A Study on the Numerical Prediction of Heat Release Rate and NOx Production in Medium-Speed Marine Diesel Engines

Abstract

Prediction of the ROHR (rate of heat release) and NOx production in medium-speed marine diesel engines was investigated. The subject of this paper is qualitative and quantitative evaluation of the numerical results. FIRE code v8.1 was used to examine the behavior of spray and combustion phenomena in diesel engine. Wave breakup and Zeldovich models were adopted to describe the atomization characteristics and NOx formation. The spray visualization was performed experimentally in the constant-volume high-pressure chamber to clarify numerical results on the spray characteristics of the spray angle and penetration. Time-resolved spray behaviors were captured by high-speed digital camera. The simulation results were tested with the experimental data of the real engine. Finally, with adjustment of some model constants, reasonable agreements between experimental and simulated results on the ROHR and NOx were shown.

DE3-3: Optimization of Piston Bowl Shape, Fuel Injection Nozzle and Fuel Injection Rate for the Reduction of NO_x Emissions in a Medium-speed Diesel Engine(DE: Diesel Engine Combustion,General Session Papers)

“…In particular, droplet breakup and droplet drag effects govern the penetration and mixing of vaporizing sprays [1]. gaps between the predictions and measurements, the predicted cylinder pressure and NOx cmissions show good agreement with experiments and those results make it reasonable to attempt prediction of NOxemissions [2].…”

“…The Japan Society of Mechanical Engineers NII-Electronic Library Service in Table 1. The detailed experiment results on the spray angle, spray tip penetration and fuel iajection rate were reported in Kim et aL [2]. Spray angle correlation adopted here is based on the aerodynamic-based model [3] ELnd in this approach, the spray angle, e, is expressed as:…”

Optimization of Fuel Injection Nozzles for the Reduction of NOx Emissions in Medium-speed Marine Diesel Engines(Diesel Engines, Performance and Emissions, NOx Strategies)

“…The cletailed experimental results on the spray angle, spray tip penetration and fuel iniection rate were reported in Kim et aL [1].…”

“…1 and the specifications are listed in Table 1, Target engine is Hyundai HiMSEN H21f32 engine and the engine specifications are shown in Table 2. The spray chamber and optical system were designed to visualize the interrnittent fuel sprays [1].…”

“…In this study, the model constant Ci was set to a fixed value of O.61. But, C2 is tuned to fit the experimental data [1]. (12) was adjusted to 10 for matching the experimental result at 100% load.…”