[Jason]

BIMMERPOST NEWS

The Role of Computational Fluid Dynamics in Development of the BMW M4 DTM

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March 30, 2017

Munich. When the six new BMW M4 DTMs take their place on the grid for the DTM season-opener on 6th May 2017, it will mark the temporary end of a long and intense period of development. A considerable part of this development took place with the aid of computer simulations. It is hard to imagine car development without computational fluid dynamics (CFD) these days.

During the creation of a new race car, the smallest details can bring about a decisive advantage in the battle for those fractions of a second on the circuit. It is no wonder that the BMW Motorsport engineers leave nothing to chance. That is why the CFD flow calculations are of such special importance. The development of digitalisation has changed racing car design. Engineers can identify the most promising solutions for specific components without leaving the computer.

On computers, the aerodynamics experts simulate the effects of changes to the individual parts of each car – before the components have even been built. In the calculation, the model is split into a grid of 500 million three-dimensional cells, and the virtual airflows through them. Each of the cells can be separately analysed, sometimes for an entire day, depending on the type of simulation. Only half of a vehicle is required, as the air flow for straight-line travel is identical for both sides of the car.

BMW Motorsport employs experienced aerodynamicists to interpret the calculated values. Despite the quality of the CFD simulation, the technical expertise of the aerodynamicists is still a decisive factor in drawing the correct conclusions from the results. After precise analysis of the pressure distribution, flow lines and many other details, the aerodynamicists can make a specific recommendation for changes to be made to the components. If the part has proved itself during simulation, variations are tested in the wind tunnel on a scaled down, 60 per cent model. The computer-aided flow simulation is not intended to replace wind tunnel work, but complements it.

The preliminary calculations are dealt with by an armada of high-performance computers. BMW Motorsport uses the BMW cloud system to dynamically adjust the number of computers in use, and adjust the load for other users within the BMW Group. This bandwidth and availability of computing power means that it is possible to perform multiple calculations in parallel. The result: even more efficiency and precision in the development of BMW Motorsport racing cars – like the new BMW M4 DTM.

[Yeru]

Kudos to the engineers. I say this as back in my college days, fluid dynamics would give us severe migraines

Developing this high performance computing software though is fun and fascinating!

[raysspl]

Real cool to see this

[mdputnam]

What follows is the conversation at the BMW Motorsport engineering center photo shoot between Hildegard Wortmann, head of BMW global marketing and Jens Marquardt head of BMW Motorsports...

Hildegard Wortmann: We can't use that engineer in a publicity shot! Look at his clothes! Someone, get rid of that pocket protector and loose the horned-rim glasses. He looks like a refugee from the 1970s!

Jens Marquardt: But, Hildegard that's how engineers dress. Besides, without his glasses he can't even find the keyboard.

Hildegard Wortmann: Get rid of him! And get me an engineer with style.

Jens Marquardt: We have none. All our other engineers are in their 40s and won't project BMW as a young dynamic company run by fun loving millennials for fun loving millennials.

Hildegard Wortmann: OK, at least put a BMW Motorsports jacket over that gawd awful polyester shirt.

[cbertels]

: I bet they said to themselves, should we use this on the present M6 race cars? No way, just paint "fast" on the side. That should do it!

[alz0rz]

Love how he's not actually doing anything and instead the screens just show an image opened in Windows Photo Viewer... to go along with the 'model' clothing mentioned above.

[wntrsnowg]

Originally Posted by alz0rz

Love how he's not actually doing anything and instead the screens just show an image opened in Windows Photo Viewer... to go along with the 'model' clothing mentioned above.

[Brake_Late]

Originally Posted by raysspl

Real cool to see this

Agreed

[mokrunka]

Originally Posted by alz0rz

Love how he's not actually doing anything and instead the screens just show an image opened in Windows Photo Viewer... to go along with the 'model' clothing mentioned above.

Actually, it looks like he has the CAD software pulled up on the right screen, with screenies on the left two.

[jafza412]

Yeah cool heat maps and air flow visuals, where can I find this jacket???

[GoHokiesGo]

Probably pressure distribution gradients in the images - most CFD programs require that you export jpeg picture files from your analysis plots, so its not too far fetched to believe he'd be reviewing results in a picture browser. The CFD guys that work for me usually give me 100's of pictures, along with a powerpoint highlighting key areas and scenarios.

[BSM n54iS]

You would think they could afford better looking keyboards and mouse, things look like what came with their old computers and they just replaced the monitors

[ouengineer]

Jealous of the three screens. I only get one at my current job (means I just print lots more stuff out...)