Powerful, Compact, Electronics Drive Performance
With Power Comes Heat, Stress and Deformation
The calculation of cooling systems like this is impossible with more traditional, analytical methods. Therefore specialists of WayRay’s R&D center aimed to solve this problem using Computational Fluid Dynamics (CFD), based on the finite volume method, using a commercial product from MSC Software, called scSTREAM.
Getting Insight, Impossible from Physical Prototypes
Introducing scSTREAM reduced the number of prototype tests and helped engineers to better understand the physical phenomena by reviewing visual results.
"The CFD analysis from MSC Cradle enables WayRay to shorten the design and prototyping process, allowing engineers to visualize and simulate design variations previously unavailable for physical measurement and evaluation," - (Mr. Maksim Aleksandrov).
The CFD capabilities from MSC Cradle provide a conceptual design and engineering analysis system that has enabled WayRay specialists to rapidly perform parametric design variation studies. By varying the heat dissipation of crystals, material properties, fan speed, radiator sizes and other parameters, it is possible to compare a variety of design options, excluding trial and error, which significantly reduces the time and money spent on preparing and debugging a physical model.
Figures 3–6 shows the results of the thermo-gas dynamics calculations of the laser block of a holographic navigation system developed by WayRay for a Japanese automaker.
The calculated grid, consisting of 24 million elements, was finely tuned in areas of significant temperature change (where laser diode crystals are located). This high-resolution grid is necessary for more exact approximations of the structural elements and the gaps between them.
However, despite the vast number of grid elements, the calculation time in a stationary setting was only 2 hours (for comparison, the duration of a similar calculation with an unstructured grid was 18 hours!). At the same time, the calculation error in comparison with the experimental results was less than 3%.
“CFD has never been so accurate and robust. Thanks to scSTREAM’s high performance, we are now able to quickly create detailed models of over 10 million mesh elements and perform many design verification and optimization iterations per day,” - (Mr. Maksim Aleksandrov).
Based on the simulation results, the heat load and the efficiency of the cooling system were evaluated. The optimal arrangement of fans, Peltier elements, and radiators for temperature distribution and airflows was determined; and stagnant zones and localized heat pockets were eliminated.
The maximum ambient temperature at which the stable function of Peltier elements was assured as was the temperature of the laser diodes, and the overall laser cooling system operation.
The Future with MSC & CFD
In the future the WayRay team plan to incorporate a more complete picture of structural loads, expansion and stresses by exporting temperature variations to strength & structural analysis tools. They also plan to conduct thermal calculations of optical systems as well, given that the MSC Cradle CFD system can take into account lens reflection and refraction due to heat radiation.
"We also plan to conduct thermal calculations of optical systems as well, given that the MSC Cradle CFDsystem can take into account lens reflection and refraction due to heat radiation. Aerodynamic noise analysis is our other challenge," - (Mr. Maksim Aleksandrov).
WayRay chose scSTREAM for thermo-fluid simulation because of its high operability, accuracy and comprehensible GUI. WayRay engineers are satisfied with the capability of scSTREAM and eager to continue to apply the CFD tools to produce excellent computational results and achieve more effective development.