Bosch Engineering and Ligier Automotive present Ligier JS2 RH2 with hydrogen engine at Le Mans

Jun 01, 2023

Just a few months into a joint innovation project (earlier post), engineers 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.

The Ligier JS2 RH2 was officially presented to the public for the first time as part of the 100th anniversary of the 24 Hours of Le Mans. 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. Ligier also optimized 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 kW and will be optimized 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 more than 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 optimized 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.

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. 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 been working on concepts for hydrogen engines since 2016 and provides services for high-performance applications, as well as for other areas.

Posted on 09 June 2023 in Engines, Hydrogen, Market Background, Motorsport | Permalink | Comments (0)