© Mercedes-AMG Petronas Motorsport

Mastering the Air

While searching for perfect aero­dy­namics, Mercedes-AMG Petronas Motor­sport and ebm-papst rely on simu­la­tions, tests and constant improve­ment.


Optimal aero­dy­namics is a key require­ment for the success of both Mercedes-AMG Petronas Motor­sport and ebm-papst. “Both know how impor­tant airflow is to perfor­mance”, explained Geoff Willis, Tech­nology Director at Mercedes-AMG Petronas Motor­sport. “Where our aero­dy­namic focus is on achieving high levels of consis­tent down­force, the focus on a fan is to improve airflow in the most effi­cient way possible”. Even though the Formula One team and ebm-papst have different chal­lenges, the part­ners use similar approaches for imple­menting constant improve­ment. “The Formula One team and us use the same tools: on the one hand, numer­ical resources and soft­ware programs for simu­la­tion. On the other hand, exper­i­menting with models and real prod­ucts”, said Dr. Jürgen Schöne, Head of the Aero­dy­namics Depart­ment at ebm-papst in Mulfingen.

Even though the Formula One team and ebm-papst have different chal­lenges, the part­ners use similar approaches for imple­menting constant improve­ment. “The Formula One team and us use the same tools: on the one hand, numer­ical resources and soft­ware programs for simu­la­tion. On the other hand, exper­i­menting with models and real prod­ucts”, said Dr. Jürgen Schöne, Head of the Aero­dy­namics Depart­ment at ebm-papst in Mulfingen.

Simu­la­tions: Airflow by numbers

Due to the great degree of freedom they provide, simu­la­tions are an impor­tant compo­nent of both part­ners’ devel­op­ment processes. ebm-papst uses simu­la­tion tools to compress the devel­op­ment period and discover tech­no­log­ical poten­tial that would other­wise remain hidden. “Numerics allow us to explore a much greater number of vari­a­tions that we could ever hope to examine using an exper­i­mental approach. In this way, we have the oppor­tu­nity to arrive at very different geome­tries and improve­ments,” explained Schöne.

Airflow simu­la­tion using a venti­la­tion tech­nology unit with RadiPac.

With CFD simu­la­tion, engi­neers at ebm-papst calcu­late the aero­dy­namic prop­er­ties of impellers, for example. The RadiCal, a centrifugal fan that is ideal for many venti­la­tion and air condi­tioning appli­ca­tions, was the first “synthet­i­cally devel­oped” product created in that manner.

Simu­la­tions help Mercedes-AMG Petronas Motor­sport to improve its under­standing of the complex airflows around a Formula One car and study which aero­dy­namic conse­quences even the smallest changes have. The team uses the infor­ma­tion to adjust the car opti­mally to the rele­vant track, for example. Willis explains: “The airflow over a Formula One car is very intri­cate and diffi­cult to tame: swirling vortices that interact with each other, compli­cated flows around rotating wheels, and small changes in car atti­tude as it accel­er­ates, brakes or turns. The key to success is having a thor­ough under­standing of the many complex flow struc­tures. This knowl­edge is built up using a combi­na­tion of compu­ta­tional simu­la­tions (CFD) and exper­i­mental results from the wind tunnel and from the track.”

Exper­i­ments: The moment of truth

While Mercedes-AMG Petronas Motor­sport goes to the wind tunnel or race­track for its tests, the engi­neers from ebm-papst use combi­na­tion tunnels in which both air perfor­mance and noise can be measured. “For us, the most impor­tant goal of exper­i­ments is veri­fi­ca­tion of the values derived from simu­la­tions. After all, even today’s results are not perfect – and do not reflect the absolute truth,” said Schöne. “And we also conduct exper­i­ments in order to study the behavior of our fans in complex customer prod­ucts or to take a closer look at their acoustics. There actu­ally are some simu­la­tion tools for this purpose, but they are still in the devel­op­ment phase.”

“For us, the most impor­tant goal of exper­i­ments is veri­fi­ca­tion of the values derived from simu­la­tions. After all, even today’s results are not perfect – and do not reflect the absolute truth.”

Dr. Jürgen Schöne, Head of the Aero­dy­namics Depart­ment at ebm-papst in Mulfingen

Results from the wind tunnel are just as impor­tant for Mercedes-AMG Petronas Motor­sport as a means of veri­fying the find­ings of simu­la­tions. “Because of the complex nature of the flows involved, CFD some­times strug­gles to give us a truly accu­rate simu­la­tion of what actu­ally happens. The wind tunnel gives us a closer repre­sen­ta­tion of what happens on the car”, explained Willis. The rules the Formula One team are subject to during their tests result in a major differ­ence between the ways ebm-papst and Mercedes-AMG Petronas Motor­sport work.

The engi­neers from ebm-papst run exper­i­mental tests to verify the results of their simu­la­tions.

Aero­dy­namics experts with expe­ri­ence

“We are limited by the regu­la­tions on the scale and wind speed we can test at, and a scale model at reduced speed will never fully repli­cate the physics of what happens at the track,” said Willis. This is why the Formula One team relies on expe­ri­enced aero­dy­namics experts to inter­pret the find­ings of the wind tunnel exper­i­ments, simu­la­tions and the handful of test days they have avail­able. At ebm-papst, the aero­dy­namics experts are usually asked to contribute their expe­ri­ence when it comes to adapting prod­ucts to opti­mally serve customer appli­ca­tions. The better they pave the way, the more effi­cient the overall devel­op­ment process.

“The under­standing of aero­dy­namics that ebm-papst have is one of the key reasons they are on top of their game with regards to cooling solu­tions.”

Dr. Jürgen Schöne, Head of the Aero­dy­namics Depart­ment at ebm-papst in Mulfingen

Willis describes how they are successful: “The under­standing of aero­dy­namics that ebm-papst have is one of the key reasons they are on top of their game with regards to cooling solu­tions. Getting the aero­dy­namics right is crucial for a race car, but also for a fan so that it can be as effi­cient as possible”.

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