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Multiphysical simulation of lighting (now not just automotive)

Lighting systems perform a number of important functions, from road lighting to signaling to improving the visibility of other drivers on the road. It must remain in operation under different environmental conditions. Temperatures can exceed 45 or fall below -20 ° C. In addition, lighting systems must be able to withstand structural loads caused by various external influences. What are the main challenges of lighting simulation?

• Complex and interacting thermal and structural physics with flow physics.
• Exchange of thermal radiation between all components.
• Solar heating.
• Material requirements: temperature, strength, deformation.
• Humidity and condensation: Goretex.
• LED lighting: PCB design and temperature control. Designers and manufacturers are facing increasing challenges as lighting systems evolve and become more complex. Furthermore, they are obliged to adapt their systems to more compact spaces. Temperature management is therefore becoming essential - the aim is to prevent the internal temperature safety thresholds from being exceeded. For example, we either rely on natural convection to dissipate heat, or we need to add a fan to improve air circulation and help dissipate heat.
So how to look at the issue from a simulation point of view? The whole model includes a number of boundary conditions and constraints. These can be divided into three separate categories: structural, thermal and CFD (flow).
 
Structural
• Fixed boundary conditions
• Contacts
• Gravity

Thermal
• Thermal load
• Thermal contacts
• Convection into the environment
• Radiation
• Solar heating

Flow
• Flow surface
• Humidity
• Condensation / evaporation
• Gravity

On the thermal side, we define the thermal load and thermal bonds between identical surfaces. Convection into the environment is modeled as a thermal boundary condition. Where appropriate, radiation chambers are defined. The effect of solar heating may also be included.

On the flow side, it is necessary to define a flow area that allows the transfer pressures to be transferred to the structural solution. Humidity, condensation and evaporation can be added to the CFD model. Finally, it is necessary to define a gravitational vector in order to be able to correctly model natural convection.
   
Last but not least, we always address the question of how we can incorporate this model into more sophisticated workflows. As lighting systems shrink and respond faster, the electronic systems that accompany them also become more complex. Exchange PCBs are a communication set of tools for working with ECAD users. Eliminates time-consuming manual work and related modeling errors and allows for much faster iterative design times. Users usually report a 10x - 30x reduction in the time required to perform their work.
   
Perhaps the most important component in the design of new structures today is the question of how to quickly design the optimal structure. As a product goes through various iterations, designers and engineers often face the question of which design is the best of all. Today's optimizers (like HEEDS) automatically search for and find a set of optimal solutions.
 

 
What software do we most often use for this issue?

Simcenter 3D
FloEFD (in combination with NX, Creo, Catia or Solid Edge)