Welcome to Honda and Acura’s brand new advanced wind tunnel.
This likely comes as no surprise, but designing a brand new vehicle is a costly and labor-intensive process. If you want to build something desirable, something useful — something your customer actually wants — then it’s essential to put in the time and resources necessary to actually deliver a worthwhile product. That’s why we see automakers testing their prototypes all over the world. But even major players like Honda can face a logistical quandary when they have to rent out wind tunnels as part of the process for developing their brand new models. That’s where this advanced wind tunnel comes in — a $124 million project to bring aerodynamics and acoustic testing into a single location.
Honda invited journalists out to what it calls the HALO (Honda Automotive Laboratories of Ohio) facility to catch a glimpse into exactly how that development will happen.
It’s a project five years in the making
Located at the Transportation Research Center Inc. (TRC) facility in East Liberty, Ohio, just down the road from Honda’s own Marysville production plant, this facility first broke ground back in 2017. The idea then was to create a facility that will support North American product development, particularly as the company pivots with the rest of the industry toward electric vehicles.
When the HALO wind tunnel ramps up into full operation in the coming months, it will play a major role in Honda and Acura’s road-going product line, as well as Honda Performance Development (HPD)’s motorsport programs, STEM research activities and eventually other companies’ aerodynamics testing needs.
What sort of testing conditions can the HALO tunnel create?
When you first enter the open test section, you’re greeted by a wide air inlet at one end, with a large collector at the other. In fact, Honda’s wind tunnel uses a variable nozzle area to vary wind speed. In an 18 square meter configuration, engineers can test cars up to 192.63 mph (310 kph). The facility uses a 1/8-mile closed return system — a rectangular layout wherein a series of curved vanes direct the air flow from the 8-meter fan through a heat exchanger before feeding it through the test section. The large radiators allow engineers to maintain a constant air temperature between 10 and 50 degrees Celsius, as part of the process to ensure conditions are as ideal as possible for the sort of real-world conditions they want to simulate.
As for the fan itself:
The General Electric-built unit comprises 12 hollow carbon fiber, fixed-pitch blades attached to a 5-megawatt electric motor. At max speed, the 6,700 horsepower electric fan can spin up to 250 RPM, allowing for that 192 mph wind velocity. While I did get to stand in the air stream while the fan was active (secured to the floor by a harness system), the engineers did not run it anywhere near that speed. Instead, we experienced testing conditions at about 50 kph, or around 31 mph.
Back in the 3-by-5-by-15 meter test section, the wind tunnel engineers also moved out large microphone arrays to show its aeroacoustic testing capabilities. In addition to a 180-degree turntable to face the car into the wind, Honda uses hundreds of strategically-positioned mics to judge wind noise.
In positioning the car on the platform, the engineers use one of two interchangeable 40-ton belt modules to create a rolling road setup, depending on the vehicle and conditions in which they’re testing. A five-belt system (shown with the Acura MDX Type S above) uses a belt under each tire with one belt running under the center. The other ‘wide belt’ system (shown with the Acura TLX Type S below) uses one large belt under the vehicle. The latter module can more easily accommodate high-performance vehicles, as it’s also the one capable of working in tandem with the wind tunnel layout to achieve the maximum testing speeds.
Aeroacoustic testing
While Honda’s teams used to test aerodynamics and aeroacoustics in different locations, the HALO facility allows both to take place in-house. To that end, working out the acoustic side of vehicle development incorporates arrays with 556 distinct microphones and cameras to pinpoint problem areas that customers may detect on the move. The exterior setup uses 502 directional microphones, and engineers place 54 microphones inside the cabin for sound source detection, like bits of wind noise through the A-pillars (or anywhere else in the car).
All this data comes together inside a control room just off the open test section, manned by several technicians under experienced automotive engineer and Honda wind tunnel lead Mike Unger. Honda uses Supervisory Control and Data Acquisition (SCADA) software developed by Cosworth to interpret all the information gathered while performing aerodynamics and aeroacoustic testing, be it during production or racing development.
Opening up the HALO wind tunnel
As I mentioned earlier, it’s not just Honda who may benefit from HALO’s technology, either. Sure, the automaker touts the benefits of its advanced facility for its own EV development — wind noise is a major factor to consider absent internal combustion, where engine and exhaust noise that would normally mask some of it — but it’s open to other parties using the facility as well.
Part of the TRC’s mission is collaborating with research, particularly with Ohio State University students. They will work in the facility, as can other businesses that need to make use of a wind tunnel for their own development. Honda designed the wind tunnel with third parties in mind, and our tour of the building included four secure bays, in which customers can offload vehicles while using roll-down doors to ensure privacy over any critical information. It’s the same story for moving vehicles out into the test chamber — a large vault-style door seals off the area from prying eyes, while the control room area uses key cards to restrict access to those who need it.
In the event a third-party customer does come into the schedule, they will work with outside contractors rather than Honda’s own technicians, and Unger emphasized those parties will keep exclusive control over all their testing and the information it yields.
For the immediate future, though, Honda is largely focused testing its own vehicles. The HALO wind tunnel will support the company’s efforts to improve fuel efficiency over the coming few years, while also developing and refining their range of forthcoming electric vehicles.
Real-world results
Of course, we’ll only experience the team’s efforts in real-world driving, and we just so happen to have a recent video with the Acura NSX Type S. Tommy drove it out in California, and you can check that video out below: