At LEAP we have observed that innovative companies and advanced researchers are moving beyond single physics analysis. There are several reasons why they need to consider coupling multiple physics in their simulations. Firstly, the real-world inherently couples all physical behavior. For example, thermal gradients give rise to material deformation, applied stresses produce electric potentials, fluid flow transports heat and so on. A second reason analysts consider multiphysics is when the intended behavior of their system directly depends on the coupling of physics. For example, MEMs and transducers often derive their mechanical behavior from an electromagnetic input. Next, you may need to consider a multiphysics simulation if further design optimization (required to remain competitive in the market) yields a smaller margin of error and casts doubt on originally assumed uncoupled physics. Or, perhaps physical testing is not possible or practical, and you need to have the highest-level of confidence in your virtual model.
When looking for a multiphysics solution, customers should ask if the vendor would ever be selected for a single physics solution. Customers should also consider if the vendor can offer all the potential physics that they may need. Finally they should consider if the vendor’s technology integrates completely to provide a true multiphysics solution.
The product should include structural, thermal, fluid and both high- and low-frequency electromagnetic analysis. The product should also include solutions for both direct and sequentially coupled physics problems. ANSYS Multiphysics is one such solution.
Examples- Fluid/Structural
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Fluid - Structure Interaction
Tank Sloshing FSI - Transient fluid structure interaction solution including free surface flow, large deformation and isotropic hardening plasticity
Aortic Aneurysm
Two-way fluid structure interaction simulation of Non-Newtonian blood flow in an aortic aneurysm
Graphics Card - a conjugate heat transfer solution calculates temperatures from the fluid flow, the surface temperatures can be sent to a heat transfer model to calculate the solid temperatures and the solid temperatures can be sent to a structural model to calculate thermal stresses
- Piezo/Electric
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Piezoelectic
Piezoelectric Fan - piezoelectric bimorph driven with AC voltage generates the fan blade motion, transient simulation includes large deflection
- Electrical/Thermal/Structural
Electrical - Thermal - Structural CouplingAutomotive Blade Fuse - This example shows one-way coupling between an electric conduction model, a steady-state heat transfer analysis and subsequent thermal-stress calculation for an automotive blade fuse. Joule heating losses were mapped from the electric conduction model and applied as heat generation rates for the thermal analysis, calculated temperatures were then transferred to a structural model to compute thermal-stresses. The Workbench environment controls the load mapping and the workflow for this coupled multiphysics solution as shown in the Workbench project schematic.
Silicon Micro Mirror
Shown here is an example of a reduced order model of a silicon micro mirror. The example demonstrates reduced order of an electrostatically actuated MEMS device with multiple electrodes. The micro mirror cell is part of a complex mirror array used for light deflection applications. Due to the geometrical symmetry, the mirror strips can be divided whereby just one section is necessary for finite element analyses. The results from the analysis show a good correlation with test data.
Solenoid Heating - resistive heating of solenoid actuator. Coil losses were mapped from the magnetostatic model and applied as heat generation rates to a thermal analysis
Silicon Ring Gyroscope – Harmonic response including effects of thermoelastic damping solved with direct coupled-field elements
MEMS Switch - actuation voltage, mechanical contact and fluid damping effects are simulated using electro-mechanical transducer and thin fluid film elements.
