A GLOBAL LEADER IN THE FIELD OF AERODYNAMICS, LEXUS UNVEILS A NEW,WORLD-CLASS LABORATORY AND ITS BREATHTAKING WIND TUNNEL.
The first thing that strikes you about the Lexus aerodynamic laboratory is its size. Situated at the company’s research and development headquarters in Japan’s Aichi Prefecture, the lab’s custom-built wind tunnel is a cavernous, 22-meter-high, 260-meter-long loop. If it were stretched out and tipped on its end, it would be as tall as many of Tokyo’s highest skyscrapers.
The laboratory’s opening in March 2013 was a significant moment in Lexus’s history. It pitches the firm as a global automotive leader in the field of aerodynamics – the science of how airflow affects a car’s noise levels, dynamic characteristics and environmental specifications.
“For the past three decades we have paid considerable attention to automotive aerodynamics. We’ve always considered it one of the most important parameters to investigate when developing new models,” says Toshiyuki Murayama, group manager of thermal management and aerodynamics at Lexus.
In the wind tunnel, Lexus engineers analyze the airflow around a vehicle’s wheel, tail, bumper and undercarriage. “The most important function is to generate a very steady flow of air towards the car so we can understand precisely how air travels around it,” says Murayama. To maintain this airflow, the tunnel’s continuous loop is punctuated by metal slates slanted at a precise angle to guide the air through smoothly. “We had experts come in to fine-tune all the structural details such as the layout of walls, the selection of materials and the location of vents and nozzles, to make this lab one of the most reliable research facilities in the world,” says Murayama.
All this effort and attention to detail shows just how important the field of aerodynamics has become. How the air flows around a vehicle is key to measuring the drag and down force – and the less drag there is, the more fuel-efficient and better-performing the car. “When a car is cruising at 60mph, air drags account for as much as 70 percent of the forces affecting driving performance. Even at lower speeds, when driving in the city, a better aerodynamic system can improve both fuel efficiency and road stability,” says Murayama.
To professional racing drivers, it can be the difference between victory or failure on the circuit.
Building the laboratory so close to thev design headquarters was a strategic decision: it allows Lexus car designers to work closely with engineers and test models as they’re being made. “We have had other aerodynamic facilities but this one sets itself apart. Design and aerodynamics have so much in common. Even a tiny exterior part of the car can change the flow of air around the body of a car – for better or for worse – so it is key that one of our most advanced laboratories is just a stone’s throw away from the design division,” says Murayama.
So what goes on inside the lab? First, the car is wheeled onto a turntable weighing scale in the central testing room.
TODAY, THIS LABAROTORY IS ONE OF THE MOST RELIABLE RESEARCH FACILITIES IN THE WORLD.
“Weight distribution to each of the four wheels changes depending on how the wind travels around the car, affecting its aerodynamics, so we closely monitor that too,” explains Murayama. The turntable also acts as a treadmill, with five belts (four for each wheel and one in the centre) allowing the car to reach top speeds without moving an inch. A thick, fast-moving stream of smoke is released to reveal how air travels around the car. Next the wind turbine is put into action, unleashing winds that can reach hurricane speeds of up to 250kmph. All the while, a team of engineers monitors every tiny aspect of the car’s behavior, tweaking, reacting, adjusting and fine-tuning at the same time.
Consumers are increasingly concerned about wind noise – another area in which Lexus excels. The surfaces of the wind tunnel are covered with sound-absorbing material, so the only thing the engineers can hear is the turbulent noise caused by wind going over, under and around the car. The level of detail that goes into noise-testing is astonishing. Whereas the human ear can only detect sounds of 20Hz and above, the walls reduce any noise and pulse pressure to 1Hz or less.
“It can be so quiet, you wouldn’t even notice if the wind tunnel is active if you couldn’t see the car in place for testing,” says Murayama with a laugh. “We have an array of microphones on the ceiling and walls that helps us visualize noises on the computer screens.”
One of the latest production models to get the full benefit of the laboratory is the Lexus RC F high performance coupe. Its chief engineer, Yukihiko Yaguchi, proudly describes the car as “honed to perfection in the wind tunnel”.
By simulating road conditions at the laboratory, Lexus can get immediate feedback in the development of its cars without having to leave the premises. And innovative prototype parts, such as small stabilizer fins made with on-site 3D printers, can be quickly and easily put to the test.
Before he gets back to work Yaguchi says, “Every part of the car is designed in the margin of a millimeter. We go through every possible layout of the ducts or the sizing of the aerodynamic parts. All the details and conditions must be taken into consideration so that each car can cope with any kind of road or any kind of weather condition. It’s no easy job.”
It might not be the easy route, but Lexus’s meticulous approach is paying off. The new wind tunnel will help the firm design the world’s most aerodynamically sophisticated cars that will, in turn, shape the future of the automotive industry.