A novel technique for detailed and time-efficient combustion modeling of fumigated dual-fuel internal combustion engines

Abstract

The present work details a study of the 3D-modeling of dual-fuel engines, with a specific focus on medium speed marine engines. These operate under the fumigated approach, which means that the second fuel, which replaces most of the diesel fuel, is added in the intake duct. This type of engine requires the least amount of modifications to the current medium speed diesel engine and is therefore an ideal retrofit solution to tackle global warming and local air quality issues. In this work, the operation of such an engine has been modeled, with special care for the combustion modeling. Namely, it comprises both auto-ignition of the diesel pilot, and flame propagation in the premixed fuel-air mixture. A tabulated kinetics approach, currently being used to model diesel operation, has been extended to include this flame propagation. Both a Coherent Flame Model (CFM) and a Flame Surface Wrinkling Model (FSWM) have been implemented to handle this premixed combustion mode. Coupling a flame propagation model to the tabulated chemistry should provide a practical way of capturing both the complex dual-fuel combustion process as the chemistry information, while maintaining an acceptable computation time. Additionally, a tabulated laminar flame speed method has also been implemented. Experimental results were obtained on the operation of a medium-speed engine in diesel, natural gas/diesel dual-fuel and methanol/diesel dual-fuel mode, under varying operating loads and speeds. Results have been compared to the ones obtained from the simulations performed in OpenFOAM with the dedicated combustion modeling technique. It was found that while both FSWM and CFM capture some physical trends, they are currently not able of capturing the dual-fuel combustion process in total.Improvements with regards to the ignition and mixing-controlled combustion modeling are necessary, since the current approach is not able of fully capturing the dual-fuel phenomena. This work however provides insight in the complex combustion process and serves as a basis for further developments. It can also be used as an initial engine development tool for fast calculation and optimization of dual-fuel operation.

Numerical and experimental investigation of exergy, performance, emissions, combustion characteristics, and cyclic variations of CI engine fueled Karanja oil blended camphor oil and diesel blended camphor oil.

“…The actual compression ratio or effective compression ratio (re) depends on the actual airflow rate to the engine or load acting on the engine and is used to determine the effective operation of the engine. The addition of the camphor oil, either with diesel fuel or Karanja oil, reduces the effect of expansions of the residual gas in the clearance volume by providing combustion turbulence (Decan et al 2020). Hence, an increase in the actual compression ratio is found for C70D30 and C70K30.…”

Studi Eksperimental Performa Satria F 150 Menggunakan Modifikasi Exhaust Manifold Dengan Nozzle

“…Dalam menggunakan sepeda motor perlu disesuaikan kebutuhan yang sesuai dengan spesifikasi dan performa motor. Sehingga pengembangan dan optimalisasi teknologi mesin baru untuk mencapai performa yang baik [3]. Performa motor dapat berubah turun karena usia pemakaian.…”

Towards a Predictive Simulation of Turbulent Combustion?—An Assessment for Large Internal Combustion Engines

“…All mentioned flame regimes may occur, starting with diesel-like combustion that transitions to a lean burn premixed combustion and may, if the knock-limit is reached, result in an auto-ignition of the homogeneous, unburned mixture. In [107] the authors used a combination of coherent flame and surface wrinkling model and declared that in spite of capturing some physical trends, further improvements of the mixing controlled combustion are still needed. Research work was carried out with a special focus on the extended chemistry involved due to the two fuels in [108][109][110].…”