Aerodynamic Simulation Reveals Best Position in a Peloton of Cyclists

July 5, 2018

Professor Bert Blocken, Eindhoven University of Technology (TU/e) and KU Leuven is recognized worldwide for his thorough scientific investigations about elite cycling sport. His research helps to better understand, among others, the best downhill position to adopt by a cyclist, aerodynamic benefits provided by a following car or motorbikes, which are all conditions that impact the result of the race. In a new 2018 project, Professor Bert Blocken conducted the largest numerical simulation ever done in the sport industry and cycling discipline. The goal was to understand the aerodynamic interactions in the entire peloton revealing unexpected results.

The cyclist pushes air in front of him (red) and creates a depression in its back. This air resistance induces the drag.

The simulation results confirm that the best position is in the core of the peloton close its head, row 12 to 14; but the computer models surprisingly calculates that the drag experienced by the athletes in this position is 10 to 20 times less than for an isolated cyclist; so far the scientific community considered that the drag was only 2 or 3 times smaller in the peloton.

While biking, cyclists push air in front of them creating an over pressure (in red) and a depression in its back (blue); this air resistance that the athlete continuously has to fight is known as the drag.

Because of the aerodynamic interactions with the surrounding cyclists, the athlete at the center of the pack is literally entrained by the peloton induced air motion. Using ANSYS Fluent running on a Cray, the largest computer model ever done with 3 billion cells to accurately predict the flow pattern in between each cyclist of the peloton enables Prof Bert Blocken to create a complete map of the drag experienced by all cyclists. Compared to the drag of an isolated cyclist the air resistance experienced at the core of the peloton is reduced by up to a factor 20! (down to 5% of an isolated cyclist): it is approximately 4 times easier to bike at the core of the peloton than alone.

Map of the drag reduction compared to an isolated cyclist; circled in red is the best position with favorable aerodynamic conditions while staying close to the head of the race.

“We are closely collaborating with elite athletes who want to benefit from advanced technology. These results teach them how important it is to stay well sheltered in the peloton as long as possible: you save a lot of energy and remain fresh until the final rush of the race” explains Prof Bert Blocken (TU/e and KU Leuven). He added “These results were so surprising that we also set up a wind tunnel test and successfully validated the numerical results with the largest wind tunnel experiment we have ever done”.

“Supercomputers handle the most challenging simulation, analytics and AI workloads imaginable,” said Dominik Ulmer, director of Operations in EMEA at Cray. “Because Cray systems deliver extreme scalability and performance, they are essential to gaining better understanding of complex problems.”

“In a time when simulation is crucial to accelerate and amplify innovation for High Tech industries, the peloton project and is surprising results illustrate that this simulation technology is truly pervasive and can make a huge difference in a popular sport such as cycling,” concludes Thierry Marchal, Global Industry Director for Sports and Healthcare at ANSYS.

An experimental wind tunnel validation confirms the surprising results revealed by the large CFD computer model. The yellow cyclist identifies one of the very advantageous positions with 5 to 10% calculated drag.

About Professor Bert Blocken

Prof. dr. ir. Bert Blocken is a Civil Engineer holding a PhD in Building Physics. He is Full Professor in the Department of the Built Environment at Eindhoven University of Technology (TU/e) in the Netherlands and part-time Full Professor in the Department of Civil Engineering at KU Leuven in Belgium. His main areas of expertise are urban physics, wind engineering and sports aerodynamics. He developed TU/e’s first Massive Open Online Course (MOOC) entitled “Sports & Building Aerodynamics” on the Coursera platform. He has published 148 articles in international peer-reviewed journals. He has received the 2013 Junior Award from the International Association of Wind Engineering and six best paper awards from the Elsevier ISI journal Building & Environment (2009, 2011 and 2012) and at international conferences. According to the 2016 Academic Ranking of World Universities (Shanghai Ranking) & Elsevier, he is among the 150 most-cited researchers worldwide both in the field of Civil Engineering and in the field of Energy Science & Engineering. He is an Editor of the journal Building & Environment and Associate Editor of the Journal of Wind Engineering & Industrial Aerodynamics. He is member of the editorial board of the journals Building Simulation and Sports Engineering. He has acted as a reviewer for more than 70 different ISI journals. He is currently supervising a team of 4 senior researchers, 25 PhD students and 4 MSc students.

In previous years, the lead researcher professor Bert Blocken and his co-workers also investigated (see figure below):
● The aerodynamic benefit for a first cyclist followed by a second one
● The aerodynamic benefit for a cyclist by a following car
● The aerodynamic benefit for a cyclist by a following motorcycle
● Which cycling hill descent position is aerodynamically superior (focused on the downhill position by Chris Froome in the 2016 Tour de France – Peyresourde descent)

All these studies were performed with the same methods (ANSYS CFD and wind tunnel research); they were published in top scientific journals (see files on USB drive). An article discussing the Peloton study will be published soon in a leading scientific journal.

About TU Eindhoven

Eindhoven University of Technology (TU/e) in the Netherlands is a research university specializing in engineering science & technology. Our education, research and knowledge valorization contribute to science for society (solving the major societal issues and boosting prosperity and welfare), science for industry (the development of technological innovation in cooperation with industry) and science for science (progress in engineering sciences through excellence in key research cores and innovation in education). The research group Wind Engineering & Sports Aerodynamics led by Professor Bert Blocken of the Department of the Built Environment focuses on numerical simulation with Computational Fluid Dynamics (CFD), wind-tunnel testing and field measurements for fundamental and applied research in buildings and city aerodynamics and sports aerodynamics. Visit http://www.urbanphysics.net for more information.

About ANSYS, Inc.

If you’ve ever seen a rocket launch, flown on an airplane, driven a car, used a computer, touched a mobile device, crossed a bridge or put on wearable technology, chances are you’ve used a product where ANSYS software played a critical role in its creation. ANSYS is the global leader in engineering simulation. Through our strategy of Pervasive Engineering Simulation, we help the world’s most innovative companies deliver radically better products to their customers. By offering the best and broadest portfolio of engineering simulation software, we help them solve the most complex design challenges and create products limited only by imagination. Founded in 1970, ANSYS is headquartered south of Pittsburgh, Pennsylvania, U.S.A., Visit www.ansys.com for more information.

About Cray, Inc.

Cray Inc. (Nasdaq:CRAY) combines computation and creativity so visionaries can keep asking questions that challenge the limits of possibility. Drawing on more than 45 years of experience, Cray develops the world’s most advanced supercomputers, pushing the boundaries of performance, efficiency and scalability. Cray continues to innovate today at the convergence of data and discovery, offering a comprehensive portfolio of supercomputers, high-performance storage, data analytics and artificial intelligence solutions. Go to www.cray.com for more information.

Subscribe to HPCwire's Weekly Update!

Be the most informed person in the room! Stay ahead of the tech trends with industy updates delivered to you every week!

Insights from Optimized Codes on Cineca’s Marconi

February 15, 2019

What can you do with 381,392 CPU cores? For Cineca, it means enabling computational scientists to expand a large part of the world’s body of knowledge from the nanoscale to the astronomic, from calculating quantum effe Read more…

By Ken Strandberg

What Will IBM’s AI Debater Learn from Its Loss?

February 14, 2019

The utility of IBM’s latest man-versus-machine gambit is debatable. At the very least its Project Debater got us thinking about the potential uses of artificial intelligence as a way of helping humans sift through al Read more…

By George Leopold

ClusterVision in Bankruptcy, Fate Uncertain

February 13, 2019

ClusterVision, European HPC specialists that have built and installed over 20 Top500-ranked systems in their nearly 17-year history, appear to be in the midst of bankruptcy proceedings. According to Dutch news site Drimb Read more…

By Tiffany Trader

HPE Extreme Performance Solutions

HPE Systems With Intel Omni-Path: Architected for Value and Accessible High-Performance Computing

Today’s high-performance computing (HPC) and artificial intelligence (AI) users value high performing clusters. And the higher the performance that their system can deliver, the better. Read more…

IBM Accelerated Insights

Medical Research Powered by Data

“We’re all the same, but we’re unique as well. In that uniqueness lies all of the answers….”

  • Mark Tykocinski, MD, Provost, Executive Vice President for Academic Affairs, Thomas Jefferson University

Getting the answers to what causes some people to develop diseases and not others is driving the groundbreaking medical research being conducted by the Computational Medicine Center at Thomas Jefferson University in Philadelphia. Read more…

South African Weather Service Doubles Compute and Triples Storage Capacity of Cray System

February 13, 2019

South Africa has made headlines in recent years for its commitment to HPC leadership in Africa – and now, Cray has announced another major South African HPC expansion. Cray has been awarded contracts with Eclipse Holdings Ltd. to upgrade the supercomputing system operated by the South African Weather Service (SAWS). Read more…

By Oliver Peckham

Insights from Optimized Codes on Cineca’s Marconi

February 15, 2019

What can you do with 381,392 CPU cores? For Cineca, it means enabling computational scientists to expand a large part of the world’s body of knowledge from th Read more…

By Ken Strandberg

ClusterVision in Bankruptcy, Fate Uncertain

February 13, 2019

ClusterVision, European HPC specialists that have built and installed over 20 Top500-ranked systems in their nearly 17-year history, appear to be in the midst o Read more…

By Tiffany Trader

UC Berkeley Paper Heralds Rise of Serverless Computing in the Cloud – Do You Agree?

February 13, 2019

Almost exactly ten years to the day from publishing of their widely-read, seminal paper on cloud computing, UC Berkeley researchers have issued another ambitious examination of cloud computing - Cloud Programming Simplified: A Berkeley View on Serverless Computing. The new work heralds the rise of ‘serverless computing’ as the next dominant phase of cloud computing. Read more…

By John Russell

Iowa ‘Grows Its Own’ to Fill the HPC Workforce Pipeline

February 13, 2019

The global workforce that supports advanced computing, scientific software and high-speed research networks is relatively small when you stop to consider the magnitude of the transformative discoveries it empowers. Technical conferences provide a forum where specialists convene to learn about the latest innovations and schedule face-time with colleagues from other institutions. Read more…

By Elizabeth Leake, STEM-Trek

Trump Signs Executive Order Launching U.S. AI Initiative

February 11, 2019

U.S. President Donald Trump issued an Executive Order (EO) today launching a U.S Artificial Intelligence Initiative. The new initiative - Maintaining American L Read more…

By John Russell

Celebrating Women in Science: Meet Four Women Leading the Way in HPC

February 11, 2019

One only needs to look around at virtually any CS/tech conference to realize that women are underrepresented, and that holds true of HPC. SC hosts over 13,000 H Read more…

By AJ Lauer

IBM Bets $2B Seeking 1000X AI Hardware Performance Boost

February 7, 2019

For now, AI systems are mostly machine learning-based and “narrow” – powerful as they are by today's standards, they're limited to performing a few, narro Read more…

By Doug Black

Assessing Government Shutdown’s Impact on HPC

February 6, 2019

After a 35-day federal government shutdown, the longest in U.S. history, government agencies are taking stock of the damage -- and girding for a potential secon Read more…

By Tiffany Trader

Quantum Computing Will Never Work

November 27, 2018

Amid the gush of money and enthusiastic predictions being thrown at quantum computing comes a proposed cold shower in the form of an essay by physicist Mikhail Read more…

By John Russell

Cray Unveils Shasta, Lands NERSC-9 Contract

October 30, 2018

Cray revealed today the details of its next-gen supercomputing architecture, Shasta, selected to be the next flagship system at NERSC. We've known of the code-name "Shasta" since the Argonne slice of the CORAL project was announced in 2015 and although the details of that plan have changed considerably, Cray didn't slow down its timeline for Shasta. Read more…

By Tiffany Trader

The Case Against ‘The Case Against Quantum Computing’

January 9, 2019

It’s not easy to be a physicist. Richard Feynman (basically the Jimi Hendrix of physicists) once said: “The first principle is that you must not fool yourse Read more…

By Ben Criger

AMD Sets Up for Epyc Epoch

November 16, 2018

It’s been a good two weeks, AMD’s Gary Silcott and Andy Parma told me on the last day of SC18 in Dallas at the restaurant where we met to discuss their show news and recent successes. Heck, it’s been a good year. Read more…

By Tiffany Trader

Intel Reportedly in $6B Bid for Mellanox

January 30, 2019

The latest rumors and reports around an acquisition of Mellanox focus on Intel, which has reportedly offered a $6 billion bid for the high performance interconn Read more…

By Doug Black

US Leads Supercomputing with #1, #2 Systems & Petascale Arm

November 12, 2018

The 31st Supercomputing Conference (SC) - commemorating 30 years since the first Supercomputing in 1988 - kicked off in Dallas yesterday, taking over the Kay Ba Read more…

By Tiffany Trader

Looking for Light Reading? NSF-backed ‘Comic Books’ Tackle Quantum Computing

January 28, 2019

Still baffled by quantum computing? How about turning to comic books (graphic novels for the well-read among you) for some clarity and a little humor on QC. The Read more…

By John Russell

Contract Signed for New Finnish Supercomputer

December 13, 2018

After the official contract signing yesterday, configuration details were made public for the new BullSequana system that the Finnish IT Center for Science (CSC Read more…

By Tiffany Trader

Leading Solution Providers

SC 18 Virtual Booth Video Tour

Advania @ SC18 AMD @ SC18
ASRock Rack @ SC18
DDN Storage @ SC18
HPE @ SC18
IBM @ SC18
Lenovo @ SC18 Mellanox Technologies @ SC18
NVIDIA @ SC18
One Stop Systems @ SC18
Oracle @ SC18 Panasas @ SC18
Supermicro @ SC18 SUSE @ SC18 TYAN @ SC18
Verne Global @ SC18

Deep500: ETH Researchers Introduce New Deep Learning Benchmark for HPC

February 5, 2019

ETH researchers have developed a new deep learning benchmarking environment – Deep500 – they say is “the first distributed and reproducible benchmarking s Read more…

By John Russell

ClusterVision in Bankruptcy, Fate Uncertain

February 13, 2019

ClusterVision, European HPC specialists that have built and installed over 20 Top500-ranked systems in their nearly 17-year history, appear to be in the midst o Read more…

By Tiffany Trader

IBM Quantum Update: Q System One Launch, New Collaborators, and QC Center Plans

January 10, 2019

IBM made three significant quantum computing announcements at CES this week. One was introduction of IBM Q System One; it’s really the integration of IBM’s Read more…

By John Russell

Nvidia’s Jensen Huang Delivers Vision for the New HPC

November 14, 2018

For nearly two hours on Monday at SC18, Jensen Huang, CEO of Nvidia, presented his expansive view of the future of HPC (and computing in general) as only he can do. Animated. Backstopped by a stream of data charts, product photos, and even a beautiful image of supernovae... Read more…

By John Russell

HPC Reflections and (Mostly Hopeful) Predictions

December 19, 2018

So much ‘spaghetti’ gets tossed on walls by the technology community (vendors and researchers) to see what sticks that it is often difficult to peer through Read more…

By John Russell

IBM Bets $2B Seeking 1000X AI Hardware Performance Boost

February 7, 2019

For now, AI systems are mostly machine learning-based and “narrow” – powerful as they are by today's standards, they're limited to performing a few, narro Read more…

By Doug Black

The Deep500 – Researchers Tackle an HPC Benchmark for Deep Learning

January 7, 2019

How do you know if an HPC system, particularly a larger-scale system, is well-suited for deep learning workloads? Today, that’s not an easy question to answer Read more…

By John Russell

Intel Confirms 48-Core Cascade Lake-AP for 2019

November 4, 2018

As part of the run-up to SC18, taking place in Dallas next week (Nov. 11-16), Intel is doling out info on its next-gen Cascade Lake family of Xeon processors, specifically the “Advanced Processor” version (Cascade Lake-AP), architected for high-performance computing, artificial intelligence and infrastructure-as-a-service workloads. Read more…

By Tiffany Trader

  • arrow
  • Click Here for More Headlines
  • arrow
Do NOT follow this link or you will be banned from the site!
Share This