Boris Marovic’s Blog

Some interesting projects with FloEFD (I’m open for suggestions and helpful comments) and the world of FloEFD with the use and news in general purpose simulations. But also some things every now and then which crossed my mind.

24 December, 2014

Hello to all non-believers and believers. For those of you who do not believe in Santa and are looking for ways to prove that he does not exist, this post will show you some scientific reasons why he can exist. And for those who do believe in Santa, see this as prove to your believes.
As for me, well I like to believe in the spirit of Christmas and like to spend my time with family and friends and of course am happy for every gift no matter from whom.

First let’s set a few ground rules/thoughts for our arguments. We are living in a modern world where science changes our thinking and way of life from day to day. Just about 20 years ago the very first exoplanet was found and before that nobody knew what was out there and how many other worlds are there orbiting other stars. I can remember the day I saw it in my astronomy magazine as I was very much into space and the stars back then and had a nice 114mm Newton telescope. Today we know of 1855 planets with 473 multiple planetary systems and our strongest telescopes are exploring the skies and find hundreds of new planets every year (in February 2014 NASA announced the discovery of 715 new exoplanets).
So who’s to say that Santa is coming from earth and with that limited to our current technology?
Yes, he might look like an old white bearded man as we are told by our parents and grandparents but how do they know. And you might also know of the Grinch, a green (possibly furry) creature that hates Christmas. Couldn’t he be an alien?
And of course the typical human reaction is that an alien is evil so the natural reaction would be to make the Grinch evil. He might have been spotted by someone in front of the Christmas tree with a gift in his hand and the person thought “This evil alien wants to steal the wonderful gifts someone wanted to give to me.” And this rumor spreads making him the evil one but instead he was the one that placed it there and for the unknown bringer of gifts of course a nice older man with a beautiful white beard as they are usually friendly like everyone’s grandfather.
So with this foundation we have to think broad in the alien technology that might assist this “Santa” in bringing us our gifts and maybe also the fact of giving only to the good children who wouldn’t blame someone who’s green to be evil by nature :-)

But now let’s have a look at some major points that are used to prove that Santa does not exist.

  • There is no known reindeer race on earth that can fly!
    Assuming “Santa” crash landed somewhere near the north pole with his space ship, far away from any civilization. So after the crash his ship was mostly wrecked and he could only salvage some parts of its propulsion system, alloys, navigation system etc. Too little to get back home and enough to get around on earth. We all know in Star Trek there are inertia dampers for any shocks and vibrations, something that counteracts the rapid acceleration of an object and makes it possible to survive the acceleration to warp speed. This technology as well as the generation of the gravity on board of the space ship in some way are most likely based on a flexible gravity generator, reducing or increasing the gravity in the ship. Maybe “Santa” was able to somehow bring that onto some reindeers he found strolling near his crash site and make them fly this way, or it is just a gravity field he can create around his sled and the reindeers. Well we don’t know that how that works as we don’t understand the technology but we know that superconductors can levitate over a magnetic field which the earth basically has already. So who knows what we will be able to do in future if this is the state of the art today.
  • There are approximately 378 million children (for some religious reasons are Muslims, Jews, Hindus and Buddhists who are apparently not visited by Santa I heard, but I don’t think this is Santa’s view) to deliver gifts to within 31 hours (considering time zones), which is 822.6 visits per second considering an average of 3.5 children per household. This would result to fly with Mach 3,000 for an average house to house distance of 1.3km and an overall distance of 120.8 million km in the 31 hours he has on Christmas.
    Well considering the distance Santa travelled from his home planet to earth in a reasonable time, the distance on earth should be easy for him. But let’s have a closer look.
    The closest star system with an unconfirmed exoplanet is Alpha Centauri Bb with 4.36 light years distance and the closest with a confirmed exoplanet is 15.29 light years with actually four exoplanets orbiting the star named Gliese 876. Yes, a strange name but for Santa it might be some name we cannot even pronounce :-)
    Now according to Wikipedia, with Warp 9 he would be able to reach earth in less than a day from Alpha Centauri and about 3 days from Gliese 876, which is a reasonable travelling time and certainly much faster than 3,000 times the speed of sound. And who says he jumps actually through each chimney himself to deliver the presents. With technology such as in Star Trek he could easily beam the presents into a range of houses within the range of the transporter. This makes cleaning up the soot in the house from sliding through the chimney redundant.
    But we also know that jumping into warp speed within an atmosphere is not wise, but even with full impulse speed it is still ¼ of the light speed and therefore still much faster than required.
    Also considering other technologies such as from Doctor Who he would be able to travel through time or at least freeze time for a short period at once. As we know the time-space continuum is fragile so freezing it for too long or going back in time preventing him from stranding on earth would possibly cause catastrophic effects on our universe. But we could safely consider that he flies from village to village or city to city with full impulse, freezes time to have enough time to beam several presents at once into the houses of the families and then head to the other village or city.
  • The weight of the presents for all the children would be 378,000 metric tons considering a 1kg present per child. An average reindeer can pull not more than 175kg which would require 216,000 reindeers etc.
    Well we talked about Star Trek already and we all know they have the technology of replicators where the device can replicate any usual object such as a toy with ease. And since a few years 3D printer have reached public availability already, so who knows what will happen in future. Yes, at the moment we can only print from a material source we need to provide the printer of the same material already but in general all material consists of protons, neutrons and electrons and therefore it is generally possible to create a metal toy out of air with the right technology. So a huge storage in his sled is not necessary.
  • With the huge amount and weight of the presents at 3,000 times the speed of sound the drag force of the sled is enormous and will cause a massive heat just like the reentry into the atmosphere. The reindeer in the very front (Rudolph) will have to absorb something around 15 trillion joule of energy per second. The reindeer would immediately burst into flame and be incinerated within an instance and the following reindeers will suffer the same and it will create a massive sonic boom. The reindeers will be vaporized within a fraction of a second, Santa would be pinned to the back of his sled by the 17,500 g-forces acting on him and with an approximately 120kg weight he would be squished by his own body forces of 20.6 million Newton.
    Now considering we don’t have that much weight to carry and we have inertia dampers installed in the sled, the g-forces are not an issue as we can see in Star Trek. And of course every alien space ship just like the Enterprise in Star Trek has a force field to withstand the reentry temperatures. But even if not, maybe Santa’s technology is so far advanced that similar to the space shuttle he has some heat shield technology. That far advanced it might be something like a sun blocker spray or paint for his reindeers protecting them from the heat generated by the friction and the ionization effects appearing at such velocities. There certainly is some technology that will protect him and his reindeers from the heat.

So you might think “Oh what a weirdo of Trekkie is writing this post.” Well yes, I grew up with Star Trek and all the other Sci-Fi movies and TV series but we also know that such visionary thinking made researcher look to apply technology like that in reality. Laser cannons are in development and tested by the military to destroy incoming drones, planes and rockets. Beaming is already done, ok with by beaming the information of an atom over 1 meter from one atom to the other but that’s the first step into the future and Michio Kaku (one of the world’s most famous scientists) says that such teleportation device similar to those in Star Trek would be invented within 100 years.

So can you tell with 100% certainty that Santa is NOT real????
(And I’m not talking about magic or the force of god, but science we might have not yet reached to understand.)

Here’s a little simulation I did with a reindeer model in FloEFD where I added a red nose for Rudolph as he’s the leading reindeer. This is with a velocity of Mach 25 and you can see the temperatures reached at his nose. The iso-surface shows the shock front of the velocity of Mach 9. FloEFD considers friction heating and velocities up to Mach 30 for re-entry vehicles such as space shuttles into the atmosphere and is used by customers of us exactly for such re-entry calculations.
See the surface temperature on Rudolph and tell me your nose would not get red under such conditions :-)

Now the nose is either as usually the case sensitive and a little hot and stays that way, just like Obelix is always strong as he well into the magic potion pot when he was child, or it is another device that creates a heat source a little bit infront of him which causes the air to ionize and reduce the drag for him :-)

Rudolph the red-nosed reindeer Mach 30 Trajectories
Nose TemperatureMach 9 iso-surface front

Mach 9 iso-surface side Mach 9 iso-surface isometric

So considering he has a type of sun blocker on his fur and nose, the nose we know is always the most sensitive and since he is leading the reindeers his nose (as the most upfront body part in the flow) is the part that creates the shock cone breaking the sound barrier and therefore might get a little red even with “sun blocker” or a force field.

So with this happy holidays to all of you and may Santa bring you a lot of gifts for those of you who believe in him and for those who don’t… well don’t bring you anything as you don’t seem to need or want it ;-)


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10 June, 2011

Hello everybody,

I know it’s about time again, I was a little busy with LEDs lately, had some very interesting visits of customers working with LEDs and was working a webinar for use of LEDs in Automotive. You can click here to register now for this Automotive LED webinar.

But this time it is not about Automotive but about LEDs, I just happened to read an article about Applebee’s plan to switch to LED lighting to save energy, costs and the environment. In a test project they refurbished the Doylestown Applebee’s to LED lighting and predicted an investment payback in 11 month, reduce CO2 emissions by 630,000 lbs (286.000 kg) over the lifetime of the LEDs by reducing the electrical demand. The LEDs shall reduce the energy consumption by 440,000 kWh over the lifetime of the lights. That would be about the amount of 53 SUVs less on the streets. Since there are about 2,000 Applebee’s out there worldwide, imagine the savings. Ok, let’s do a calculation here, let’s assume the above mentioned values are the average if all 2,000 Applebee’s would use LED lighting, this would give the following values:

1,260,000,000 lbs (572.000.000 kg = 572.000 tons) of CO2 reduction by pure energy saving with a reduction of 880,000,000 kWh = 880 GWh which would be like taking about 106,000 SUVs off the road. Or if we consider shutting down a nuclear power plant as we won’t need the energy created by a nuclear power plant , we would be able to shut down the nuclear power plant “Nine Mile Point” near Oswego, NY as example (annual energy generation of about 14,000 GWh) for approximately 3 weeks. Of course this is over the life time of the lights, but this is only Applebee’s, now consider street lights, households factories and not to mention the fuel consumption and pollution from cars fi they were all equipped with LEDs. So just as a rough estimate, wouldn’t that save a huge amount of energy and ease the burden on our already heavily burdened environment?

Now when the investment pays back in 11 month, with an energy reduction of 440,000kWh and an average price of $0.15 per kWh, they would have saved about $66,000 or for all 2,000 Applebee’s that would be $132,000,000. That would be about 10% of their 2005 revenue and that in 11 month!

I found these numbers impressive! I know from myself that sometime people can be just too lazy to act on the simplest things such as switching the phone or electricity provider even if there is a cheaper one out there who would even provide us with a better product and in case of electricity even with green power. So if just everyone would just say “Hey, he’s right! Let’s switch our bulbs to LEDs.” then this would already be a huge improvement. But to be honest, I have one LED bulb at home. I thought I’ll try it and paid around 20 Euro and that’s a lot, but only if you think of it as the current purchase. Now think about how often you have to buy light bulbs and since in some countries light bulbs will disappear from the market over the next few years (that’s how it is in Germany, so for me) the alternative would be fluorescent bulbs, but I noticed a huge weakness of them: the don’t last very long if you only use light occasionally and not constantly. I bought two or three of them over the last few years and always noticed that the last about a year because you switch the light on when you enter a room and off again when you leave it after a few minutes such as the bathroom or bedroom. The are simply not made for such applications. Now with LEDs they don’t care really how often you switch them on and off and have instant full illumination power compared to the slow increasing power of fluorescent bulbs.

No I plan to get more LED lamps and bulbs over the time and with LEDs constantly improving, the efficiency of them is improving and making them even more economic and environment friendly.

If you want to learn more about LED thermal design in consumer applications, have a look on my webinar “Demystifying LED Design for Everyday Applications with Concurrent CFD”.

See you next time,


Note: All the data on revenue, electricity pricing and power plant output were done in Google and Wikipedia so no guarantee for that.

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8 February, 2011

Hi again,

I recently came across an interesting HVAC application of FloEFD, our CAD-embedded CFD package for concurrent product design, from one of our users in the Netherlands, Royal Boon Edam. I think it just shows how ubiquitous CFD has become in the world today when a manufacturer that was founded in 1873 as a carpentry workshop and has now grown into an international leader in the design and development of revolving doors, is using it to hone their products.


At Royal Boon Edam, like for most niche small and medium sized engineering companies in the Netherlands, innovation is of upmost importance and the company is continually aiming to improve and optimize its products. Ease of use and easy implementation of Computational Fluid Dynamics (CFD) into their design processes is a critical requirement for such companies.

As one might expect in the design of revolving doors, wind effects and wind loading on a given door and its component parts plays a significant role in its overall performance and for any Boon Edam installation worldwide they need to be able to design it to cope with any wind direction and urban canyon effect onsite. HEC, our Benelux distributor of FloEFD, worked with Boon Edam under a Dutch government scheme to carry out a large number of flow simulation permutations for the position of Royal Boon Edam door sets, their connections to a building’s facade (whether on a face or at a corner), the prevailing wind direction, the door’s canopy, and finally the number of leaves in a revolving door.

Royal Boon Edam Revolving Door with FloEFD Air Flow Pathline predictions near the door when the prevailing wind is approaching it head-on and side-on to the revolving door installation

This array of CFD simulations gave Royal Boon Edam tremendous design and engineering insights. “Worst case” examples based on wind forces on some of the components of the door for the maximum wind speed to be expected in the application considered over a range of wind directions was analyzed with a nominal wind load on doors in buildings of 250 Pa (20.4 m/s). FloEFD simulations showed that the actual wind pressure in the revolving door is typically lower than the pressure on the front of the building. Moreover, the shape of the revolving door has a positive influence making the allowable wind loads higher than expected.  CFD also looked at the influence of the position of the revolving door in the entrance area of the building for three wing doors and the effect of its connections to the facade of the building which has an impact on its canopy for wind loadings. All FloEFD models took into account the wind direction and the influence of the shape and size of the building the revolving doors were installed in. Dirk Groot, Product Manager at Boon Edam, summarized the benefits of this sort of CFD analysis with FloEFD quite well:

“We are extremely pleased with the results – In a relatively short period of time we have a better understanding of airflow and wind pressures around our doors and we can quantify our suspicions. This is in fact a new link between the Eurocode EN1991 and our theoretical structure calculations on the one hand, and the implementation of the actual product on the other.

So, my friends, with due apologies to Bob Dylan, it is clear that FloEFD helped Royal Boon Edam to find the CFD answer “blowin’ in the wind” for their revolving door designs!. More applications of FloEFD in the HVAC industry can be found here.





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18 November, 2010

Hello everyone,

I hope you missed me because I missed writing here and I know what I promised and my New Year’s pledge was not very helpful. The main reasons and not entirely bad excuses are some changes in my job right when I got back from my vacation I mentioned in my last post, therefore a lot of new work which I slowly get used to and fit in but also I moved and was busy with that during my vacation in summer. I was thinking several times on posting again but couldn’t find the time. So I’m terribly sorry for all of you waiting but I’m back finally. In the next time I might post a little bit more infrequently but this should get better over time.


For the start after the long break I wanted to comment on Nazita’s post on traveling by plane.

As an aerospace engineer I felt like she was talking of me when she described the situation where someone explained here the few-bolts-engine-hinge shocker :-)

I don’t assume that he also told her that there is a bolt called “Jesus-Bolt” usually found on sail planes. It’s the bolt fixing the vertical with the horizontal stabilizer with the elevator on it at a T-tail configuration. But also found in older Helicopter models or in the connection from the two joining wings on a sail plane for quick removal to be put into a transport box.

Well this bolt is named after the person you will prey to, will see or whose name you will scream if it fails. So every pilot flying one vehicle containing a Jesus-Bolt will definitely check that through the little window or hole prepared for that check, before flight.

I hope I didn’t ruin your interest in flying :-)

But let’s get to the thankful goodbye to the pilot after landing. In University we saw many things regarding capabilities of pilots. One really funny thing is the list of problems they reported to the ground crew (mechanics) after landing and the according answers of the ground crew on checking the issues. Here are a few of my favorites:

  • Pilot: Mouse in cockpit
    Crew: Cat installed.
  • Pilot: There is something lose in the cockpit.
    Crew: We tightened something in the cockpit.
  • Pilot: Dead fly on the windscreen.
    Crew: Living flies ordered.
  • Pilot: Engine 3 not present.
    Crew: Engine 3 found on the right wing after quick search.
  • Pilot: Test flight OK. Landing was pretty hard with autopilot.
    Crew: Landing with autopilot not installed in this aircraft type.
  • Pilot: Noise behind the instrument panel. Sounds like a dwarf hitting something with a hammer.
    Crew: We took the hammer from the dwarf.

Or some communication between the tower and pilots:

  • Tower: Are you a A320 or A340?
    Pilot: A340 of course!
    Tower: Then would you please start also the two other engines for take-off!
  • Pilot: Good morning Bratislava.
    Tower: Good morning. Just a hint: This is Vienna!
    Pilot: We are in approach for Bratislava now.
    Tower: This is really Vienna!
    Pilot: Vienna?
    Tower: Yes!
    Pilot: But why? We wanted to Bratislava.
    Tower: Okay. Then abort landing approach and fly left.
  • Tower: Height and Position?
    Pilot: I’m 1.80m and sitting in the front left.
  • Pilot: Requesting permission for take-off.
    Tower: Sorry, we don’t have your flight schedule. What’s your final destination?
    Pilot: Salzburg as every Monday.
    Tower: But today is Tuesday!
    Pilot: What? Then this is our day off.

Of course I have to add that these are some special cases and we all know everyone has a bad day every now and then. And I have some good friends who are pilots. So this was just something to cheer you up at a bad day or a bad flight :-)


But one more thing I heard yesterday in the radio. This falls into the category “Research the world doesn’t need!”.

American Scientists found out that if you poison ants they always fall over to their right. But they didn’t find out why.

I wonder how much money was put in this research study and maybe we should ask if the people in Haiti can somehow use this knowledge to fight their plague? Not to mention that it must have been of highest importance to answer this long awaited answer that we had to sacrifice lots of ants for it.

Wish you all a nice day and till next time (hopefully soon :-) )


23 February, 2010

Ok, last time I promised you to put a picture of me as Dr. Zoidberg from Futurama on here. Well here it is! What do you think? :-)

Dr. Zoidberg (Futurama)

Now back to the PC model. In the post before the last one I said I will show you the Mainboard and its main features. As you can see I modelled the heat sink in pretty good detail. I did that to show you a little feature of FloEFD™V5 or better said in all of our FloEFD products. But we will get to that when the time of simulating has arrived, but first more about the Mainboard. The Mainboard was at least at the time I bought it one of the newest of it’s kind. I has all the features such as DrMOS instead of Discrete MOS which means less power consumption, lower temperature of the MOS and more stable overclocking (in my case I didn’t overclock). A lot of very nice bright blue SMD LEDs for status displays on the board and some other nice to have features such as easy BIOS update etc. The main interest when modelling the Mainboard were the heat sources with heat sinks, all the card slots such as PCI-Express, DDR3 slots, Heat Pipe and the chip socket with chip. I cannot tell what kind of chip it is but it is a quad core with 2.67 GHz. I used also all six DDR3 slots with each occupied with a 2GB RAM module. The  Heat Pipe you can see is connecting the two chipsets  and the third heat sink which is not connected, the one close to the USB, LAN and other ports at the back side of the Mainboard is placed on the DrMOS.


Basic Mainboards Design in Catia V5

 Well this is how the Mainboards looks like with its most important features. The next thing I will do is to get some more information on the chips, for the definition of the heat sources and their material properties. So if this is done we could do a test calculation of the Mainboard without graphic card, RAM and the surrounding casing.

So, see you next time…

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11 February, 2010

First a happy new year to all of you even if it’s already a little late for that and second I’m terribly sorry for the long pause in my blogging but I was so busy in private and work life. My girlfriend is finally done with school and now veterinarian (horay!) and the last month were a little stressful with taking my dog with me to work and taking care of the household as long as she was busy studying. But now I found a little more time to start blogging again and yes I will continue with the PC simulation but not in this post, in the next post I will get back to the PC. But now I will definitely start blogging more regularly which was also my New Year’s pledge. BUT unfortunately I’ll be on vacation from mid to end of March and therefore probably about 3 weeks no posts but when I get back I want to share some nice vacation pictures with you.

 My vacation will be a two week trip from Oklahoma City to Las Vegas stopping on various locations in between. Some places I want to visit is White Sands, some nice spots along the Grand Canyon and of course I will visit some friends in Tucson from my thesis time there my sister and I really would like to see the moving rocks on the Nevada state border to California, but I have to see if the moving rocks will fit into the schedule. And especially for this trip I bought my first DSLR (digital single-lens reflex) camera. Before that I only owned compact digital cameras. I wanted to take some great shots because it is always a pity when you get home from great places and look at the pictures and they are not so good as it looked for your eye. So therefore I was training a little to work with the camera and learn how to use filters the best way to achieve great shots. Of course it’s not that easy to learn in a short time but I think I already learned a lot compared to the way someone would work with a regular compact camera. It’s a totally different way to take pictures with a DSLR. I never thought about the influence of all the settings such as aperture and it’s effects when making portrait pictures. Usually you would just take the picture and that’s it. But with consideration of having the background blurred and the important person you want to take the picture focused to stress out the important detail in the picture is not that normal to think about for someone with a simple camera in his hand. It’s more like “Oh, cool look at the building! <click> Ok lets go on.” Instead of trying to find an angle from which the building looks even more dominant or impressive, maybe from close to the street shooting up to it’s roof and therefore getting the gigantic impression or even other things a vacation photographer or layman as I was before never thought about with his compact camera they only take the shot and move on. Of course it is more time consuming but when you look on the pictures taken with passion and those just taken, it is a huge difference. I hope I can get some of these very nice shots that I can share with you. So that kind of photographing is really an art. If some of you still can remember or also just recently switched to DSLR, I would love to hear your first impression and confusion in the jungle of focal length and aperture you never thought about before using DSLR.

 Hey by the way, it’s high season for carnival in Germany right now. I went to the veterinarian carnival of the University of my girlfriend just recently and guess what costume I had! Dr. Ziodberg from Futurama :-) Some really liked the costume but others (mainly women) didn’t know where to put me or mistaken me for Mr. Krabs from SpongeBob. Honestly how could they mistake me for Mr. Krabs, they look totally different. I’ll have to post a picture of me in the next blog :-)

 Until then I wish you happy last few days of carnival and will get back to you with the project and a picture of me as Dr. Zoidberg.


13 August, 2009

Hello again,

Finally I was able to find some time for the project again. In the first part I showed you the CPU heat sink from Noctua and in this part I’ll show you how I gained the properties that I used for the simplified model of the heat sink. Instead of meshing the narrow space between the 36 metal sheets with a huge amount of cells in addition to the already lots of cells in the whole PC, I will use a porous media as a simplified model of it. Therfore I will need the properties of the porous media which is rather simple to do for some values but will need some calculations for others.

The first thing was to model a box around the heat sink to get an internal space for an internal analysis. Then I set up a project where I changed the computational domain to just a small cross-section perpendicular to the flow so I don’t have to create a lot of cells over the whole model, just a small sample frame is enough, and changed the sides to a symmetry or periodic boundary condition. Noctua was so kind to provide me for this blog Project with the fan curve which I will need later in the project to simulate the fan and also now to determine the flow rate that passes the porous media. Many thanks to Noctua again at this point! So I used just a small cross-section of 15x15mm and some area in front and behind the heat sink for an undisturbed flow. I applied the first volume flow rate to the inlet side of the box and the goals to receive mass flow rate and pressure drop between inlet and outlet by an equation goal. After meshing and adjusting the mesh settings to get an good mesh I cloned the project with results so I don’t have to mesh each cloned project again and save some time. This is very useful if you just change boundary condition values which doesn’t necessarily need re-meshing, except changing materials. So I cloned the project several times and with the help of the parameter editor I changed the volume flow rates so I have several values between the minimum and a little more than the maximum of the fan curve. With all projects set up I ran an batch run using one core (of an quad core computer) per project and with enough licenses you can run several projects simultaneously, in my case four simulations at the same time.

Now with the mass flow rate and the pressure drop I had the data I needed for the porous media definition from simulations, the others are just measured from the geometry. The porous media is defined by a porosity which basically is the ratio between the volume of the pores to volume of the whole block. So in my case the sheets are 0.5x15x58mm and I have fife of them in my little computational domain where the whole block that will become the porous media is 15x15x58mm so a ratio of 0.8333. Furthermore I set it to axisymmetrical since in the plane of the sheets (x and y-direction) the pressure loss will be the same but in z-direction I have the solid sheet metals so a infinite pressure loss. The reference length and area are needed to scale it to the later much larger size of the porous media. The reference length in radius (in-plane) direction has the 58mm and the area is 15x15mm, for the normal reference length I used 1mm and for the area 1x1mm so make it very little so the scaled values will get even larger and therefore relatively infinite. With values for the normal direction of 100bar for 0 and 100 kg/s volume flow rate so it is definitely very high and for all flow rates that will appear. It is also possible to use heat conductivity for porous medias as we will need it later in the project, otherwise it wouldn’t be a heat sink. The density of the porous matrix is therefore the ratio of the mass of all the sheet metals to the whole porous media volume. As material for the sheet metal I used Aluminum from our database also for the thermal properties in the porous media. The last property is the matrix fluid heat exchange definition which I left to zero for now since I don’t know it yet. We will find this out later when simulating the whole PC until then no heat exchange between solid and fluid is taking place in the porous media.

With the properties of the porous media I can now replace all the heat sink sheet metals with one block of the same size that represents the heat sink as porous media.

So that’s it for today and next time I’ll show you how I modelled the motherboard with chipsets and their heat sinks and PCI slots etc.

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5 August, 2009

Have you heard or read that soon there will be no more old fashion light bulbs in EU countries? What would Thomas Edison say if he knew that the biggest invention he made will become extinct in the EU. Would he turn in his grave or would he welcome the change to newer innovative technology that is more energy saving and efficient? I think as an innovative inventor he was he would welcome it since every smart inventor and designer is constantly working on improving his product. It’s like a non-biological evolution. And I would say also Darwin’s law applies to the non-biological world. Its either eat or be eaten (survival of the fittest). So it is more of an evolutional step from the light bulb to energy saving bulbs or LED – well not exactly bulbs but I think you know what I mean. Evolution is something good things adapt to their environment and therefore getting better if it’s in efficiency or in reproduction. For example, have you heard of some birds mimicking a little bit ring tones of cell phones? With these new calls the bird is more of an exotic attraction to its female counterpart than the old fashion male and wil have more success in reproduction.

Well ok, there are good and bad ways evolution can be triggered. It can be a bad way if mankind is causing the wildlife into a new evolutionary step especially if we are forcing it too fast by changing the environment faster than the animals and plants can adapt and therefore will face extinction in the worst case or reduced to an endangered species until they adapt to their new environment. Some – lets say pessimists – say evolution can be expensive and are refusing to adapt. You can see what happens when looking on your mother and maybe also father of higher ages, they usually cannot make heads and tails out of all the new technology such as DVD and HD recorders, DSL and multi processor computers. But some of you might have a father who was always into technology and doesn’t have a problem with the new stuff. Hehe, when I think of my Mom, she called me just yesterday and said here computer won’t start anymore. It seems to show a blue screen with white text on it and she doesn’t know what to do. Well since I’m not that close to here home I cannot simply drive over and fix the problem but every now and then something else happens, here HD recorder is not working or her WLAN. Funny how someone easily fixes the problem who is staying on the technology wave and other who stopped chasing it is getting left behind and it can be a really fast wave sometimes.

But back to the bulbs… I think Australia did a great job in forcing to switch to the energy saving bulbs. Of course they are more expensive and have a shorter life time if always switched on and off but this will change. When thinking back to the time the first LCD and TFT displays came to market, they were so expensive and only 14″ LCD were relatively affordable but today the production processes have improved and made it all more affordable not only because of the technology in the production process but also because people bought more and more LCD and TFT so there was a change that forced the prices to go down and improve the production. When you think of these limited sports cars that are almost hand crafted, they are also very expensive and therefore an exclusive item for rich people. But imagine a mass production of these cars. The price would plummet from lets say 250,000 Euro to 100,000 Euro. The first LCDs had a pretty high error rate of pixels and so a lot of displays were to bad to sell but the process improved and so they became cheaper. Today the CRT displays became extinct, well not every workplace has a TFT yet, but try to buy a CRT display in a shop today ;-) If you go into a computer store in a few years and want to buy a CRT display the young sales person (just turned 18) might throw a questioning look at you and ask “You want to buy a what?”

Sometimes I can’t wait to see what the future holds and am amazed about the abilities of new technology. So we all better stay on the wave of technology to not get washed aside.

Until next time…

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21 July, 2009

You might think “he’s gone crazy now” when you read the header but it basically is true. When talking about quantum physics some might think of names such as Heisenberg, Einstein and Schrödinger besides many other very good scientists. You might think that you are using FloEFD or FloTHERM for pumps, valves or any electronic cooling applications but how are you using quantum mechanics with it. Well this is basically very simple, we are not really going into quantum mechanics with the Flo* products but we have the same problems as they are described with Heisenberg uncertainty principle or Schrödinger’s cat experiment. Please don’t panic, you don’t have to go to school again and do a major in quantum physics, I’ll show you what I’m talking about.

Heisenberg uncertainty principle states that certain pairs of physical properties cannot be known to a 100% precision for both at the same time. For example it is not possible to measure the position and the velocity of an microscopic particle at the same time to a 100% accuracy because by measuring the position of the particle we would disturb the flow and therefore change the speed of the particle and vice versa.

So to transfer it to all the Flo* users applications… How would you know the pressure, velocity, temperature or any other physical parameter in your prototype? Correct, you’ll have to measure it. But often measuring it is hard since you don’t want to disturb the system and cause different results than the product would have without measuring it. That’s why some of our customer are working with the Flo* products to build measuring equipment such as pressure or concentration sensors that will not disturb the actual flow too much, all that to bring you measurement equipment that has the least effect on the your flow.

Schrödinger’s cat is a more hypothetical experiment (we don’t want you to start killing cats). This experiment was intended for a more complicated theory (Copenhagen interpretation) but is used as a touchstone in many interpretations of quantum mechanics. So in our case we can put the cat in a box with a liquid that reacts on a certain environmental influence such as light, a chemical element or a certain gas and release a toxic gas. Now put the cat in a box so everything is sealed from light and any other outside source that might bring the liquid to release the deadly gas which would kill the cat. So how would you know if the cat is still alive? If you open the box and have a look the gas would be released and the cat dies but would the cat have survived if you wouldn’t have opened the box? Who knows? This is principally the Schrödinger’s cat experiment applied to the Heisenberg uncertainty principle. By measuring the experiment (checking if the cat is still alive) we might change the result.

So every time you are trying to measure the velocity with a probe or the pressure you will disturb the flow just like in the Schrödinger’s cat experiment and often it is not very easy or cheap to measure in an enclosed system. Imagine a large and expensive autoclave or build and measure every prototype in which you made small changes in order to improve its efficiency. This is often very time consuming an expensive and by simulating your product you save money, time and don’t disturb the flow.

So altogether, don’t you think by doing a “quantum” mechanical analysis you safe a “quantum” of money and time and improve your products by a “quantum” in efficiency? I think you deserve to think of yourself as a quantum physicist equal person. After all you’re creating world changing and improving products to safe energy and with that creating green products which nowadays gets more and more important. So at least in our eyes all Flo* users are very smart by choosing to use our products to improve the world. So what’s the difference between smart engineers that change our world today and smart scientists that change our world in the future. I would say there is no difference since only if we keep saving energy today there can be a world in the future for things such as quantum computers and other products based on the quantum physics science.

Keep changing the world (and to say it with the words of one of the best popstars ever) “make it a better place, for you and for me and the entire human race”

Until next time…

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14 July, 2009

Well this is great, after some really busy weeks I wanted to give a good advice to all FloEFD users (and of corse the other Flo* products users) and I have to see that Robin already did. But anyway I want to point this out too.

Did you ever wonder if you can have any influence in the development of software you are using. Take the Microsoft Office products for example, do you think you can have any influence in a product as big as this in the way of handling it, in new features you want to have in the software? I don’t know if Microsoft has an email address on where to send enhancement suggestions so I don’t want to say you cannot influence them but when you think about it, you can get the feeling you are just a little user that no one can hear when screaming for an certain enhancement you could need really badly. But hey, you have the right to get heard and involved in the development process. After all, you are buying the software and using it. Imagine you have bought a new really nice car and there is some problem with, lets say something non-lethal than the brakes :-) , the steering wheel it is going really hard and you wouldn’t have the right to get it fixed or in our case improved with a better bearing or what ever would solve the problem. Ok, that would be more of a bug than an enhancement, but I think you catch my drift.

As an engineer who works in the support we regularly receive calls from customers asking if this or that is possible with FloEFD and if not we can forward an enhancement to our developers and we gladly do this since you are the expert in your field and know what is needed to simulate or visualize your models. But when we forward the enhancement, how would you know we really did it (not that we won’t, but do you know it?) or you would again get the feeling you are the only one who needs this enhancement and why should we listen to you “little” user out of thousands of other users around the world. Well there is one way to make sure your enhancement is getting seen by the developer team and to see if you are really the only one who need this. Log on to your SupportNet website and see in the bottom left column the blue “Mentor Ideas” field. Simply click on it and you can create yourself a profile and post your enhancement suggestion. But not only post your suggestions, you can also vote for other suggestions so they are climbing up in the ranking list and with that helping our developers to see which enhancement is of high interest for our customers.

As you can see you are not only heard, others can also vote for your suggestions so you can see that it was a good one and you can comment on other suggestions and your own. How’s that, having the feeling that it is YOUR FloEFD you use. Our developer team will comment on you suggestions if they are possible or ask you for more details etc. Pleas try to use this really good tool to make FloEFD the way you want it to be with features you need to simulate your applications and if your not a native English speaker or think your English is not good enough, don’t hesitate and ask your support engineer to write an enhancement suggestion for you on Mentor Ideas either anonymous or with company and/or your name to see how your idea is welcomed in the world of other FloEFD users.

I can only encourage you, and remind you again:

It is YOU who bought FloEFD, it is YOU who uses FloEFD and who else can help us better than YOU to make FloEFD more suitable to YOUR needs if not (who would have guessed it?) YOU!”

So please help us and yourself improving FloEFD in usability and suitability for your needs.