms around a piece of railing to keep herself from being launched over the side while she emptied what little was left in her stomach into the blue Mediterranean.  At first, the oarsmen had laughed when they heard her retching. Then, after several hours of obvious misery, they shouted out suggested remedies and appeals to various gods, many Ash had never heard of. 

    Eventually, the sun began to dip closer to the horizon, and Duzi gave the order to head back towards shore.  Verihbitt had been sitting in silence with Ash for some time, occasionally offering honeyed water or a wet rag to put on her forehead. 

    She said, “Tomorrow, you will feel better. And in a day or two, you will be walking about the deck like an old trader.” She gently stroked Ash’s hair and asked, “do you usually get sick when you sail? When you came to Sur from your land, that must have been a very long journey and on rougher seas than this?”

    Ash was startled by the question. The answer she wanted to give was, “the quantum temporal thinga-ma-jigger that tossed me across the time-space continuum does not seem to cause motion sickness.”  Then she realized coming up with a Phoenician word for quantum was the least troubling aspect of that statement.

    Instead, she said, “I am better at traveling by land. But will get used to it.”

    Verihbitt looked at Ash for some time and said, “I can tell there is much you chose not to tell me.  I understand that.  However, when you agreed to come on this mission, you agreed to share our danger. And if we are all going to survive, let alone succeed, we have to be honest with each other.”

    The coastline was getting nearer, and Ash searched it for the correct response. Her heart told her that Verihbitt was right.  Hiding so much about who she was could be dangerous for everyone. The growing trust between the two women was also something that Ash was beginning to cherish. Alone in the past, the connection was becoming critical to her sanity.

    Weighing her options, she decided to try and shade the truth with what she understood of the world she found herself in.

    Ash asked, “What are your thoughts on the gods?”

    “Oh, them. We have a difficult relationship.” She laughed. “I do my part. I leave the building of temples and most of the sacrifices to my father and uncle. Most of the gods seem to stay out of my business, and I try to stay out of theirs. Now and then, I think a few play with me.”

    She stopped, turned to look at the setting sun, and added, “especially when it comes to men. Maybe I should make some of my own sacrifices.” 

    This hint at Verihbit’s personal life was fascinating, and Ash wondered if it involved Takaa. She avoided the temptation to go down that road and instead contemplated how to describe her journey in a way that Verihbit would understand.

    “The truth is, this is my first voyage by ship.  I did not sail or travel on land to get here. I am still unsure what exactly happened. In my land, I made a request to what I thought was one of our minor gods, who we call FLUENT. It seems that two other far more powerful gods saw my request and decided to send me here.”

    “I do not know the gods of your land, but they sound like ours.  They like to meddle and mix things up. Sometimes I think they are simply bored and do such things for entertainment. Which gods were they? Maybe we have a name for them.”

    Ash was relieved.  So she continued, embracing the mental translation of physics to mythology.   “Yes, I think you are right. One of these gods is Quanta. She controls how very, very small things behave.  She is the queen of randomness, and you can never get a yes or no answer from her. And you never know what she has decided till you look closely at what she has done. Before that, she often appears to be doing two different things at the same time”

    “This sounds like Hadad, our god of storms and chaos?”

    “I think that is different. We call Hadad Entropy. But you will recognize the other god that sent me here, Aion. We call him Temporal. The god of time.”

    She stopped and looked at Verhibitt.  This complicated woman had taken her, a stranger, into her life.  Ash was not sure what she was afraid of. Maybe it was being called a witch and having a crowd call for her to be burned. Perhaps everything was happening too fast.

    Veribitt smiled at Ash, and it was not that different from the beauty of the sun setting over her shoulder.

    This mythical version of events was starting to make sense to Ash as well. Attempting to understand how a computer system coupled to a virtual reality room sent her through time and space hurt her head. Blaming it on a cable of temperamental gods had its appeal.  Ash decided to keep going.

     “You see, these gods did not just move me across the world. They moved me across time.” She paused to let it settle. “Verhibitt, I come from the future. And not just tomorrow or next harvest season. I journeyed here from thousands of years in the future.”

    Ash waited to hear her friend’s response, watching the white beach move closer as the oarsmen continued their steady rowing, their rhythmic splashes meshing with the sound of waves to form a soothing song that helped settle Ash’s anxiety.

    Eventually, Verihbitt stood and shrugged her shoulders.  “That makes no sense to me, but who am I to question the gods. I am just thankful they brought you to us. And I chose to believe they did it in answer to the sacrifices and prayers from all those priests the King pays for.  Yes, that does make sense. You were sent here to help us.”

    She leaned down and gently kissed the top of Ash’s head.  “When we arrive in Egypt, we will find a temple for each of your two gods and make a sacrifice of thanksgiving. No harm in bribing them. But that is days away. Now it is time to prepare to beach the ship and make camp.”

    Behind Ash, the crew and passengers rushed around the deck. The wind was now behind them, and several of the oarsmen opened the sail. Others stowed the oars. The ship surged forward, riding the wind and waves. 

    In a rush that threatened to turn Ash’s stomach inside out once again, a gust pushed the ship forward and onto the beach. Ash felt the ship slide across the sand and settle with a pronounced tilt toward the side she still clung to. Without hesitation, she climbed over the railing and jumped down into the sand.  She wasn’t sure if the overwhelming relief she felt was because the constant rocking had stopped or because she was no longer hiding her secret from Verihbitt. 

    Drained from a day of sea sicknesses, Ash found a place to sit in the sand as the crew set up around an existing fire pit.  Some of the oarsmen went into the scrubby forest that started just past the beach, while others set up tents and camp tables in the setting sun.

    The night was Ash’s most enjoyable since arriving.  She didn’t know what she was eating or where it had come from on the small ship. She only knew it tasted good. Alim insisted she drink two bowls of wine that were not watered down. As the others talked and laughed, Ash felt herself drift off to sleep.

    The following morning Ash stalled as long as possible before boarding the ship, finally walking up the thin plank onto the deck as the tide was starting to lift the keel off the sand. Fearful of another day of seasickness, she took up her position at the railing.  Thankfully, nausea never came, and she soon joined the other passengers on the forward deck under a striped tent that kept both the sun and the wind away.

    Duzi, Verihbitt, and Mnihh’dm were huddled together, whispering and planning.  So Ash found a pillow next to Alim.

    He looked up from the papyrus scroll he was reading and said, “Good morning, my lady. I see you have your sea legs today. That is good.  We were worried that this would be a long voyage for you.”

    “Thank you, Alim. Yesterday was difficult, but today I feel almost normal. As long as there are no storms and the swells stay small.”

    “Duzi had the men capture some birds when we landed, and he sacrificed them to this morning, asking for smooth sailing.  There is not much else we can do.”  He went back to reading his scroll.

    Before too long, Ash became incredibly bored.  Since middle school, she had had a phone in her hand. A tool that connected her to everyone she knew and an endless stream of videos, social media posts, and articles. Until now, Ash had been dealing with one crisis after another. Now, under this tent as the ship slowly made its way south, she began to panic. She saw her backpack on a pile of supplies in the corner of the tent. She walked over, removed her phone from the front pocket, and held it to her chest.

    In English, she said, “This is just stupid. Maybe gramma was right. Maybe I am too attached to this thing.” 

    Under her backpack were the supplies she had hastily gathered from the market before they departed. 

    She felt a zing in her brain as she called across the tent, “Alim! Want to help me build a –“ there was really no good word in ancient Phoenician for battery –  “a lightning jar?”

    The idea of building anything intrigued Alim.  Something as magical as a jar full of lightning had the older man behaving like an eager schoolchild.  He was full of questions while they gathered the raw materials on the deck before them. 

    Ash said, “Maybe I should draw a picture. Do you have something I can draw on?” 

    Alim dashed up and ran to his supplies, returning with a wooden plank and sharpened pieces of charcoal.  “I have not clay or papyrus.” He said. “I use this board to make my notes, and then I have a scribe put it down on something that lasts longer.”

    “This will do just fine,” Ash said.

    She placed the flat board on her lap and picked up a piece of charcoal, saying, “This is the clay pot.”

    She drew a cross-section of the clay jar, with a neck and an opening on the top.

    “And this is the iron rod in the center.”

    She sketched a thick line in sticking out the top and down to almost touching the bottom. 

    “Next is the copper cylinder,” she said. She rummaged through the charcoal pieces till she found a gray one. 

    “And this is this is the linen we will use to keep the copper from touching the iron and hold it up at the bottom.”

    She then picked up the black charcoal again and drew a wavy line across the top. Two lines for the wires attached to the copper and iron, and a + and – on each wire.

    “Then we will fill it with the fruit juice.”

    She showed it to Alim, and he studied it closely.  He then asked, “You want to keep the fruit juice away from the space between the copper and the iron?”

    Ash looked at the sketch. The linen at the bottom would keep the liquid from moving freely between the two electrodes.

    “You are right, “ she said, and used her thumb to smudge away the linen at the bottom. Then in English, “this is why we do design reviews.”

    For the rest of that day, they huddled around the small stone anvil at the bow of the ship, trying to make the copper blocks they had into a sheet they could turn into a cylinder.  It did not go well.  As soon as they pounded it thin enough, it would tear.  Or when they thought they had a good enough sheet, it ripped when they tried to roll it around a broken piece of oar they were using as a pattern.

    The elderly scholar and the young engineer were so engrossed by their task that they were shocked when the ship slid onto a beach.  Duzi and Verihbitt were standing next to the pair, laughter in their eyes.

    Duzi said, “We are putting in early today. The coast between here and the Nile delta is not safe. You two can continue your attempt to be artisans once we set up camp.”

    As he talked, he picked up another piece of rounded wood from the broken oar and jabbed it into a pot of sand sitting next to the anvil.

    Ash rushed towards him, put her arms around his neck, and kissed him on the cheek

    Ash said, “You are brilliant, Duzi. I was trying to form the copper cylinder. I should have been casting it.”

    She pecked him on the cheek again before realizing that Duzi’s face was bright red and everyone around them was utterly silent. She also became aware of how warm his body was and how firm his shoulder and neck muscles were.  Reluctantly, she let go and took a few steps back from him.

    “I am sorry.  When I figure something out, I get very excited.”  In English, she added, “I’m glad there is no HR here.”

    Once camp was set up, Ash and Alim built a small fire and placed copper in a stone crucible which they set above the growing flames. They also dug a deep, round hole and placed the wooden rod in the middle.  While the copper melted, Verihbitt, Mnihh’dm, Takaa, and Duzi formed a circle around the improvised casting facility. One of the oarsmen also joined them.

    When the copper looked fully melted, Alim used long iron tongs to lift the cup from the fire and pull the molten copper into the hole around the wood. Flames leaped up from the wood. Everyone gasped and took a step back. Once the cup was empty, the oarsman stepped forward and tossed sand on the burning wood.

    He took the tongs from Alim and said, “You know, old man, I am the ship’s maker. All you had to do was ask, and I can build anything from wood or metal. Go have your meal.  I’ll pull it out when it cools.”

    Ash felt embarrassed.  Of course, the ship would have someone on the crew who could make new tools and repair broken ones on their journey. At the same time, she was glad she had not known.  Making this part had been so much fun.

    The group walked to the tents and the smell of dinner.  Ash realized Alim was shuffling his feet in the sand, his head bowed.  She stopped and waited for him to catch up.

    “It is just fine,” she said. “I always wanted to make something that way. I really enjoyed our day.” She leaned over and kissed him on the cheek before dashing ahead to join the group.

    Ash slept well that night.  The next morning, as soon as the oars touched the water, she and Alim were at their shipboard workbench assembling her battery. The rest of the passengers joined in when it was time to squeeze the citrus.  Working as a team, the steady rowing marking their time, the morning past swiftly.

    After a brief break for lunch, she returned to their invention to try it out. Taking her spare charging cable from her backpack, she cut off the large USB connector and pulled the wires out of the insulation.  Trying to remember which ones were the power lines, she wrapped one around the rod and one in a hole she punched in the cast copper.  She then carefully poured the juice in, then lowered the copper cylinder and iron rod assembly down, pushing till the linen wrapped around the top of the copper part wedged into place.

    Not knowing how else to test it, she placed the lightning connector in her mount. 

    “Ouch!” she yelled.  And then began to laugh. “My friends, with your help, we have lightning in a jar.”

    Everyone wanted to try the device, delighted in the shock it delivered to their mouth.

    Once everyone had given it a try, she said, “Thank you all for your help. Now I need to see if it works with my –,“ she had to come up with a name for her phone.  “My special tablet.” That sounded good to her. She went on. “Given to me by one of our minor gods, Stevejobs.”

    Pleased with her inside joke, Ash headed to her backpack to get her phone. Halfway there, she heard the lookout yell, and what he said stopped her dead in her tracks.

    “Pirates!”

    She looked aft and saw the lookout pointing into the wind.  Turning to see what he was pointing at, Ash could see two ships upwind from them, large sales open to catch the wind. 

    Duzi yelled, “Turn to put the wind behind us, drop the sail.” The crew leaped into action.  Ash had to sit when the tiller was thrown to the side, and the deck leaned so far that the railing touched the water.  She heard the sail drop and felt the ship leap forward as the wind pushed to ship ahead.

    The two ships behind them were thinner and had more oars and larger sails. The oarsman rowed in two teams.  One keeping a steady pace while the other group rested and drank water.  Even with their strenuous effort, the two perusing ships continued to grow in size as they came closer.

    With worry on his face, Duzi told the passengers, who had all moved to the bow of the ship, “We won’t be able to outrun them.  We will have to turn and fight.”

    He gave a single command, “four!” to the oarsmen.  As one, they lifted their oars from the water and started to count with the same rhythm they had used to row. 

    One, two, three, four.” On four, they all stowed their oars.

    With the next four, they stood and faced their benches. At the end of every count, as one, they made what was obviously a well-rehearsed move.  First, they lifted the top of the benches, Then they removed shining armor.  In three counts, they had all put the armor on and lifted bright helms onto their heads.  Next, they remove spears and bows from the storage area beneath the benches.

    They counted to four one last time, then turned to face the left side of the boat, bows raised. 

    Ash heard Takaa say, “I actually feel sorry for those pirates. They have no idea who they are attacking.”

    Duzi shouted, “One!”

    The helmsman pushed the tiller arm slightly to the right, veering the ship at an angle slightly away from the pirate vessels that were now close enough for Ash to see faces.

    “Two!”

    Ash lost her balance as the ship turned sharply to the left. The wind was no longer behind them, and their forward momentum was spent. They sat dead in the water, their left side facing the attackers.

    “Three!”

    A loud twang of bows preceded a rain of arrows that fell on each ship. Ash could tell that some had landed because many of the oars had stopped moving.

    “Four!”

    The two black ships were now close, and those aboard who had not been hit by arrows fell to well-aimed spears. 

    The next five minutes were complete chaos.  When the ships were close enough, the remaining pirates boarded. But none of them made it very far. They were dropped by arrow, spear, or short sword if they did get close enough.  Ash was no expert, but she could tell that the muscular men who had rowed their ship for three days were no galley slaves. They were well-trained and seasoned soldiers who dealt death with casual professionalism.

    Through the entire battle, Takaa guarded the passengers with his sword drawn. But they were never in any real danger.  Duzi had joined the fray, directing the soldiers as they pushed forward. Eventually, they jumped over to the pirate ships. 

    When the sound of battle stopped, Ash heard Duzi yell, “One!”

    In answer, the soldiers responded with vigor and abandon that can only come from realizing that they had survived another battle. “two, three, FOUR!”

    Ash felt Alim’s thin hand rest on her shoulder and squeeze.  He said, “It can be overwhelming, no matter how many times you see it.”

    The world was spinning for Ash. She had certainly seen war in movies, even played at it with her friends. But CGI effects, video game gore, and foam-covered wooden swords did not prepare her for the amount of blood, the sounds of flesh being sliced, or the pitiful crying of the dying.  The encounter in Verihbitt’s garden, her first experience with the brutality of hand-to-hand contact, did not soften the mental blow of seeing the compliment of two ships methodically slaughtered in front of her.

    Alim said, “Come, let us retire to the tent.”

    Ash was asleep, collapsed into the fetal position on a large pillow before the soldiers had returned to their benches to row them on to Egypt.

    They spent the next night on the ship, anchored in one of the many small rivers in the Nile delta.  Ash stayed in the tent the next day as they rowed through the maze of the delta.  She could only see green reeds and muddy water through the opening of the tent. 

    When her friends gathered for the mid-day meal, she joined them around dried fish and olive platters.  Their simple chatter about things that were not important brought her out of her shock. By the end of the meal, she was laughing and talking with them. However, inside she was still dazed.

    When the meal was done, Duzi asked, “Would you like to see something amazing?”

    “Yes, I could use that.”

    “Good, come with me. You will only see this for the first time, once in your life.”

    He led her out of the tent and to the very front of the ship.  The channel there were in was wider and full of small boats and a few merchant ships.  Low hills blocked the view in front of them.  To the sides, green fields lined both sides of what, Ash realized, must be the Nile river itself.

    Ash said, “It is beautiful.”

    “Wait, this is nothing.” Said Verihbitt

    The rest of the group had joined them. A strong breeze pushed up the river, and she could hear the oarsmen strain against the current and the wind. The ship dodged a group of fishermen who were casting large nets into the water and hauling them back onto their small boats, bursting with wriggling fish.

    They rounded a gentle bend in the river, and Ash gasped in amazement.

    In front of the ship, amongst a vast complex of colorful buildings, a gleaming white pyramid rose up towards the sky.  It was the Great Pyramid of Giza. Not the brown, crumbling structure surrounded by sand and tourists that Ash had seen her whole life on TV.  The structure was covered in white limestone sheeting and gleamed in the sun.  The top was painted and inlaid with gold and silver. Temples, obelisks, and statues crowded around the base.

    Alim said, “It is hard to find words, is it not?”

    All Ash could say was, “Yes.”

    The ship made its way up the Nile, and the two smaller pyramids came into view, initially blocked by the great pyramid. Ash said in English, “I can not believe I am on a Phoenician trader, rowing into the harbor at Giza, and the pyramids are there, right in front of me.”

    Being a person from the 21st century, her impulse was to pull out her phone, take a picture, and post it on social media. With a physical jump, she remembered the project she had been working on before the pirate attack.

    Ash turned to Alim, grabbed him by the shoulders, and shouted in his face, “Alim, the lightning jar! Was it damaged in the attack?”

    – To Be Continued –

    Please subscribe to our newsletter, so you will know when the next installment, “Temple of Spies,” is released, wherein Ash and friends seak information and allies in Giza, but find danger as well.

    Ancient Egypt: 2,500-year-old shipwreck PROVES Herodotus' Nile cargo boat  DID exist | World | News | Express.co.uk

  • Friday Flownex Tech Tips #5

    Custom Result Layers!

    The result layers in Flownex have evolved quite a bit over the last few iterations of the code. Although we might typically associate color-gradient results more with 3D CFD, it does have a place in 1D system modeling. Taking advantage of results layers in Flownex can give a very quick understanding of what is going on with our system, and, with a little customization, can be incredibly powerful as an addition to our design and analysis toolbelt. In this post I am using Flownex version 8.12.7.4334.

    How to create a result layer

    To create a custom result layer we must navigate to the results ribbon and select result layer setup.

    First we want to right-click in the Result Layers window and add a new result layer.

    There are two options to add the schema for our result layer. The first is to right-click on the Selected Result Layer Schemas and add either a specific or generic schema. The second, and my PREFERRED, method is to simply drag and drop results from components on the canvas into this window:

    Note that I want to multi-select any component types which will be included in this result layer. This could be any flow components which share a common result such as “quality”. I also convert to generic because I want the result layer to apply to all pipes, not just the pipe I initially drag and drop the property from.

    Defining the custom result layer

    In this example I have a two-phase water network with a cold external temperature. I want to create a result layer to quickly see if the water is in the gas phase, liquid phase, or somewhere in-between. The problem I have been tasked with solving is ensuring that the water never condenses. I will need to determine where we may need to add additional heat flux to the network.

    We can use the Quality result property to determine the phase of our fluid. Quality < 0 indicates fully liquid, quality between 0 and 1 indicates liquid/gas mixture, greater than 1 indicates fully vapor.

    To make this work as intended I can set up a gradient with three increments going from -1 to 2. The idea being the lowest increment would encompass -1 to 0, middle increment would be 0 to 1, and the top increment would be 1 to 2. For the gradient mode I made sure to pick so that the max and min increments would extend past the specified range.

    As we apply this to our network we can easily see that we do, in fact, have a phase change from gas at the inlet, to mixture in the second two component, to fully liquid near the outlet.

    I may decide to add a heater to our outlet pipe and perhaps a thicker insulative layer to all three to attempt to keep the water in gas phase throughout the system.

    Bonus Tip!

    • Result layers can also be super handy when troubleshooting to quickly identify large pressure differentials, choking points, or other outlying fluid properties.
  • Materials, Composites & Scripting Updates in Ansys Mechanical 2021 R1 – Webinar

    Composites provide new solutions for manufacturers looking for stronger, lighter and more cost-effective materials.

    At the same time, they pose new modeling and manufacturing challenges because of the nature of the materials. With the right simulation tools, designers can account for residual stresses, predict performance, analyze reliability and potential failures, optimize construction, and export accurate information to manufacturing, all before a physical prototype is built.

    Join PADT’s Application/Support Engineer and materials Expert Doug Oatis to learn more about updates made to the composites, materials and scripting capabilities in Ansys 2021 R1.

    Register Here

  • All Things Ansys 089: Design for Autonomous Robotics

     

    Published on: June 1st, 2021
    With: Eric Miller & Jonathan Byars
    Description:  

    In this episode your host and Co-Founder of PADT, Eric Miller is joined by Jonathan Byars of AMP Robotics to discuss their recent presentation at Ansys Simulation World 2021, covering how Ansys mechanical aids in the design of quick release gripper mechanisms for autonomous material recycling robots.

    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!

    Listen:
    Subscribe:

    @ANSYS #ANSYS

  • Flownex Friday Tech Tips #4

    How to make a great compound component!

    Compound components make it easy and efficient to reuse the same collection of components over and over throughout your models. In this post I’ll be going over the basics of making a user-friendly and aesthetically pleasing compound component. In this example I am working in Flownex Version 8.12.7.4334

    How to create a compound component

    To create a compound component we must first create a local library in the project database. This can be done by right-clicking on the project database in the components pane and select “New Library”.

    We can name our new library and choose a picture if desired:

    To create our compound component we just need to right-click on the new library and select “New Compound Item”

    To build our compound component we’ll use the “edit” function on the compound component. In this example I am building a Lohm resistor component. It’s a good idea to test my component on a separate page to make sure scripts interact as expected and validate results against some given test cases.

    Let’s make it functional!

    To define the inputs and results we’d like to expose to the user we right-click on the new compound component in the library and select “component setup”.

    To add inputs and results we need to navigate to the Compound Setup ribbon and then simply drag and drop inputs and results into the Selected Properties window. Note that we can even grab whole categories of inputs or results to save time!

    Now those inputs and results will appear to the user when they add this compound component to their canvas!

    Let’s make it pretty!

    To make our component more aesthetically appealing let’s replace the boring default icon with one more representative of our Lohm Resistor. To do this we right-click on our compound component again and this time stay in the “Display Setup” tab. We can click the “Choose Picture” button to upload our own icon. To refresh on the image selector check out the blog post on adding a background image.

    To correct the aspect ratio so that it shows up looking less squished on our canvas we want to change the settings back in the Compound Setup tab. I’ll change it to 133×34 so that it appears similar in scale to the standard flow components but correct in the aspect ratio.

    Now when we place our compound component onto our canvas it should look great!

    Bonus Tips!

    • In the compound component setup there is a third ribbon called “Tooltips Setup”. This is where we can define what properties show up when we hover our mouse over the component.
    • Don’t forget we can save compound components in a “database” on a server so that they can be accessed by every Flownex user in your organization.

  • Ansys – Software for Electric Machine Design

    The electric propulsion system has drawn more and more attention in the last decade. There has been a lot of development of the electric machines which are used in automotive and aerospace. It is essential for engineers to develop electric machines with high efficiency, high power-density, low noise and cost.

    Therefore, simulation tools are needed to design the electric machines that can meet the requirement. The product launching time can be reduced significantly with the help of the simulation tools. The design process of electric machine involves the area of Electromagnetics, Mechanical, Thermal and Fluids. This makes Ansys the perfect tool for designing electric machines as it is a multi-physics simulation platform. Ansys offers a complete workflow from electromagnetics to thermal and mechanical which provides accurate and robust designs for electric machines.

    To design high performance, more compact and reliable electric machines, design engineers can start with three Ansys tools: RMxprt, Maxwell and Motor-CAD. The capabilities and differences of these three tools will be compared and discussed.

    1. Ansys RMxprt

    Ansys RMxprt is a template-based tool for electromagnetic designs of electric machines. It covers almost all of the conventional radial types of electric machines. Starting from Ansys 2020R2, some axial types have also been included in RMxprt (IM, PMSM, BLDC).

    Fig. 1. Electric machine types in Ansys RMxprt.

    Users only need to input the geometry parameters and materials for the machines. The performance data and curves can be obtained for different load types. Since RMxprt uses analytical approaches, it can generate results very fast. It is also capable of running fast coupling/system simulations with Simplorer/Twin Builder. Ready-to-run Maxwell 2D/3D models can be created directly from RMxprt automatically.

    2. Ansys Maxwell

    Ansys Maxwell is a FEA simulation tool for low-frequency electromagnetic applications. Maxwell can solve static, frequency-domain and time-varying electromagnetic and electric fields. The Maxwell applications can be but not limited to electric machines, transformers, sensors, wireless charging, busbars, biomedical, etc.

    Unlike RMxprt which uses analytical method, Maxwell uses the FEA approach which allows it to do high accuracy field simulations. Engineers can either import the geometry or create their own models in Maxwell. Therefore, there is no limit of types of machines that can be modeled in Maxwell. It can model all types of electromagnetic rotary devices such as multi-rotor and multi-stator designs.

    Fig. 2. Electric machine detailed model in Ansys Maxwell.

    Maxwell can do more detailed electromagnetic simulations for electric machines, for example, the demagnetization of the permanent magnets, end winding simulations and magnetostrictive effects. With Maxwell, engineers are able to run parametric sweep for different design variables and to do optimizations to achieve the optimal design. Maxwell is also capable of creating equivalent circuit extraction (ECE) models. The ECE is one of the reduced order modelling (ROM) techniques, which automatically generates an efficient system-level model. There are several Ansys customization toolkit (ACT) available for Maxwell to quickly create efficiency map and simulate impact of eccentricity. Furthermore, Maxwell can be coupled with Ansys Mechanical/Fluent/Icepak to do thermal and mechanical analysis.

    3. Ansys Motor-CAD

    Ansys Motor-CAD is suitable to make design decisions in early design phase of electric machines. It includes four modules: electromagnetic, thermal, lab and mechanical. Motor-CAD can perform multiphysics simulations of electric machines across the full torque-speed range. Motor-CAD uses a combination of analytical method and FEA, and it can quickly evaluate motor topologies and optimize designs in terms of performance, efficiency and size.

    Motor-CAD is capable of simulating the radial types of electric machines. With its lab module, it can do the duty cycle simulations to analyze electromagnetic, mechanical and thermal performances of electric machines. The thermal module is a standard tool in industry which can provide fast thermal analysis with insight of each thermal node, pressure drop, losses. Motor-CAD mechanical module uses 2D FEA to calculate the stress and deformation. Engineers can also manually correlate the models in Motor-CAD based on the manufacturing impacts or testing data.

    Fig. 3. Ansys Motor-CAD GUI and machine types.

    Motor-CAD can provide links to Ansys Maxwell, Mechanical, Icepak and Fluent for more detailed analysis in the later phases of motor designs.

    • What to use?

    RMxprt and Motor-CAD both can handle most of the radial types of electric machines. RMxprt can also model some conventional axial flux machines. RMxprt can purely model the electromagnetic performance of the machines, while Motor-CAD can simulate electromagnetic, thermal and mechanical performances.

    Maxwell can simulate any types of machines (radial, axial, linear, hybrid, etc.) as it can import or draw any geometry. Both static and transient analysis can be conducted in Maxwell.

    • When to use?

    RMxprt and Motor-CAD are most suitable in the early design stages of the electric machines. Engineers can get fast results about the machine performance and sizing which can be used as a guideline in the later design phase.

    Maxwell can be used in the early design stages for more advanced types of electric machines as well. Maxwell is also capable of doing more detailed electromagnetic designs in the later stage and can be used to do system-level transient-transient co-simulation (coupled with Ansys Simplorer/Twin Builder). More detailed geometries, advanced materials and complex electromagnetic phenomenon can be modeled in Maxwell. In the final stages of running more advanced CFD and NVH analysis, Maxwell can be linked with Ansys Fluent/Icepak/Mechanical to ensure the design robustness of the machines before going into prototyping/production.

    • Who can benefit?

    RMxprt and Motor-CAD do not require strong FEA simulation skills as no boundary conditions or solution domain need to be set. Engineers with basic knowledge of electric machines can get familiar with the tools and get results very quickly.

    Maxwell requires users to setup the mesh, boundary and excitations as it uses the FEA method. Engineers will need to acquire not only the basic concepts of machines but also some FEA simulation skills in order to get more reasonable results.

    Summary

    RMxprt: It is a template-based tool for initial electric machine designs which uses analytical analysis approach.

    Maxwell: It uses FEA approach model both 2D and 3D models. It is capable of simulating either simple or mode advanced electromagnetics in electric machines.

    Motor-CAD: It is suitable for initial machine designs which uses analytical and FEA methods. It can do electromagnetic, thermal and initial mechanical analysis.

    If you would like more information related to this topic or have any questions, please reach out to us at info@padtinc.com.