[Report] Alps Mountains, Middle Eastern Deserts... The Secret Behind Domestic Hydrogen Trucks Running Smoothly

Hyundai Motor Namyang Research Center Unveils World's Only Commercial Environmental Wind Tunnel
Simulates Real Driving Conditions in Extreme Cold and Heat
Refines High-Performance Electrification Technology and Internalizes Battery Technology

Buses and trucks travel much more frequently than passenger cars. The average daily driving distance for non-commercial passenger cars is about 31 km, which amounts to approximately 11,000 km per year. The average daily driving distance for commercial passenger vehicles like buses is 145 km, nearly 53,000 km annually.

The annual driving distance for trucks and other freight vehicles is 48,000 km, while special vehicles used for towing and rescue approach an average of 57,000 km. It is not uncommon for buses and trucks to exceed 1 million km in mileage. Moreover, they often operate not only in urban areas but also on rough terrain. This is why durability is considered more important than for passenger cars.

A flow visualization test is being conducted at Hyundai Motor Group Namyang Technical Research Center's commercial environment wind tunnel. To enhance the vehicle's aerodynamic performance, gas is injected inside the wind tunnel to observe the airflow around the vehicle.
[Photo by Hyundai Motor Group]

At Namyang Technology Research Center, known as Hyundai Motor Group’s R&D hub, there is a commercial environment wind tunnel facility that plays a crucial role in the development process of commercial vehicles. It is a facility uniquely owned by Hyundai Motor Group worldwide.

While there are many wind tunnel test facilities for general passenger cars or internal combustion engine commercial vehicles, none have yet equipped facilities considering eco-friendly commercial vehicles. Hyundai produces various electric bus models, including double-decker buses and articulated buses measuring up to 18 meters in length. Hyundai is also the only company mass-producing large trucks powered by hydrogen fuel cells.

Lee Kang-woong, Chief Researcher of Hyundai Motor Group’s Commercial Fuel Efficiency and Driving Performance Testing Team, explained, "This is the world’s first commercial vehicle wind tunnel facility equipped with a system capable of developing all types of vehicles. All facilities in the test room, including lighting and wiring, meet safety standards strong enough to withstand hydrogen explosions."

Hyundai Xcient hydrogen electric trucks being loaded onto a European export vessel in 2020
[Photo by Hyundai Motor Group]

On the 27th, inside the test room visited by domestic and international media, a large hydrogen fuel cell truck, the Xcient, was running on a dynamometer (motor test power meter). Since commercial vehicles mostly have rear-wheel drive to carry cargo, the front wheels were fixed with special equipment made by the US company BEP. The rear part of the vehicle was also secured with large chains.

On that day, the interior of the test room was set to 45 degrees Celsius, the test standard temperature for the Middle East region, making it quite humid and warm. Lighting was installed on the ceiling and sides to emit light similar to actual sunlight. The interior temperature of the vehicle, heated by the light, reportedly exceeded 60 degrees Celsius. Such testing is mandatory for vehicles sold in the US market.

Hyundai Motor Namyang Research Center Commercial Wind Tunnel Testing Room. The light from various illuminations produces effects similar to sunlight. [Photo by Hyundai Motor Group]

The test room can conduct all performance tests related to real vehicle driving, including cooling and heat resistance, fuel efficiency, cold start, heater and air conditioning, charging and discharging, power, mode driving, and exhaust certification. Temperature can be controlled from minus 40 degrees to 60 degrees Celsius, and humidity from 5% to 95%. Airflow up to 120 km/h is generated in front of the vehicle to simulate actual driving conditions.

This simulates various environments to develop vehicles capable of driving in cold Siberian winters or Middle Eastern deserts. The hydrogen truck, the world’s first mass-produced model by Hyundai, has been running on Swiss roads with many high-altitude areas since 2022. It has also been exported or is planned to be exported to the western United States and Saudi Arabia.

This test room is also useful for developing commercial electric vehicles. Since battery efficiency varies with temperature, various performance aspects such as charging and discharging can be examined. It is possible to check how charging efficiency changes in cold or hot conditions.

Hyundai is also discussing with the Korea Energy Agency the use of this facility for hydrogen truck fuel efficiency measurement methods, which currently lack clear regulations. The company said they are discussing a method using weight measurement with hydrogen supply equipment connected from the ceiling.

A robot inside the vehicle is controlling acceleration and deceleration in the electric vehicle powertrain test lab.
[Photo by Hyundai Motor Group]

In another part of the Namyang Research Center, the electric vehicle dynamometer test room is used to develop and evaluate the basic performance of motors and inverters directly related to the driving performance of electrified vehicles. This facility was established within the Electrification Test Center, created by reorganizing the existing powertrain development organization into an electrification organization.

Harsh tests are repeatedly conducted. It is possible to simulate various situations in a compressed timeframe compared to real road driving tests. When problems arise, causes can be identified and fixed more quickly. Kwak Ho-cheol, Chief Researcher of the Electrified Drive Test Team 3, explained, "We conduct comprehensive evaluations from motor component tests to vehicle mass production, dividing tests into 1-axis, 2-axis, and 4-axis depending on the number of dynamometer equipment."

The 1-axis test focuses on motor system performance development at the early development stage. The 2-axis test room adds a reducer and drive shaft to the motor and inverter for testing. It evaluates the overall efficiency of the drive system, mapping, and cooling. It produces results on the effects of heat generation and how to manage cooling performance.

Hyundai Motor researchers are measuring noise during bus braking in the dynamometer anechoic chamber of the Commercial System Test Building.
[Photo by Hyundai Motor Group]

The 4-axis test room houses an actual vehicle to evaluate the entire drive system. It uses the actual battery employed in the vehicle. In addition to various tests, certification-related tests such as electric efficiency evaluation are conducted. Research is also carried out here to minimize load reduction phenomena that control output to prevent electric motors from overheating, and to analyze the development direction of drive systems by testing competitor vehicles.

The diverse data obtained here is shared with departments related to electric vehicle design and development. They check whether the performance meets the intended design and identify reasons for any deficiencies. Conversely, based on test results, they also plan new car concepts and technology strategies for future development.

This test room played a key role in Hyundai Motor Group’s rise to a global top-tier level in the high-performance electric vehicle sector. High-performance electric vehicles must consider driving under harsh conditions. The facility can simulate extreme load conditions, including ultra-high-speed tests running at the Ioniq 5 N’s top speed of 260 km/h. According to a test room official, they are currently developing next-generation high-performance electric vehicles.

Dry room view of the battery analysis lab. Battery materials are sensitive to moisture, so the testing room is kept in a dry condition.
[Photo by Hyundai Motor Group]

In addition, the Battery Analysis Room of the Basic Materials Research Center and the Commercial System Test Building, which conducts over 300 types of tests, were also opened to the media that day. The Battery Analysis Room disassembles basic unit cells to analyze their structure and is a facility to realize Hyundai Motor Group’s battery internalization efforts. It is analyzing new materials to be applied to next-generation batteries developed in-house by Hyundai and Kia.

A company official said, "In the electric vehicle era, the entry barrier has lowered compared to internal combustion engine vehicles, leading to a surge of Chinese automakers entering the market, intensifying competition. In a situation where technology has become standardized, we are continuing a bold R&D journey to secure greater product competitiveness from small differences."