MMP Software

ANSYS 13

ANSYS 13.0 includes a great number of new and advanced features that make it easier, faster and cheaper for customers to bring new products to market, with a high degree of confidence in the ultimate results they will achieve. The product suite delivers new benefits in three major areas:

• Greater accuracy and fidelity: As engineering requirements and design complexity increase, simulation software must produce more accurate results that reflect changing operating conditions over time.
• Higher productivity: ANSYS 13.0 includes dozens of features that minimize the time and effort product development teams invest in simulation.
• More computational power:  For some engineering simulations, ANSYS 13.0 can provide speedup ratios that are five to 10 times greater than previous software releases. Even complex multiphysics simulations can be accomplished more quickly and efficiently, speeding up product development and market launch initiatives.

ANSYS 13.0 builds on the foundation of previous ANSYS releases, taking product development to the next level by continuing the evolution of Smart Engineering Simulation. By compressing design cycles, optimizing product performance across multiple physics, maximizing the accuracy of virtual prototypes, and automating the simulation process, ANSYS is making it easier and faster than ever to bring innovative new products to market — which has become imperative in today’s difficult economy.

ANSYS Workbench Framework

Improved Evaluation of Multiple Design Points
Building on the strength of ANSYS Workbench parametric simulation, the efficiency of design point updates has been improved. First, when updating a design point, only those systems and components required to bring all output parameters up to date are calculated. Adding systems or making changes that do not affect those output parameters will not cause design points to go out of date.

When complex projects involving multiple physics are calculated, output parameters are shown as they are calculated. This improves feedback and provides more information in cases where a design point is only partially up-to-date.

A new option has been added to update design points in order, which can avoid unnecessary regeneration of the mesh when subsequent design points use the same geometric configuration.

ANSYS DesignXplorer Accuracy
When performing sensitivity analyses or optimization based on response surface techniques, the user needs to determine the accuracy of the response surface and, therefore, the trustworthiness of the approximation. A good approximation is required to extract meaningful results from sensitivity studies. Several new features in ANSYS DesignXplorer software reinforce the accuracy of the results.

New design of experiment (DOE) schemes are now available. Sparse grid, for example, is a dynamic DOE response type that features automatic adaptive refinement. This capability adds design points based on response surface gradients until the relative error drops below a certain threshold.

Accuracy can be checked visually by using these sampling points (from the design of experiments) in combination with additional verification points. These points are plotted against the estimated response surface. Points close to the diagonal are more accurate when compared with the response surface.

Microsoft Excel Interoperability
Microsoft® Excel® is one of the most widely applied tools for engineering. With ANSYS 13.0, the ANSYS Workbench platform can interact directly with Microsoft Excel spreadsheets.

For parametric analysis with the ANSYS DesignXplorer tool, it is possible to import a table of parametric configurations from Microsoft Excel into ANSYS Workbench for subsequent execution of DOE studies.

In addition, an Excel component system is available within ANSYS Workbench that can enable Excel to exchange parameters with the ANSYS Workbench project. Parameters can easily be flagged in Excel using the "name a range" method and values from those cells are then exchanged as ANSYS Workbench input or output parameters. In this way, optimization can be conducted based on Excel-calculated parameters, such as cost. In addition, the Excel system can introduce a reduced-order model (ROM) coupled with parameters from other systems in the project schematic.

Extending the Reach of the Remote Solve Manager (RSM)
The Remote Solve Manager (RSM) is a tool for job queuing and remote job submission that has been in use for several releases with the ANSYS Mechanical application. At ANSYS 13.0, it has been extended for use with other solvers, so that the most computationally intensive simulation task, the solver update, can be queued to wait for available computing resources, potentially on remote machines. This capability has also been made available for the update of design points. By getting the computational heavy lifting off the desktop workstation, engineering productivity can be greatly enhanced.

Meshing

CutCell Meshing
CutCell meshing is a general-purpose meshing technique that produces almost all hexahedral elements on complex 3-D geometry automatically. This meshing algorithm is suitable for a large range of applications, is useful for meshing fluid bodies in both single and multibody parts, and is very easy to set up.

Virtual Split Edge
While automated meshing is important for speedy solutions, engineers require advanced meshing controls to allow interaction with the model. Using both automated and manual meshing techniques can maximize productivity.

The new virtual split edge feature, part of the virtual topology tool for the simulation application, allows splitting of one edge into two virtual edges. The user can define the location of the split either by picking the location in the geometry window or by specifying a numerical value in the details view. This new feature brings several new capabilities:

• Producing a more uniform or more controlled mesh through manual manipulation
• Defining vertices to apply loads and boundary conditions when they are not present in the geometry

Fluid Dynamics

Turbulence Models
ANSYS 13.0 contains many new and improved turbulence models that allow physical phenomena to be captured more accurately.

• An embedded large eddy simulation (LES) option allows computation of an LES solution in part of the flow domain while a RANS model is used to model the rest of the domain. While LES is more time consuming because of the complexity of the phenomena, RANS runs much faster. Combining both models to enforce LES only in the areas of interest allows speedup of the computation while maintaining accuracy.
• A key addition for turbulence modeling in ANSYS CFX software is the bounded central difference (BCD) discretization scheme to avoid unphysical wiggles (solution oscillations) that could appear in scale-resolving simulations such as LES/DES/SAS.
• Access to the k-omega model for multiphase cases has been added to ANSYS FLUENT software. This capability extends support to the full range of two-equation turbulence models in this product.
• ANSYS FLUENT now contains the scale-adapted simulation (SAS) turbulence model, which is an unsteady RANS approach for accurately modeling separated flows quickly without using LES.

Mesh Swapping and Remeshing
New capabilities have been introduced to increase accuracy using better mesh quality.

• Key-frame mesh swapping allows a discrete change in the mesh during the solution based on a sequence of pregenerated meshes. At each mesh swap, the current solution is interpolated onto the new mesh. Meshes to be swapped must have the same region topology. The mesh can be smoothed between swaps. Dynamic mesh events can be used to define the time and file name for each mesh swap during a simulation. The key-frame mesh swapping approach complements ANSYS FLUENT software's built-in remeshing options for transient moving and deforming mesh cases.
• A Cartesian remeshing capability added in ANSYS 13.0 increases accuracy. Cartesian remeshing is available for remeshing entire regions (that do not have conformal connections to adjacent regions) during simulations using a new option for the dynamic mesh model. Manual Cartesian remeshing of entire regions is available to allow easy switching from tetrahedral meshes to Cartesian meshing technology without having to return to the pre-processor.

Multiphase Flow
Additional multiphase capabilities have been added to ANSYS 13.0 to address more applications with greater reliably and accuracy as well as to meet users' evolving CFD needs.

• A new Eulerian nucleate boiling model allows simulation of subcooled boiling at walls, including nonequilibrium subcooled boiling and superheated vapor.
• The suite incorporates the full release of the compressive discretization scheme (which was beta at ANSYS 12.0). This new scheme is faster and generates results similar to the standard VOF formulation for time-accurate transient analysis.
• For Lagrangian multiphase, a packing limit option has been added to the dense discrete phase model (DDPM) to prevent unlimited accumulation of particles. This option allows simulation of suspensions and flows such as bubbling fluidized bed reactors operating at the packing limit conditions. It also allows for polydispersed particle systems.
• The Kelvin–Helmholtz; Rayleigh–Taylor (KHRT) breakup model is an addition to ANSYS FLUENT software's suite of spray breakup models. KHRT is an advanced model for simulating primary and secondary droplet breakup at high Weber numbers.
• The new coupled level-set method is an alternative to the VOF model for interface tracking. It offers some improvements in computing gradients and curvature as well as a better prediction of surface tension force.

Solid Motion and Temperatures
Various capabilities have been added to ANSYS 13.0 that address reliability and accuracy.

• In ANSYS FLUENT software, the independent specification of reference frame and moving mesh in cell zones allows specification of the movement of a moving reference frame (MRF) independent of the movement of the mesh for the same zone (enabling inclusion of both multiple reference frames and moving mesh methods in the same zone). The multiple MRF zones can be defined within a case, including MRF zones embedded in another MRF zone, so that motion induced by multiple MRF zones can be modeled. Examples of combined motion that can now be simulated are oscillating fans and a car turning a corner with the wheels rotating.
• In ANSYS CFX technology, porous CHT objects can now be modeled with separate fluid and solid temperatures. A user can specify the interfacial area density between solid and fluid together with a heat transfer coefficient. Energy is then conducted through the solid based on the solid properties and exchanged with the fluid.

Design Optimization
Parametric studies help companies design better products or obtain an in-depth understanding of product behavior. Automatic shape flow optimization for fluid dynamics analysis uses gradient information, mesh-morphing technology and an optimizer that are all integrated into the ANSYS FLUENT solver. In one case study, the design criterion was to automatically determine channel shape for which the outflow velocity would be most uniform. The original design incorporated straight sides, and the resulting outflow was nonuniform. The ANSYS FLUENT automatic shape flow feature then determined that a curved shape provided a more uniform outlet velocity profile.

Structural Mechanics

Beam and Shell
A number of new capabilities enhance structural analysis.

• Specifying variable thickness on surface bodies: The thickness of selected faces on a surface body can be specified. Variable thickness can be specified through tabular or function input.
• Enhanced edge visualization: Options improve the ability to distinguish the edge connectivity in a surface body by inspecting geometry and meshes.
• Mesh connection: This feature allows manual or automatic joining of meshes for neighboring surface bodies that may not share topology in a multibody part.
• Line body end releases: Edge interactions on line bodies can now have degrees of freedom released between a vertex and an associated edge.
• Shear-moment diagrams: Diagrams are available for simultaneously illustrating line body results as the distribution of shear forces, bending moments and displacements.

Restart for Nonlinear Simulation
The ANSYS Workbench platform delivers solutions that provide ease of use and productivity even for complex nonlinear simulations. ANSYS 13.0 introduces the ability to perform restarts on nonlinear simulations.

For example, if the solver stops because of convergence issues or the user needs to check intermediate results, the entire solution no longer needs to be recomputed from beginning to end.

Restart analysis and restart controls are included in the analysis settings for static structural and transient structural analyses. This capability allows the analysis to be restarted under a variety of conditions, such as time step changes. These restart points can be managed in the timeline and tabular data windows. Jobs can be interrupted and restarted for local, RSM and distributed solutions.

Cyclic Symmetry Analysis
Many companies in the turbine industry require cyclic symmetry analysis functionality. For many years, ANSYS structural solutions have allowed patterned geometries (also called cyclic symmetry models) to be computed using only a sector of the model. ANSYS 13.0 now exposes the capability in the ANSYS Mechanical environment.

Nonlinear Simulation
Most engineering simulation applications require nonlinearities of some kind, such as contact or materials. The ANSYS focus on nonlinear capabilities delivers easy-to-use, advanced and robust tools so these simulations can be performed as easily as linear analyses.

With ANSYS 13.0, a prestressed modal basis at any load step of a linear or nonlinear model can be computed. In previous releases, only linear states were considered for computation of the modal basis (eigenvectors and frequencies).

Release 13.0's underlying technique is called linear perturbation, which has been developed in the core solver and is available to ANSYS Workbench users. The technique radically differs from the method (based on PSOLVE and other APDL commands) previously used to compute nonlinear prestressed modal analyses.

In setting up the nonlinear and prestressed modal analysis, the user process is the same except the choice of the time step.

Tightly Coupled FSI
To accurately model the interaction between fluids and solids, it is best to use two different solution methods that are tightly coupled and directly communicate as the simulation progresses. Fluids and gases are best handled with a method called Euler, while structures are handled by the Lagrange method. The interaction between the two parts is called Euler–Lagrange coupling, or fluid–structure interaction (FSI). The coupled method handles boundary interactions between the two parts of the same problem.

FSI is now available to users of the ANSYS Explicit Dynamics solver with one mouse click. When the user indicates that the fluid part of the problem's reference frame is Euler, the virtual Euler domain is automatically created. For users of ANSYS Mechanical within the ANSYS Workbench environment, the model definition is very similar to an implicit simulation, making it is easy to learn and use.

Variational Technology
Variational technology (VT), an innovative way to compute simulation results faster, has been extended in ANSYS 13.0 to frequency sweeps and the computation of modes in the case of cyclic symmetry problems.

Typical speedup ratios found with such problems range from five to 10. Higher ratios can be achieved when there are more steps in the frequency range or more indexes required for the cyclic symmetry.

Variational technology also can be used for thermal transient runs and parametric variations. This capability was introduced in earlier releases.

3-D Rezoning
This unique feature is provided within ANSYS structural mechanics solutions for materials that exhibit extreme shape deformation, such as plastic, rubber and foam.

Traditionally it has been difficult to arrive at an accurate solution. When very large deformations are encountered, the low quality of the distorted mesh might prevent obtaining a solution over the entire time range. In that case, the simulation needs to be stopped, the volume remeshed in its current state, and the simulation continued after all quantities have been remapped, including contacts, material property assignment, loads and boundary conditions.

The new 3-D rezoning solution mapper technology automatically handles contact and boundary conditions mapping from the old mesh to a new mesh. This solves the model to the limit of confident accuracy.

Rigid Body Dynamics 3-D Generalized Contact
Fully rigid simulations (in which no stresses or strains are computed) provide a quick and efficient way to determine forces and relative motions of a mechanism. However, a mixed rigid–flexible approach is needed to determine how stresses evolve in some members of a mechanism — a capability useful for predicting life estimates.

The ANSYS Workbench platform provides unparalleled ease of use when setting up a rigid–flexible model. The user simply indicates which bodies are considered as flexible and which ones are considered as rigid. The Rigid Body Dynamics module from ANSYS is used for computing mechanisms and the interaction between bodies. In many mechanisms, the probability for the motion of some parts to be contact driven is very high. One example is a cam-driven mechanism.

With ANSYS 13.0, the Rigid Body Dynamics add-on supports 3-D generalized contact. Contact detection is performed automatically, as with any other structural analysis, and the solver ensures proper detection of the impacts.

Kinematics capabilities — which include configure and redundancy tools to determine if a model is set up properly by dynamically checking joints and to examine redundancies, respectively — are now available in most ANSYS structural mechanics solutions.

Design Assessment System
A new analysis system called design assessment is available with ANSYS structural mechanics products to allow management of load combinations and customized post-processing (such as code checks) based on ANSYS programs or the users' own programs.

The design assessment system enables the selection and combination of upstream results along with an optional ability to further assess results with customizable scripts. It allows the user to associate attributes, which may be linked by geometry but are not necessarily a property of the geometry, to the analysis via customizable items that can be added in the tree. Custom results can be defined from a script and presented in the design assessment system to enable complete integration of a post-finite element analysis process. The scripting language supported is python-based. Script location and available properties for the additional attributes and results can be defined via an XML file, which can be created easily in any text editor and then selected by right-clicking on the system's setup cell.

A user can add this release 13.0 feature to a static structural or transient structural analysis. Predefined scripts are supplied to interface with the ANSYS BEAMCHECK and ANSYS FATJACK products.

HPC with GPUs
Committed to providing the most advanced and modern high-performance solutions, ANSYS monitors the evolution of hardware to leverage its power for customers. The overarching goal is to reduce time to solution.

ANSYS 13.0 leverages the power of graphics processing units (GPUs) to offload heavy number-crunching algorithms onto more powerful GPU cards, which are capable of performing general-purpose computations using double-precision accuracy. This capability is available for the ANSYS Mechanical and Nexxim solvers.

Electromagnetics

HFSS Transient Solver
This solver, based on the discontinuous Galerkin time domain (DGTD) method, uses an unstructured, geometry-conforming mesh to accurately simulate complex geometries. Computer memory usage is modest because the underlying method doesn't require the solution of a large matrix equation. It has an innovative local time stepping procedure that optimizes runtime, stability and efficiency.

The HFSS transient solver can handle complicated and curved geometries because of the flexibility of the unstructured meshes used in DGTD. The new method provides powerful significant advantages over simulation by conventional brick-shaped FDTD and FIT meshers.

Hybrid Equation Solver
ANSYS 13.0 introduces the first commercial code that performs a hybrid solution between finite element methods (FEM) and integral equation (IE) methods for high-frequency electromagnetics problems. In the FEM method, the FEM volume must be truncated into an outer surface. This traditionally has been a type of absorbing boundary condition (ABC). Though ABC is a good absorber, it is not a perfect absorber. Hybridizing the code provides a perfect absorber and highly accurate fields. The IE surface can be placed very close to the surface and can have convex shape conforming to the structures. This minimizes the volume and speeds the solution.

HSPICE Integration
Ansoft Designer software has been linked to the popular circuit simulator from Synopsys, HSPICE. This configuration provides a powerful user interface and direct links to electromagnetics software such as HFSS and SIwave. As a result, users can now quickly and accurately analyze signal-integrity, power-integrity and electromagnetic interference (EMI) problems from a single schematic- and layout-based environment.

Multiphysics

External Data Mapper
ANSYS continues to align Simulation Driven Product Development with real-world business challenges. At many organizations, engineers from different disciplines work on a single design, often using different tools. Those working independently on CFD often need to exchange data with those working on structural analyses — for example, when CFD pressures are applied to a structural model.

With ANSYS 13.0, the new external data mapper imports external data in the form of a text file defining a point cloud and the data to be projected onto the current mesh. The external data mapper allows users from different groups (such as CFD and structural) to exchange model data in a straightforward manner. It also provides the capability to import data from third-party applications. Body temperatures, surface pressures and heat transfer coefficient can be easily mapped from a data source onto a new simulation. The user can define the units for the data to be imported and align the imported data using current geometry. Visual controls identify how the point cloud data is aligned with the model. Data mapping works from 3-D data to 3-D geometry as well as from 2-D data to 3-D geometry.

Electromagnetic–Structural Coupling
This feature has been enhanced through tight ANSYS Workbench project schematic integration between the Maxwell and ANSYS Mechanical solvers. Maxwell passes electromagnetic force densities to the ANSYS Mechanical solver within the ANSYS Workbench environment. Forces are mapped automatically across a dissimilar mesh interface to the structural model, and the structural solution is performed including the electromagnetic force densities. This new capability allows users to calculate mechanical deformations and stresses for a wide range of electromechanical applications, including electric motors, transformers and superconducting magnets. The entire coupled solution is parametric, which allows for fast and easy evaluation of many designs.

Electromagnetic–Thermal Coupling
Electromagnetic–thermal coupling has been enhanced through tight ANSYS Workbench project schematic integration between the HFSS and ANSYS Mechanical solvers. HFSS passes electromagnetic losses to the ANSYS Mechanical solver. Both surface and volumetric losses are mapped automatically across a dissimilar mesh interface to the mechanical mesh, and the thermal is performed including the electromagnetic losses. This new capability allows users to calculate the thermal response for a wide range of RF and microwave components. The entire solution is parametric, which allows for fast and easy evaluation of many designs.

Data and Process Management

Workflows or simulation processes are sequential tasks connected with actions that lead to successful completion of the simulation. The tasks could be assigned to simulation expert staff or machine resources, such as compute clusters.

ANSYS Engineering Knowledge Manager (ANSYS EKM) software handles such CAE-focused collaborative workflows very effectively. New to ANSYS 13.0, ANSYS EKM Studio software defines such workflows, and the process player in ANSYS EKM allows execution of the workflow in a user-friendly way. It captures the process-related information, inputs and decisions automatically. This is useful for audit purposes.