Computational science is paramount to the understanding of underlying processes in internal combustion engines of the future that will utilize non-petroleum-based alternative fuels, including carbon-neutral biofuels, and burn in new combustion regimes that will attain high efficiency while minimizing emissions of particulates and nitrogen oxides. Next-generation engines will likely operate at h...

Experiments have been carried out with extremely lean, quiescent propane-air mixtures to examine the behavior of irregular flame propagation and to examine the lean limits of flame propagation in a tube under microgravity. The microgravity technique achieved in a freely falling chamber is employed because the realizations of symmetrical flame propagations in a tube are possible. Experimental co...

Three-dimensional (3D) measurements are highly desirable both for fundamental combustion research and practical monitoring and control of combustion systems. This work discusses a 3D diagnostic based on tomographic chemiluminescence (TC) to address this measurement need. The major contributions of this work are threefold. First, a hybrid algorithm is developed to solve the 3D TC problem. The al...

This paper describes an analysis of acoustic wave scattering by turbulent premixed flames with moving, convoluted fronts that have random and possibly fractal characteristics. Such interactions play a role in the characteristic unsteadiness observed in turbulent combustion processes. The problem is posed with an integral formulation of the wave equation and assumes that the smallest scales of f...

An experimental study of the interaction of a planar diffusion flame with a line vortex is presented. A planar diffusion flame is established between two coflowing, equal velocity streams of acetylene diluted with nitrogen and air. A line vortex is generated on demand by momentarily pulsing one of the flow streams by way of electromagnetic actuation of a piston in the flow apparatus. The flame–...

A detailed chemistry-based CFD model was developed to simulate the diesel spray combustion and emission process. A reaction mechanism of n-heptane is coupled with a reduced NOx mechanism to simulate diesel fuel oxidation and NOx formation. The soot emission process is simulated by a phenomenological soot model that uses a competing formation and oxidation rate formulation. The model is applied ...

nowadays, utilization of blended fuel in internal combustion engine is one of main topics in vehicle industries. the synergy effect will be highlighted when the potential of each fuel is employed and the engine performance will improve consequently.  in this research, the laminar flame speed of methane (main component of reference fuel for natural gas) and isooctane (main component of reference...

Study of gas fuel temperature influence on combustion performance by means of numerical modeling is a main objective of this work. Combustion of a single jet of propane in a cross-flowing stream of preheated and oxygen deficient air is analyzed. Both Eddy-Break-Up and PDF/mixture fraction combustion models coupled with RNG k-ε turbulent model were applied and compared. Thermal and prompt NOx mo...

In this paper some results concerning the effect of intake flow modeling obtained by 3D numerical modeling of combustion on flame front shape and its displacement through combustion chamber geometry of s.i .engine consisting of flat head with two ver tical valves and cylindrical bowl were presented. These results obtained with KIVA3V code were compared with results of flame front shape and its ...