Achieving Fast and Accurate Multiphysics Simulations with GPU Solver Technology

Multiphysics simulations help predict how everyday designs will behave in the real world before engineers actually build them. One key example is conjugate heat transfer, which models how heat moves between a solid object and the fluid (liquid or gas) around it. For instance, if you were designing an engine or electronics enclosure, you would need to capture both the conductive heat flow through the solid objects as well as the convective heat transfer to the surrounding air or coolant, which is highly dependent on the fluid dynamic solution. By simulating the different physics together, engineers can optimize designs for better performance, efficiency, and safety from the very start.

In the past, Multiphysics simulations involved a complex coupling of different tools and solvers, which required specialized expertise and significant computational resources. In today’s world of accelerated design, tools like Ansys Discovery Simulation give engineers a competitive advantage by making relatively complex physics more accessible than ever before. Check out this video to see Discovery Simulation in action.

How do GPU solvers help engineers tackle Multiphysics problems?

In my previous blog, “Why is GPU Computing Good for Simulation Driven Design?” we discussed how Discovery Simulation’s lightning fast GPU solvers unlock the key to simulation driven design: real time results generated at the speed of the design changes. But it’s not enough to just have a fast simulation software. Engineers also need tools that can actually capture the physics of the problems they are working on, and to have confidence that the results are accurate.

Engineers need fast AND ACCURATE  results

Let’s take a look at how Discovery enables fast and accurate results in a real-world example. And since we’re talking about world class GPU solvers, what better example case than a GPU cooling channel?

Starting from a conceptual model of the flow path above, Discovery’s intuitive interface allows users to quickly assign materials and physics. The software autogenerates the appropriate fluid-solid interface behaviors along the flow path and heat sink. Easy Peasy. Throw in a flow inlet, heat generation from the GPU, and a quick exterior convection, and less than 3 minutes later, we’re ready to solve. Oh wait. The model already solved. So on to post processing!

Now if you’ve never done CFD analysis before, you’re probably a bit skeptical that Discovery can give meaningful results with hardly any effort up to this point. And if you HAVE done CFD analysis before, you’re probably REALLY Skeptical. As you should be. 

Looking at a cross section temperature slice of the heat sink, we see that the result is way off! See I KNEW it was too good to be true (pro tip: keep reading to see how the new local refinement features in Discovery address this).

What we’re seeing is a fidelity issue that is common for thin featured geometry. Discovery Explore mode uses a voxel base approach to quickly mesh practically ANY geometry nearly instantaneously. This is great for users who don’t want to spend hours and hours cleaning up geometry or messing with mesh settings. The downside is if features are very small compared to the discretization size, you can end up with solutions that fail to capture the physics important to the problem (in this case, flow/heat dissipation on the thin fins).

Discovery’s user-friendly fidelity slider allows for some improvement, though ultimately the size of your graphics card will dictate how small of a feature that can be captured using the voxel approach. The run of the mill Quadro P3200 card on my laptop is probably due for an upgrade, but it still gets me close to capturing the fins.

Discovery allows easy visualization of voxel resolution, and I can see that even at the highest fidelity, these fins are simply too thin to capture on my machine. Now before you go buy a bigger graphics card, let’s discuss a few of the new fidelity controls that we believe are game changers for the future of Discovery Simulation.

How Can I Improve my Mesh Accuracy with Local Fidelity?

Discovery’s local fidelity option lets you control where to spend your GPU resources to make sure you’re capturing the smallest features in your model. Quickly box selecting the fin geometry and applying a local fidelity yields much better resolution, and I can now visualize the generated mesh.

Another quick solve and I can see that my model is now fully capturing the thin fin geometry.

How do know the results are accurate?

Generating a pretty picture is one thing, but engineers need to know that their simulation data is accurate in order to have confidence in their design decisions. Let’s investigate one more tool within Discovery to see how this plays out.

Discovery Refine Mode

Jumping from super quick explore mode to the more accurate refine mode is a simple toggle in Discovery. In this mode I have more advanced physics options that enable me to specify and preview Polyhedra mesh.

How does Discovery compare to well established CFD solvers such as ANSYS Fluent?

In the absence of test data, we can compare the solver accuracy of Discovery to industry leading codes such as ANSYS Fluent to have confidence that our solution is accurate. Taking a close look at the mesh, we see that we’re able to capture similar levels of boundary layer resolution in each case.

Not surprisingly, the heat profiles generated are nearly identical. This is perhaps especially unsurprising since Discovery is actually using the same exact GPU solver as Ansys Fluent under the hood.

So without leaving the Discovery environment, we were able to generate a result that was within about 2% of the total temperature rise within the first few minutes of effort, and nearly spot on after just a few more clicks. Now that’s the power of Discovery.

Let’s Connect!

Are you still unconvinced that you can have fast and accurate results? Let’s talk! Visit our DRD webpage to get in touch, or join these 2 free webinars to learn more.

Part 1 Webinar: Leveraging Real-Time GPU Solvers for Simulation Driven Designs 

Part 2 Webinar: Empowering Design Engineers with Faster and More Accurate GPU Physics Solvers 

Why is GPU Computing Good for Simulation Driven Design?

Why is GPU Computing Good for Simulation Driven Design?

In my previous blog post, Discovering New Possibilities with Ansys Discovery (and is SpaceClaim going away??), I discussed the geometry modeling capabilities that set Ansys Discovery apart from it’s predecessor, Ansys SpaceClaim. In today’s blog, we’ll discuss the power of CAD embedded GPU solvers in creating better designs faster and more efficiently than ever before.

What is the Difference Between Simulation Validated Design and Simulation Driven Design?

Most companies we work with are familiar with simulation validated design. This approach relies on traditional design methods for initial ideation, and utilizes simulation to verify the design will pass physical testing prior to production or physical prototyping. Without a doubt, this approach saves valuable time and resources over traditional build, test repeat cycles, but is this all simulation has to offer?

Why should you adopt simulation driven design?

Simulation driven design leverages simulation earlier in the product development life cycle, with the following key benefits:

  • Cost and Time Efficiency: By identifying and resolving potential issues early in the design process, it reduces the need for physical prototypes, saving both time and money.
  • Innovation and Flexibility: Enables exploration of a wider range of design alternatives and innovative solutions, fostering creativity and flexibility in the design process.
  • Enhanced Product Performance: Simulation driven design allows for extensive virtual testing and optimization, leading to improved performance and reliability of the final product.

So why are so many companies still operating under a simulation validation paradigm instead of a simulation driven paradigm? I believe the answer to this question lies in the lack of engineering tools available to enable real time simulation feedback as design changes occur. Consider a design change as simple as moving a bolt hole 0.5” to the right. If the designer is required to send an updated CAD model to an analysist, have them rerun the model (if they have time), and wait a week for the results, the data they get back could very well be irrelevant by the time the simulation is complete. This creates a bottleneck that for many companies makes simulation driven design infeasible.

What is a Practical Example of Real-Time Simulation for Design Engineers?

Vent Optimization

Let’s take a look at a practical example to see how the power of real time simulation can be leveraged to guide optimizing a car’s AC system.

Geometry Prep and Simulation Setup

Since Discovery is also geometry editor, it’s super easy to extract the fluid volume and set up the appropriate physics in seconds directly from the 3D CAD.

Assign Air and throw in some inlets and outlets…

Hit solve, and within seconds… 

Not even exaggerating here, you probably could have set up and run this entire model in less time than it took you to read this blog (with minimal training, I might add).

The intuitive and lightning fast setup, meshing, and GPU solver is the real secret sauce for how Discovery gives you real time insights into potential issues as well as understanding how your design changes will impact performance. For instance, it looks like the lower vents are not distributing the flow very well (there is backflow at the feet).


so let’s throw in a vane, update the fluid volume…

And the solver automatically updates the solution in seconds. 

Discovery gives you the flexibility to track output parameters as you design, so you can explore new possibilities faster than ever before. In this case, we see the mass flows are starting to balance, and we’re ready to keep iterating.

Okay. I get it’s fast, but can I trust the results?

I want to end with a few final comments on solution accuracy, since Discovery simulation has come leaps and bounds from its initial debut a few years ago. The latest releases expose some exciting new features that allow you to locally refine your mesh for improved accuracy around small features in Discovery’s Explore mode. Within Refine mode, you can even leverage the same polyhedral meshing and GPU solver technology available in the Ansys’ Flagship CFD Fluent solver, so you no longer have to decide between fast and accurate.

Upcoming Webinars:

Ready to learn more about how Ansys Discovery’s GPU solvers can help you achieve simulation driven designs? Visit our website to learn more details on Ansys Discovery or register for our upcoming 2-part webinar series titled Leveraging Real-Time GPU Solvers for Simulation Driven Designs and Empowering Design Engineers with Faster and More Accurate GPU Physics Solvers.

Discovering New Possibilities With Ansys Discovery (and is SpaceClaim going away??)

If you’ve paid attention to new and emerging technologies in the world of simulation, you may be wondering, “What’s all this hype about Ansys Discovery?” In this blog, we will help answer this question by discussing some of the key features in Discovery, as well as what the future holds for current SpaceClaim users.

Is Discovery Modeling replacing SpaceClaim?

The older SpaceClaim interface has joined DesignModeler as a maintenance mode product in 2023R2. This means the SpaceClaim GUI will continue to be available, and Ansys will continue to perform major bug fixes. However, all new modeling capabilities are being developed within the Ansys Discovery Modeling interface.

How does the new license structure work?

The Discovery Modeling license give you access to all 3 of Ansys’ modeling applications:

  • Discovery Modeling (Simulation comes with Discovery Simulation license)
  • SpaceClaim
  • DesignModeler

Discovery Modeling and SpaceClaim can also be accessed through Enterprise or PrepPost bundles




SpaceClaim and DesignModeler standalone licenses have been discontinued

Benefits of Switching to Discovery Modeling

I already use SpaceClaim, why should I consider learning Discovery Modeling?

If you are a SpaceClaim user, you may be wondering if it is worth your while to switch to something new. Before we dive into new features of the Discovery Modeling package, let’s talk about what this transition actually looks like:

  • With Discovery Modeling license, you can simply open your existing SpaceClaim geometry in Discovery from the workbench page and pick up your projects right where you left off.






If you’re starting a new model from scratch, Discovery continues to support direct import of major external CAD formats.









  • Discovery gives you access to the same features you love from SpaceClaim with a new and improved UI. Ie, Familiar tools with new and improved functionality.

Still intimidated by the new look? Discovery has a plethora of online training materials, as well as tutorials and documentation baked into the application so you can spend less time learning a new interface and more time getting work done. You can also check out DRD’s Discovery learning page for more information.

Ok, Ok, But is Discovery Modeling actually better than SpaceClaim?

So far we’ve covered that Discovery Modeling is highly accessible to existing SpaceClaim users, but is it actually better? We could spend all day discussing the various reasons people are switching to Discovery Modeling, but here are a few of the highlights:

1) Advanced Geometry Cleanup

Clean up models faster in Discovery Modeling with more built in repair and detection features.

2) Advanced Model Prep

Create Beam connections for bolted connections with ease. Model pretension directly in the Discovery GUI, or transfer the connections to Mechanical for higher fidelity solutions.

3) Sub-D

Whether you’re working with 3D scans or geometry generated by Discovery’s topology optimization tool, Designers can say goodbye to STL manipulation headaches with the all new Sub-D modeling. This feature enables interactive organic editing you’ll have to see to believe.

4) Simulation that Just Works

Unlike SpaceClaim, the Discovery GUI goes beyond being just an advanced geometry preprocessing tool by giving designers access to easy-to-use simulation across multiple physics (if Discovery Simulation is licensed). Discovery’s GPU based solvers provide immediate feedback on geometry changes in real time. Need higher fidelity? You can even submit simulations to the flagship Fluent or Mechanical solvers without leaving the Discovery environment.

If you have questions about transitioning from SpaceClaim to Discovery Modeling, one of our experienced staff would love to chat. Contact DRD today to see if Discovery is right for your team!