Simulation Of Combustion Characteristics Research Articles

The Simulation of Combustion Characteristics from Diesel Fuel and Biodiesel in Different Engine Rotation

The combustion characteristics of fuel are important to understand. Diesel engines can ruin by using fuel from diesel and biodiesel. The characteristics between biodiesel and diesel fuel are different. Diesel fuel has low viscosity, high volatility, low density, and cetane number is around 48. However, biodiesel has high density, low volatile, high viscosity and has higher cetane number than diesel fuel. Using biodiesel can reduce the particulate matter from the engine. This happened because biodiesel has high oxygen content and can reduce emissions. These are some advantages of using biodiesel in diesel engines. In this research, the simulation of the combustion characteristics were investigated by diesel-rk simulation. The fuels are diesel fuel and biodiesel made from soybean methyl ester (SME). In this simulation, pure diesel fuel (DF), SME100, SME20 (20%SME blends to 80%DF) and SME40 (40%SME blends to 60%DF) are investigated. The combustion was set up with 1500, 1800, and 2000 rpm. The results show that in all engine rotations, DF has higher Specific Fuel Consumption (SFC) than SME. Moreover, the NO2 emission from DF is lower than SME. However, the particulate matter in SME40 can reduce up to 16.1% compared to DF. Moreover, the higher the engine rotates, the emissions from NO2 and PM from SME20, SME40, and DF can be reduced. It can be confirmed that the higher rotation in the engine can decrease the emissions in the engine. In addition, biodiesel can be replaced with diesel fuel and it is environmentally friendly.

Large Eddy Simulation of Combustion Characteristics of Non-premixed Methane Jet with Pilot Diesel in High-Pressure Direct Injection Mode

Large Eddy Simulation of Combustion Characteristics of Non-premixed Methane Jet with Pilot Diesel in High-Pressure Direct Injection Mode

Numerical simulation of combustion characteristics and emission predictions of methane-air and hydrogen-air mixtures in a constant volume combustion chamber using multi-point laser-induced spark ignition

ABSTRACT Lean-burn combustion using higher spark energy can enhance the combustion characteristics and emission performance. A laser is electrodeless with a high energy ignition source and can achieve multi-point ignition easily. This paper presents the computational fluid dynamics (CFD) modeling of combustion of methane-air and hydrogen-air mixture in a constant volume combustion chamber (CVCC) by using multi-point laser-induced spark ignition (LISI). The numerical simulation is carried out using ANSYS Fluent software, and a standard turbulence model (k – ε) is used. The pressure-time history and reaction progress was plotted for various equivalence ratios (ϕ). Numerical result shows that multi-point ignition can completely burn methane-air and hydrogen-air mixture in the range of 0.77 to 1.68 and 0.36 to 4.1, respectively. The maximum peak pressure (Pmax) and shortest combustion duration were observed at ϕ of 1.29 for the methane-air mixture and ϕ of 1.0 for the hydrogen-air mixture. The relative error between the numerical and the experimental results from the literature are within 10%. The faster reaction progress was observed for the hydrogen-air mixture compared to the methane-air mixture for all equivalence ratios. Finally, the validated numerical model was used to predict the CO, CO2, and NOx emission trends. For the methane-air mixture, CO emission increases as the equivalence ratio increases. However, the maximum CO2 emissions were observed at stoichiometric conditions. The highest NOx emissions were observed for the hydrogen-air mixture compared to the methane-air mixture at a stoichiometric equivalence ratio.

Simulation of combustion characteristics in a hydrogen fuelled lean single-element direct injection combustor

Combustion characteristics in a hydrogen fuelled single-element lean direct injection (LDI) combustor for low emission gas turbine engine are computationally investigated. A single-element LDI combustor was produced and simulated with steady-state Reynolds-averaged Navier–Stokes reacting computations. Reacting computations of the single-element LDI combustor were performed with an augmented reduced 23-step reaction mechanism for hydrogen/air. A realizable k − ε model was used to obtain turbulence closure. For the single-element LDI combustor with different equivalence ratio, the effective area, axial velocity, total pressure drop coefficient, total temperature, mass fraction of OH, emission index of pollutant NO (EINO) were achieved and discussed.

A Review Paper on Simulation and Modeling of Combustion Characteristics under High Ambient and High Injection of Biodiesel Combustion

This paper describes simulation of combustion characteristics under high ambient and high injection of biodiesel combustion by using CFD simulation. Diesel engine performance and emissions is strongly couple with fuel atomization and spray processes, which in turn are strongly influenced by injector flow dynamics. The principal objective of this research is to seek the effect of temperature and pressure on the spray characteristics, as well as fuel-air mixing characteristics. Experiments were performed in a constant volume chamber at specified ambient gas temperature and pressure. This research was continued with injecting diesel fuel into the chamber using a Bosch common rail system. Direct photography technique with a digital camera was used to clarify the real images of spray pattern, liquid length and vapor penetration. The method of the simulation of real phenomenon of diesel combustion with optical access rapid compression machine is also reviewed and experimental results are presented. The liquid phase of the spray reaches a maximum penetration distance soon after the start of injection, while the vapor phase of the spray continues to penetrate downstream. The condition to which the fuel is affected was estimated by combining information on the block temperature, ambient temperature and photographs of the spray. The increases in ambient pressure inside the chamber resulting in gain of spray area and wider spray angle. Thus predominantly promotes for a better fuel-air mixing. All of the experiments will be conducted and run by using CFD. The simulation will show in the form of images.

Numerical simulation of combustion characteristics at different coal concentrations in bituminous coal ignition in a tiny-oil ignition burner

With the objective of producing a full-scale tiny-oil ignition burner, identical to the burner used in an 800 MWe utility boiler, numerical simulations were performed using Fluent 6.3.26 to study the progress of ignition for four coal concentration settings covering sub-operation conditions prevailing during the experiments performed with the burner. The numerical simulations conformed to the experimental results, demonstrating the suitability of the model used in the calculations. Simulations for a coal concentration of 0.40 kg/kg corresponding to a single burner operating at its rated output were also conducted, which indicated that gas temperatures along the burner centerline were high. As gas flowed to the burner nozzle, the high-temperature region expanded, ensuring a successful pulverized-coal ignition. With increasing coal concentration (0.08–0.40 kg/kg), the gas temperature along the burner centerline and at the first and second combustion chamber exits decreased at the equivalent radial points. At the center of the second combustion chamber exit, the O2 concentrations were almost depleted for the five coal concentrations, while the CO concentrations peaked.