STAR-CCM+
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In this video we look at the Lagrangian method for multi-phase models. There are two main Lagrangian methods within STAR-CCM+, LMP (Lagrangian Multi-Phase) and DEM (Discreet Element Method).

With the Lagrangian Multi-Phase you're essentially injecting a number of particles into your simulation flow. Usually this is done with sprays and droplets, so there are thousands or millions of particles injected, grouped into what is called parcels and tracked throughout the flow. It has many uses, it can be done for steady state, it can be done for transient analysis. The particles can be part of reacting flow if you're doing combustion, either a liquid fuel or solid fuel, but with LMP models, it will calculate the particle path, and that path will be saved and  you can go back and plot what the particle path was for your analysis.

We also look at a demo example we put together using rubber balls that are turning around and being mixed in a rhythm mixer. This is  using an overset mesh to model the motion of the blades. It could be done with a rigid body motion, but we thought this would be a good application just to demonstrate the use of our overset mesh. One advantage of an overset mesh is if you want to make a modification, let's say using two ribbons that are standing next to each other and a wider bat that might be intermixing with the space, that would require the overset mesh.

We open up the model and go through how it's set up, how the over mesh is defined and poke around how we set up the DEM model itself.
 

In this demo example, we show a simple VAT mixture with a paddle and we spin it up to about 240 RPM. As it spins up, a well develops within the fluid of the model. We're using eurlerian multi-phase in this example between the air and water phases and we're using a volume of fluid to define the sharp interface between the two phases.
 
In our demo we open up this model and investigate the geometry, look at the region definition, show how we can apply motion to this, show how we set up the phases, set up the phase & our actions, and also get some engineering values out of this, such as evaluating what the shaft power requirements are.
 

In this STAR-CCM+ tutorial we take a look at combining motion and multi-phase. With motion, there are three big methods of modeling motion within your simulation study. These aren't the only ones that are available in STAR-CCM+, but these are definitely the most applicable to the a models that we discuss in this video.

The first type of motion that we explore is called the moving reference frame. This is basically a time average technique.

Then we get into discussing a little bit more about rigid body motion. There's lots of similarities to setting up the problem between moving reference frame and rigid body motion, but rigid body motion will give you a time accurate transient solution.

And then probably the most flexible of methods for introducing motion into your simulation is going to be the use of overset mesh. We have examples that we'll look at using the rigid body and overset mesh in this webinar. Some consider overset mesh as the future for CFD.

 

How are mixers, washers and sprayers currently modeled? Are they even modeled? Are regulations, efficiencies, or performance concerns making you want to reevaluate the design process?

In this online seminar, we look at how STAR-CCM+ can be used to meet these challenges. STAR-CCM+ is a premier CFD and Multiphysics modeling tool that can be used for modeling spray, particles flow, motion, films, and non-Newtonian fluids.

This tutorial reviews available toolkits for simulating motion and multiphase flow with a focus application on mixing and wash. We evaluate the different methods for setting up these models and provide work through some tutorials on model setup.


Simcenter STAR CCM Version 2019With STAR CCM+ 2019.2, Siemens PLM introduces new features that advance the visual storytelling component of engineering communication. The new edition introduces photorealistic rendering and a virtual reality environment that lets you immerse into your simulations and models. 2019.2 launches screenplay, enabling the creation of informative and persuasive animations effortlessly. Screenplay uses an intuitive drag and drop interface that allows for quick animation and interpolation of simulation views and visualizations. The animations allow you to bring your simulations to life and better convey the context by adding impact to the way you can communicate results to clients and colleagues.

STAR-CCM+ is unmatched in automation, increasing productivity and enabling design space exploration. The new simulation operations capability takes the automation to a whole new level. You can now build and execute a sequence of simulation actions directly from the interface without macros. With execution intelligence now an integral part of the simulation pipeline and the reduced need to write macros you can seamlessly orchestrate the various execution aspects of a simulation, allowing you to drive complex simulations through to results with just the single click of a button. 2019.2 includes many more features and updates to help increase productivity and accuracy.

DOWNLOAD FULL NEW FEATURES PDF

 

This demo gives a quick run-through demonstration of STAR-CCM+, focusing on the workflow. We’ll be quickly bringing in a 3D model and show how we can use the meshing pipeline within STAR-CCM+ to extract the fluid volume of the part that we're interested in.

After that we go ahead and apply the physics, define boundary conditions and mesh our fluid volume. We'll be able to set up a few post-processing images, assessing data and be able to run the model, evaluate some of the results that we get from the model and also look at ways that we can improve the results that we get, again, by going back into the meshing pipeline that is offered within STAR-CCM+.

 

 

The way we think of the design process is changing. In this online seminar we cover where CFD & engineering design trends are headed, and help you explore STAR-CCM+, the integrated multiphysics solution for CFD engineers.

We start by looking at where CFD is headed, with a focus on the development of the digital twin. Then we dive into two specific examples of design optimization.

Simulation engineers usually spend most of their time in a scenario like this: you've got one person or a team test exploring the design space, you're putting together the models and trying to test and debug them. By the time there’s a solution and the team can actually do some exploration, they’ve got to wrap everything up and move on to the next fire.

But in truth most of your value is going to come from exploring and assessing the design space. That's where you're going to find your optimal design, your optimal solutions to the problem. The team might be missing the designs that would maximize their reduction in heat, or maximize their thermal performance or any other metric that they’re going after.

 

 

By using STAR-CCM+ the same team can discover better designs, faster. The first aspect is the implementation of parametric models. Built into Star CCM+ is its own 3D CAD tool, which is actually a pretty solid 3D CAD tool. There's a lot that can be done with it. A user can also link to exterior CAD tools such as NX or bring in geometry from pretty much any other CAD tool out there as a native or neutral format.

One of the biggest strengths of STAR-CCM+ is a flexible, robust meshing. It was a pioneer in developing polyhedral meshing. This is a superior form of meshing, especially for handling swirling flows to make sure that your flow is perpendicular to the face. It has a surface wrapper too, enabling you to basically bring in nearly any geometry that you have no matter how complex it is.

In this seminar we also show a couple of examples that we've worked on at Predictive Engineering. The first one is a float mixing problem from an old HVAC job that we had some years ago. The unit sits on top of the hospital and it’s the air mix of a return air and new air mixing in before it goes into the heat exchanger racks. The challenge is to avoid getting hot and cold spots inside the system. Usually you have to have very large spaces and you have these blades so they're set up to turn it. But in this case there are some space limitations.

The second example focuses on wind turbine blades and is a multi objective study because we want it to both look at increasing the velocity through the metal and decreasing the overall drag force. We ran through about 120 different design iterations and on the input parameters we set, when it runs into nonsensible geometry, it just throws it out, skips over it, and it goes onto the next one. It doesn't hang up the software. It really reviews the space automatically for you.

We ended up with about a 30% increase in the velocity. So one can see there can be great gains with a higher velocity and also a reduction in the drag force.

Simcenter EngineerInnovation final 1Carrying the torch onward from CD-Adapco, Siemens has introduced a new publication focused on simulation analysis. Fittingly the first cover of Engineer INNOVATION celebrates some of the many faces of physics, science, mathematics, and innovation that have influenced our lives and the work we do.

Articles of interest to our community include:

  • Project Tailless Drone - CFD simulation and wind tunnel test correlation for a tailless multi-variant sUAS
  • Thales Alenia Space - Exploring new tools and methods for acoustic testing in the space industry
  • Fresh Air on the High Seas - Predicting exhaust plume dispersion on cruise ships

Click here to download the new issue

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