Research into climate-friendly large-scale engines for maritime applications is being further expanded at the Technical University of Munich (TUM). The IBFlex project is establishing a modern research infrastructure that enables the investigation of alternative fuels such as ammonia and methanol under engine-relevant conditions. The objective is to experimentally analyze novel combustion concepts and accelerate the development of low-emission dual-fuel engines for maritime applications.

At the core of the project is the further development of an existing Rapid Compression Expansion Machine (RCEM) at the Chair of Sustainable Future Mobility (SFM). The research activities focus on two main areas:

1. Expansion of the RCEM for Flexible Combustion Concepts

The existing RCEM is being upgraded from a diffusive combustion process, similar to High-Pressure Direct Injection (HPDI), to a homogeneous combustion process comparable to Port Fuel Injection (PFI). This will allow different injection and combustion strategies using ammonia and methanol to be investigated under comparable operating conditions.

In addition, the existing FTIR measurement system is being enhanced. New modules will enable oxygen measurements as well as ammonia burnout analysis. The upgraded infrastructure therefore provides the basis for detailed investigations into the ignition behavior of diesel or future biodiesel pilot fuels in alternative fuel-air mixtures.

2. Improvement of Optical Diagnostics and Spray Analysis

Another major focus lies in the modernization of the optical diagnostic systems. Additional optical access points in the cylinder head will improve existing measurement techniques such as OH* chemiluminescence, shadowgraph imaging, and Mie scattering.

Furthermore, a new methanol injector and a Particle Image Velocimetry (PIV) system will be acquired. These additions will enable highly time-resolved investigations of injection and spray development processes for both homogeneous and diffusive combustion concepts.

With IBFlex, TUM builds upon the successful predecessor projects AmmoniaMot and FlexDi, further strengthening its role in the development of climate-friendly combustion technologies. The project therefore contributes significantly to the decarbonization of maritime transport and to Germany’s technological leadership in sustainable marine propulsion systems.