scholarly journals Analysis of rotary engine combustion processes based on unsteady, three-dimensional computations

1990 ◽  
Author(s):  
M. RAJU ◽  
E. WILLIS
Keyword(s):  
Three Dimensional ◽  
Rotary Engine ◽  
Engine Combustion ◽  
Combustion Processes

Three-dimensional simulation analysis of the effect of hydrous ethanol and exhaust gas recirculation on gasoline direct injection engine combustion and emissions

2021 ◽  
pp. 1-22
Author(s):  
Xiuyong Shi ◽  
Yixiao Jiang ◽  
Qiwei Wang ◽  
Weiwei Qian ◽  
Rong Huang ◽  
...  
Keyword(s):  
Aqueous Ethanol ◽  
Direct Injection ◽  
Three Dimensional ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Engine Combustion ◽  
Carbon Soot ◽  
Dimensional Simulation ◽  
Gas Recirculation ◽  
Hydrous Ethanol

Abstract To analyze the influence of hydrous ethanol on the performance of the direct injection engine, the three-dimensional simulation is carried out by using CONVERGE software coupled with the combustion mechanism of hydrous ethanol gasoline and the soot model. The combustion and soot generation characteristics of a direct injection gasoline engine burning aqueous ethanol gasoline using exhaust gas recirculation (EGR) technology were investigated. It was found that the increase of the blending ratio of the hydrous ethanol can accelerate the flame propagation speed, shorten the combustion duration, and improve the combustion isovolume. The nucleation and growth of soot are jointly controlled by PAHs and the small molecular components such as C2H2. The oxygen content properties and high reactive OH of the aqueous ethanol-containing gasoline inhibit soot formation. Compared with pure gasoline, the carbon soot precursor mass was reduced by 60%, 54.5%, 73.3% and 52.4% for 20% anhydrous ethanol blended with gasoline, A1, A2, A3 and A4, respectively, and the carbon soot mass was reduced by 63.6% and the carbon soot volume density was reduced by 40%. The introduction of EGR exhaust reduces the burning rate and leads to an increase in the production of Carbon monoxide, hydrocarbon, and soot. However, the combination of EGR with aqueous ethanol gasoline can significantly improve the engine combustion environment, significantly reducing soot and PAHs concentrations. The impact of EGR also includes the ability to reduce combustion chamber temperatures and reduce NOx emissions from aqueous ethanol gasoline by 75%.

Simulation of Pollutant Emissions in a Small-Sized Combustion Chamber With a Gas Fuel for Various Regime Modes

2019 ◽  
Author(s):  
Nikita I. Gurakov ◽  
Ivan A. Zubrilin ◽  
Ivan V. Chechet ◽  
Vladislav M. Anisimov ◽  
Sergey S. Matveev ◽  
...  
Keyword(s):  
Experimental Data ◽  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Combustion Products ◽  
Pollutant Emissions ◽  
Eddy Simulation ◽  
Flamelet Generated Manifold ◽  
Combustion Processes

Abstract The study shows the results of the emission simulation in a small-sized combustion chamber. The influence of temperature and equivalence ratio on CO and CxHy in the combustion chamber was investigated. Experiments and calculations were carried out for the following modes: temperature at the inlet of the combustion chamber Tinlet = 323 ... 523 K; equivalence ratio φ = 0.2 ... 0.33; normalized flow rate at the inlet of the combustion chamber λ = 0.1 ... 0.3. The simulation of combustion of natural gas was carried out. The studies were conducted using CFD software and experimental methods. Measurements of the combustion products composition were carried out by the method of sampling collection and subsequent chromatographic analysis. The flow and combustion processes were simulated in a three-dimensional steady formulation using the Reynolds-averaged Novier-Stokes equations (RANS) and in a transient formulation using the Large Eddy Simulation (LES) method. The combustion processes were simulated by Flamelet Generated Manifold model in conjunction with the probability density function method (PDF). In addition to the above methods, the method of the reactor network model (RNM) was used to simulate the emission. As a result, a comparison of the calculated and experimental data of concentrations values of combustion products and emissions indices averaged over the combustion chamber outlet was conducted. According to the results of the calculated-experimental study obtained: - the simulated concentrations values of the main combustion products such as CO2 and H2O qualitatively and quantitatively coincide with the experimental data (the discrepancy is less than 5%) for all three approaches — RANS, LES, RNM; - when modeling CO emissions, the discrepancy between the calculated emission indices obtained by the RANS and LES methods is greatly underestimated relative to the experimental data, whereas the values calculated by the RNM method deviate from the experiment by less than 10%; - mass concentration values of unburned hydrocarbons obtained by the RANS method are overestimated relative to the experimental values, while using the LES with RNM methods, the discrepancy does not exceed 10%.

Systematic Uncertainty Considerations in the Comparison of Experimental and Computed Cylinder Pressure and Heat Release Histories

2018 ◽  
Author(s):  
K. R. Partridge ◽  
P. R. Jha ◽  
H. Mahabadipour ◽  
K. K. Srinivasan ◽  
S. R. Krishnan
Keyword(s):  
Heat Release ◽  
Cylinder Pressure ◽  
Computational Simulations ◽  
Cfd Simulations ◽  
Engine Combustion ◽  
Computational Fluid Dynamics Cfd ◽  
Ic Engines ◽  
Dynamics Simulations ◽  
Combustion Processes ◽  
Experimental Pressure

Computational simulations of engine combustion processes are increasingly relied upon to lead the design of advanced IC engines. Both computational fluid dynamics (CFD) simulations as well as thermodynamics-based phenomenological 0D or 1D gas dynamics simulations are examples of current simulation strategies. Before simulations can be utilized to guide the design process, they must be validated with experimental results. Typically, the experimental data used for validation of computational simulations include in-cylinder pressure and apparent heat release rate (AHRR) histories. However, the process of comparison of experimental and simulated pressure and AHRR curves is largely qualitative; therefore, the validation process is mostly visual. In the present work, the authors introduce a framework for quantifying uncertainties in experimental pressure data, as well as uncertainties in the “average” AHRR curve that is derived from ensemble-averaged cylinder pressure histories. Predicted AHRR curves from CFD simulations are also quantitatively compared with the experimental AHRR bounded by “uncertainty bands” in the present work.

Simulation Study on Different Composition Fuels in Lean-Burn CNG Engine

2013 ◽  
Vol 448-453 ◽  
pp. 3430-3433
Author(s):  
Chang Qing Song ◽  
Jun Li ◽  
Da Wei Qu ◽  
Qi Jie Liu
Keyword(s):  
Three Dimensional ◽  
Hydrocarbon Fuel ◽  
Simulation Software ◽  
Combustion Model ◽  
Lean Burn ◽  
Maximum Heat ◽  
Cng Engine ◽  
Valve Opening ◽  
Dimensional Simulation ◽  
Combustion Processes

The Paper has Established a Combustion Model of Lean-Burn CNG Engine by Three-Dimensional Simulation Software AVL FRIE. Based on Test Validation in the Model, the Combustion Processes of Seven CNG Samples were Simulated and Compared from the Intake Valve Closed to the Exhaust Valve Opening. the Effects on Different Composition Fuels for CNG Engine were Researched. the Results Showed that: the Maximum Average Pressure within the Cylinder , the Highest Average Temperature, the Maximum Heat Release Rate, the Initial Mass Fraction of Fuels, CO and NO Formation Increased with the Hydrocarbon Fuel Ratio C/H, the Composition of Heavy Paraffin in CNG Directly Affected the Performance and Service Life of the Engine.

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