Just a few months into a joint innovation project, experts from Bosch Engineering and Ligier Automotive have built a high-performance vehicle with a hydrogen engine. The demonstrator is based on the Ligier JS2 R race car, which was modified for hydrogen operation. With this innovation vehicle, both companies demonstrate the potential that alternative, climate-friendly drive systems have for high-performance applications such as motorsports. The Ligier JS2 RH2 was officially presented to the public for the first time today as part of the 100th anniversary of the 24 Hours of Le Mans. “Hydrogen engines offer a huge potential for high-performance applications, especially in motorsports. By constructing the demonstration vehicle, we illustrate our many years of expertise as an engineering service provider and, in particular, our competence in the complex environment of hydrogen”, says Dr. Johannes-Jörg Rüger, president of Bosch Engineering GmbH. Jacques Nicolet, president of Ligier Automotive adds, “The Ligier JS2 RH2 shows that Bosch Engineering and Ligier Automotive are ready to tackle tomorrow’s challenges by offering innovative solutions to integrate new energies.” The Ligier JS2 RH2 has already been driven on test tracks in Germany and will be further developed and tested during the summer.
In the project, Bosch Engineering oversaw the overall vehicle design and played the key role in developing the concept for engine and tank system, and a comprehensive multistage hydrogen safety system. Ligier Automotive was responsible for the global vehicle dynamic performance, the design of the monocoque, and the chassis adaptation of its existing Ligier JS2 R. They also optimised the mechanical components for use with hydrogen and led their overall integration into the new vehicle. The vehicle features a V6 hydrogen engine and a carbon monocoque that integrates three 700-bar type IV hydrogen cylinders from Hexagon Purus. These tanks match the requirements on the dimensions, performance, and safety for the high-performance demonstration vehicle. The 3.0-liter biturbo charged V6 engine already has an output of 420 kilowatts and will be optimised even further in the coming weeks. It is based on a volume-production gasoline power unit that the experts at Bosch Engineering have converted for use with hydrogen. In particular, this involved adapting the ignition and the entire injection system. Not only does the engine concept ensure very lean combustion, with especially low nitrogen oxide emissions up to partial load. It also delivers a very high specific output. Another challenge while developing the engine was to achieve stable combustion without preignition at high loads and engine speeds of over 7,000 rpm.
The vehicle’s multistage hydrogen safety concept includes the storage system with its high-pressure tanks as well as the pressure controllers and supply lines to the engine and injection system. For example, integrating Hexagon Purus hydrogen tanks into the vehicle’s carbon monocoque ensures optimised packaging and a high level of safety in the event of a crash. Separation of tank, gas control components and engine compartments plus a passive ventilation concept through pipes and chimneys ensure that gases are specifically removed to the outside in a failure situation and avoid entering the passenger compartment or closing to hot parts from engine bay. In addition, leaks in the system are detected by an extensive sensor system. Rüger explains, “Depending on the type and severity of the defect, the system triggers a multistage active safety concept, ranging from a warning to the driver on the display to a shutdown of individual line circuits up to an entire system shutdown.”
Adapting the Ligier JS2 R to integrate the hydrogen system was key to the project’s success. “We decided to replace the existing structure with a carbon monocoque and worked closely with our sister company HP Composites and the R&D specialist Carbon Mind on this aspect of the project,” explains Julien Jehanne, plant manager at Ligier Automotive. “We have relied on all our experience as a racing car constructor and created a custom-made carbon monocoque. With our current Ligier range of cars and the expertise we have developed in the past years, we have all the tools to design and build reliable high-performance cars integrating new energies.”
Bosch Engineering has already been working on concepts for hydrogen engines since 2016 and provides services for high-performance applications, as well as for other areas. Not only does Bosch Engineering benefit from its many years of experience as a development partner for super sports cars and motorsports. It also has extensive specific expertise in dealing with hydrogen. For the development and application of hydrogen drives – both as internal-combustion engines and with fuel cells – there are specially equipped test benches operated by certified, trained personnel, a hydrogen filling station, and workshops with all the necessary ventilation technology.