FloEFD Thermal Simulation for LED and Lighting
FloEFD’s LED Module offers a unique range of capabilities required for various lighting applications:
- Its Monte Carlo radiation model is best suited for thermal radiation predictions in lighting applications where lenses or reflectors can cause hot spots in focal points from the light source (solar or man-made).
- A new band-less Monte Carlo model for lighting and radiation allows users to dramatically decrease the time required for defining wave-length dependent properties while increasing the simulation accuracy of spectral characteristics.
- Its new water film model enables simulation of surface condensation, evaporation, icing and de-icing exploration such as condensation on the inner surfaces of automobile headlights.
- Combined thermal and photometric model for LEDs based on T3Ster measurements of actual off-the-shelf LEDs can yield correct power and temperature predictions and “hot lumen” output.
- Definition of radiation spectrum and setting intensity of radiation can now be dependent on the angle. With that data defined, FloEFD now automatically applies the calculated radiant flux on top of the LED.
- Easy ray visualization helps to find sources for radiation hot spots on other parts of the luminaire.
- A water absorption model enables the simulation of absorption of water into the plastic housing of the luminaire and later releases it under the right environmental conditions.
Thermal simulation simplifies LED luminaire development
Every form of electric lighting produces an unwanted by-product: heat. In the case of incandescent and fluorescent lighting, generations of engineers have developed ways to minimize and/ or divert heat from luminaires and fixtures. But LED lighting, appearing today in growing quantity and variations, poses new and different challenges. The
movement to LED lighting systems worldwide is accelerating as energy savings and the reduction in hazardous materials increase in importance.
Validating the design concept
When developing a new luminaire “system,” the basic product concept must be validated, reconciling mechanical and aesthetic ideals with the realities of thermal behavior. The key to successful LED system design is to transfer the active device’s heat efficiently from its own PN junction to the ambient. The path involves both the printed circuit board that mounts the LED and the enclosure. The designer must confirm that housings and shrouds participate efficiently in carrying heat away from the LED. Building and testing a series of physical prototypes to validate this premise is costly and time-consuming, so today’s designers generally use software-based methods in this early design phase.
The preferred approach is to use computational fluid dynamics (CFD) analysis to simulate the proposed device in virtual form.
A full-featured frontloaded CFD application such as Simcenter FLOEFDTM software:
The frontloading CFD flow simulation/analysis step as performed by Simcenter FLOEFD is indispensable for refining design proposals. It is far less costly than building- ing and testing a succession of physical prototypes, and the automation built into frontloading CFD means that preparation for the first evaluation cycle is brief and for every subsequent attempt, even faster. It is an environment that encourages experimentation until the design is truly optimized.
- Uses the dimensions and physical characteristics of the proposed design stored within the MCAD application by directly using the MCAD geometry.
- Detects and grids the solids and flow spaces, creating an optimized computing mesh
- Aids the designer in setting boundary conditions
- Automatically provides solution-control settings to help ensure convergence when the solver runs