This page contains a Flash digital edition of a book.
FEATURE CAD/SOFTWARE BEAT THE HEAT!


There are different methods of ensuring that a new product does what it’s supposed to, according to Tom Gregory of 6SigmaET. By employing a robust, powerful and accurate thermal simulation tool, engineers will minimise cost, increase reliability and time-to-market


between heat and performance. With components such as processors, for example, a design that tolerates and/or manages heat dissipation will allow for higher clock speeds. If the heat envelope is constrained, clock speeds will generally need to be reduced. Thermal modelling allows ‘tweaking’ for some optimum combination of heat and performance, or it can allow optimisation for one attribute or the other. Thermal simulation is, in essence, a specific variant of the technology developed for computational fluid dynamics (CFD), which uses the Navier- Stokes flow equations for viscous and heat-conducting fluids to model the way in which fluids flow around and through objects. To enable the simulation, the construction of a system or object needs to be represented as a mesh of grid cells. The quality of this grid is vital in achieving accurate solutions. Moreover, different thermal simulation software approaches grid cell generation in different ways.


A


merican investor, Warren Buffett, has made many insightful


comments, with my favourite being: “Risk comes from not knowing what you’re doing”. That’s no less applicable to the world of electronics design than it is to the world of stocks and shares. Today, more than ever before, companies are looking to eliminate risk – and cost – in everything they do. In designing new products, that’s eliminating the risk of failure; reduced reliability; customer dissatisfaction; late product introduction; and cost over-run, to name but a few.


THERMAL MODELLING Despite everything we know about electronics, each time we assemble electronics in a new way it’s something of an adventure into the unknown, and this is where the risk lies. Nowhere is that more true than with heat – the worst enemy of electronics in terms of its potential impact on performance and reliability. There are, of course, two ways of


finding out if a new product design will be adversely impacted by heat. The first is to develop prototypes on a ‘suck it and see’ basis until things appear to work out. The second – and, arguably, significantly more rational – approach is to simulate the heat characteristics of the design,


24 FEBRUARY 2015 | DESIGN SOLUTIONS / DESIGNSOLUTIONS


obviating the need for costly prototyping. Thermal modelling tools allow


electronics engineers to accurately forecast and understand the thermal characteristics of their designs, and to determine the best way to efficiently manage the heat generated by the equipment. Moreover, they enable the designer to develop a solid understanding of how temperature is distributed in a given design. That not only allows designs to be fine-tuned, but it also allows the development of products that are superior in terms of size and reliability. There is, however, always a trade-off


Thermal modelling tools allow electronics engineers to accurately forecast and understand the thermal characteristics of their designs


INTELLIGENCE The key to effective simulation is to provide a better way of optimising the grid to provide both performance and accuracy. An example of a sophisticated, yet easy to use, thermal modelling tool for the electronics industry is 6SigmaET. Announced originally five years ago, it has undergone significant revisions and upgrades, and is currently on Release 9. Release 9 integrates new levels of


With Release 9 of 6SigmaET, enhancements have been made to the user interface and functionality


intelligence, automation and ease of use to eliminate many of the issues that have afflicted analysis tools in the past. This is no longer just for specialists in thermal simulation, but is much more accessible to a wider community of design engineers. It also now includes object-based


gridding, with predefined gridding rules automatically deciding the best grid for any given simulation. Its new multi- level unstructured staggered grid solver


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44