Effects of Piston Pre-Heating and Friction Reduction on Cold-Start Charge Preparation for DI Methanol Engine: An In-Cylinder CFD Study Horse Powertrain Limited

Format:

Book

Conference/Event

Author/Creator:

Bovo, Mirko, author.

Contributor:

Mubarak Ali, Mohammed Jaasim

Conference Name:

17th International Conference on Engines and Vehicles (2025-09-14 : Capri, Italy)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2025

Summary:

Methanol is gaining interest as a renewable fuel for Internal Combustion Engine (ICE) applications. A key challenge for this fuel is its low evaporation rate at low temperatures, which makes cold-starts problematic, particularly in cold climate conditions. The first combustion cycles are characterized by a low combustion chamber temperature and high engine friction. In previous work by the authors, a practical approach was presented to pre-heat the pistons and pre-condition the bearings, thereby reducing friction. In this article, in-cylinder Computational Fluid Dynamics (CFD) modeling is used to study the charge preparation of a DI-SI methanol ICE up to the end of compression. The model is calibrated in-house using measurements from a warm methanol engine. The piston temperature is varied within the range expected from the pre-heating and pre-lubricating device. Friction reduction is translated into the reduced amount of fuel needed to generate the IMEP required to idle the engine. Engine starting conditions at -20°C, 0°C, and +20°C are simulated. For these global conditions, different combinations of piston pre-heating and friction reduction are investigated. Warm engine conditions (90°C) are also modeled for comparison.The results show that the piston is a primary target for fuel spray. As expected, for a warm engine, the injected fuel is completely evaporated. For an ordinary cold-start at 20°C, the fuel distribution at the end of compression is 81% evaporated, 15% remains as film, and the rest as suspended droplets. In the cold-start at -20°C, only 23% of the fuel is evaporated at the end of compression, while the majority is deposited as a fuel film. By pre-heating the piston alone, the evaporated fuel increases to 37%. Alternatively, reducing the friction load to match warm engine conditions, drastically reduces the total fuel injected, resulting in 59% evaporated fuel. This demonstrates the potential of the proposed technology to improve methanol cold-start emissions

Notes:

Vendor supplied data

Publisher Number:

2025-24-0040

Access Restriction:

Restricted for use by site license