The last CD-Adapco release of STAR-CCM+ in the 2014 year has been announced. The latest version of the multidisciplinary simulation CAE platform is focusing on improving accuracy, realism, and throughout.
Jean-Claude Ercolanelli, Sr. VP at CD-Adapco said, “We want our customers to have confidence and certainty in their simulations. This is fundamentally based on how close we can simulate the real performance of the final product and produce accurate results … This continued focus on realism and accuracy has allowed customers to break new ground in critical simulation work.”
Accuracy of the Acoustic Waves Solver & MUSCL Scheme
Joel Davison, STAR-CCM+ Product Manager, explained that the acoustic wave solver will improve the accuracy of acoustic simulations by reducing spurious sources of noise created by transitions and numerical issues in the mesh. By separating of the acoustic signal from the flow field, the solver will capture more accurate results. The solver also promises short turnaround for far field acoustic simulations.
Another improvement aimed at improving accuracy is the MUSCL scheme. “The third order MUSCL scheme is a new correction scheme in STAR-CCM+. This will apply to external aerodynamics, aero-acoustics, and large-eddy simulation,” mentioned Davison.
The Scheme minimizes numerical dissipation for higher order convection schemes. This will allow for clearer representation of shockwaves, wakes, and vortices without refining the mesh. After all, who wants to show a blurry vortex contour picture to Mercedes’ engineering marketing team?
Realism of Partial Wrapping and Overset Meshing
For instance in the automotive industry the body of the car will be a clean surface. However, the underbelly will have a lot of overlap and gaps. The partial wrapper will allow you to wrap the underside of the car without compromising the fidelity of the aerodynamic surfaces. This will ensure a faster and easier method than wrapping the whole surface or each parts together.
To improve the realism of simulated interaction between large objects with small elements, CD-Adapco combined the overset mesh and DEM (Discrete Element Modeling) tools. This allows analysts to model more complex motions of large objects which will impact the movement of particles, or vice versa. Obvious applications include digging, drilling, oil & gas, pharmaceutical, and production line industries.
“Also on the overset theme we have the ability to handle gap closure. The overset mesh allows for the movement of objects in CFD simulations easier than traditional mesh morphing. In version 9.06 we have the ability for overset mesh boundaries to contact each other. Something important for gears, valves, pistons, and positive displacement pumps,” added Davison.
PISO Solver and Morpher Throughput Improvements
“For certain cases we find the time step, typically determined by flow characteristics, is constrained by external factors. This includes simulations like engine powertrains where STAR-CCM+ is co-simulating with a 1D code. This will need a small time step to accurately model physics. We see PISO solvers are faster in these types of simulations,” said Davison.
“The mesh morpher has also been improved in version 9.06 to improve throughput. CD-adapco has reduced turn around by improving the usability of the morpher. Essentially, users can preformed free form deformation of the volume mesh to change the design. You can create and visualize gradients and displacements and use them to drag, pull and morph the mesh,” mentioned Davison.
The mesh morpher will be very useful with conjunction of the adjoint solver. The adjoint solver helps designers to understand how shape change can affect the results. These morpher control points can be used in conjunction with the adjoint solver to determine the areas on the geometry with the greatest impact.
“These final new features allow us to deliver on the goal of STAR-CCM+ v9 series that has been focused on accurately simulating large and sophisticated models more easily, faster and in the shortest amount of time … We are setting the stage for our next level of development in versions 10.0x which are due out in February, June and October 2015,” said Ercolanelli.
Other version 9.06 improvements that can help improve accuracy, realism, and throughput include:
- Non-Newtonian Turbulence models
- Vector visualization on nodes
- Importing RCAS, DYMORE, or CAMRAD beam data
- Improved plotting & legends
- 2D meshing
- Harmonic balancing post
- Field Function Preview
Images courtesy of CD-Adapco.