b'Geek Hub | Engineer InnovationT=300.00sSelected GoalsC 300 ter five minutes of heating250Figure 1: Model of an200 face plot of egg afegg frying on a CPU in150 300Simcenter FloTHERM XT 200 250 Figure 3: Temperature sur100 25 texture onto the board. This allowed 0 50 75 100 150 the footprints of the board Figure 2: Temperature against time for egg cooled CPU An excessively detailed board is not Time components to be positioned Engineer Innovation | Geek Hub 25 accurately against the image.Solving complex thermal models withy for this model as we are Engineer Innovation | Geek Hub CFD requires a lot of processing powernecessarand a CPU under full load generates aonly interested in the CPU temperature. To do this, the model fair amount of heat. But can you cooky that may alter needs to include the major sources of an egg on it? Search online and youy around can find videos of people attempting toheat and any geometrJoin our Geek Hub! Geek Hub cook on their processors, but howllthe flow of air around critical This time.Frying an Egg on a CPU! effective as a cooling solution is this?components. The geometrthe CPU, such as the CPU socket, needs By James Forsyth, Engineering intern, Mentor, a SiemensBefore you throw away yourtunityto be much more detailed as this has a conventional heatsink and fan, in favory and a two-Geek Hub | Engineer Innovation of a multifunctional omelette, we significant effect on heat transfer by investigate what CFD in Simcenterconduction. The CPU itself is modeled Flotherm XT software can predictwith accurate geometrabout the fate of your PC if you do so. resistor network assembly thermal model, based on an Intel Corey Business i3-4130 as a representative mid-Model range desktop processor. Typical As a student intern at Mentor, ated bymaximum Tjunc and Tcase are Siemens Business I get the opporto create and play with interesting and90C and 72C. The geometrunusual thermal models made in thefar from the CPU, such as the I/O Are you passionate about y basic projectts, can be modeled as simple software. For this concept, I star porcuboids that will present an comprising two cuboids and a cylinder creating a ver obstacle to air flow on that edge to model a motherboard, processorof the board. Additional detail Engineering?and egg. Then I did some research would just prolong the solver standard dimensions for motherboards,computation time with diminutive CPU thermal design power (TDP),improvement in accuracy.Have you used your engineering skills to make something thermal data for eggs.y simple model, I wasOne consideration is that the egg able to test things rapidly, get a roughLimitationsUsing this ver cannot quite be simplified to a feel for the range of temperatures andmaterial with thermal63cool or fix a common problem?evaluate how feasible the concept wasproperties dependent on If so, send it into the Geek Hub and you could be featured temperature, which I then created a more detailed model, to model. ting a board usingSimcenter Flotherm XT is ADeasily capable of modeling. ting by impor For instance, apply heat to a in the next issue of Engineer InnovationFLOEDA Bridge, a tool in Simcenter star block of aluminum and that Figure 1: These images show how we discussed the dimensions of this device y to be produced from anenergy will all eventually be Flotherm XT that allows 3D C transferred to the ambient air intuitive 2D EDA environment. Using a Send your story and pictures towearer a much more natural andgeometrEngineer Innovation | Geek Hub economical walking motion. Thesetopographical image of a t, UK islimbs give the wearer much morerepresentative mITX motherboard and confidence to walk without the fear ofa selection of known dimensions, I was firstname.lastname@example.org, allowing them to get back to aable to accurately scale the image as a Every July, Hampton Cour more normal and active lifestyle.Geek Hub turned upside down as the RoyalBefore settling on her C-Leg, another Horticultural Society Flower Show Collaboration between twotouches down. The usually quiet(ish)prosthetic was trialed, the first one little town is transformed into awas far too heavy. The knee alone was gardeners haven. Quirky touches1.5kg thus making her prosthetic leg Engineers and a Marketingalong with beautiful planting coversweigh just over 6kg. Specialist to Simulate a Prosthesis. every available space. When Raylighter and allowed her to make the Edwards, founder of Limbcare,The second knee trialed was much informed Debbie Searle, Marketing Specialist at Mentor, A Siemensmost of the features provided by By Debbie Searle, John Wilson andbe at this years event, she championedthe micro-processor. The knee Business, that Limbcare were going toanalyzes gait and works out Mike Gruetzmacher a petition for Siemens to become awhat the knee is required to do. Gold sponsor of the Limbcare stand. ting a really goodIt allows Debbie to walk at Aside from suppor whatever speed she needs and cause, this event gave us a really goodcatches her if she stumbles. It opportunity to learn how technologyalso recognizes if she is walking can actually enrich lives. on slopes and ramps the resistance up or down. The brain behind all of Debbie lost her leg in 2015 due tothis is powerful and working62 Geek Hub | Engineer Innovationcomplications when she contractedconstantly. The engineering team Strep A. Later that year, with a lot ofwanted to see exactly how hard it was hard work, she was up and walking onworking and if that affected the a prosthetic with a mechanical kneeperformance of the prosthetic as a joint. These prostheses work well, butwhole.the big problem with them is that there71is a very high risk of falling. Unless youMike Gruetzmacher is the land your stride in the perfect position,Simcenter FLOEFD Software the knee has no resistance and willSpecialist for Mentor. Mike collapse, leaving the wearer on thecreated a model using the floor. hardware and technical details provided by Debbie, Just over two years later Debbieand additional new questions progressed to a micro-processor knee.put to her due to never These sophisticated knees house a PCB,Mike had to create another simulation battery, sensors and a resistancewith a lid to see how this changed the mechanism. The software analyzes theresults. We expected the temperature motion and speed of the wearer and isto rise, but we had to wait to see if this able to adjust the resistance to give thewould be a drastic increase."When Mike realized there was a lid missing from the model and the air are cool enough to eliminate the risk ofwas escaping through the top, he went facey, selected the face feels tooopen plane and with a few quick clicks injury. Many times the designback into the geometrrequirements for the outer sur created a lid to close the model at the y innovativetemperature are limited by how hot they high and unrealistic y and helpsurface feels. If a sur top. In an intermediate simulation, he having to deal with a prosthetic legwarm, the end user could interpret thisobtained ver d defined some of as a malfunctioning or poorly designedtemperatures. As he was making aties ways to explain the geometr unit. the solid components as an insulator before! Debbie found ver AD example andquick simulation, heEngineer Innovation | Geek Hub visualize the aim of the project (FigureviewAD andMike took a GrabC material. He also experimented byties per putting a heatsink on the PCB, and for 1). sformed some modifications until itts was neglected.Figure 4: Overlooked more like the physical board. Hethis comparison the material properWith the information gathered, Miketed into also applied some scaling features,for some of the par tant. The used a model found on GRABC because the initial unit was smaller.Now that the top of the leg is closed, modified it according to Debbie the influence of the material proper t.descriptions. Simcenter FLOEFD with the Simcenterbecomes more impor discomforThe IDF file was impor should not cause any burns or faces) werecombination of the closed top with Flotherm FloEDA Bridge so that the Once the first version was useable,y conditions (materials, heat 70 Mike shared this model with Johnboundar insulator material, caused the highThe information that can be gathered Wilson who created the PCB. John issources and radiative sur temperatures. Once this was realized, ais invaluable, without having to build AD, Johncreated automatically, see Figure 3.simulation was run for both cases withmultiple prototypes or having to the Electronics Product Specialist atThe ambient conditions were set tothe leg defined as standard stainlessredesign later on in the design process.ting from MC typical values of 20C and 1.01 bar.steel. The maximum temperature is Mentor, A Siemens Business. Gravity is enabled because it is cooledy small difference. The open almost equal in both cases, it shows ted with an image and with theby natural convection. only a ver www.limbcare.orgRather than star version is 0.1C cooler. What does thisFor more information:star yfaces show themean? Most of the heat is convecting help of Debbie, determined theflow approximate scales of the board andThe colored sur and radiating from the PCB to the outerDebbie Searle Blog: y/higher power dissipation components.temperature distribution on the PCB.https://bit.ly/2JJCztVpowered there is a need to develop aaround these components. It is causedReferencesWith electronics that are batter The arrows illustrate the air enclosure.y, putting on a lid and by the natural convection, whichIn summar https://grabcad.com/librarsolution that meets the functionalmeans the heated air moves upwardsenclosing the casing makes minimalsbelow-knee-prosthesis-1 nrequirements with the lowest powercausing air circulation in this area. impact. The maximum temperatures consumption possible. In thesereached in either case is 38C. The situations the critical IC componentsThe air is escaping out through the top,maximum advised temperature in a are well within their temperaturebut as our physical example has a lid,consumer product is around 41C. So at requirements (reliability of electronicsa little over body temperature, Debbieare strongly related to both peakleg, even while working at its hardest, temperature cycling). Thermal design operating temperatures and often involves ensuring that any73Figure 2: Board created faces that may be touched 66exposed surFigure 3: Boundary conditions of the PCB Figure 5: Temperature distribution on the PCB Figure 7: Comparison of the two variants72'