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In this paper, computational fluid dynamics (CFD) were employed to a qualitatively and quantitatively study in the behavior of the cold flow in a turbocharged three cylinder spark ignition engine. Dynamic flow experimental characterization was made for low and high engine rotation. One-dimensional modeling software GT-Power was used to calculate the flow pattern generated within the engine cylinder and the results were used as boundary and initialization condition in the CFD model. From the results of the commercial code, volumetric efficiency, in-cylinder pressure and mass are calculated for evaluating the flow development through the four engine strokes, during 4 complete cycles. The CFD model was used as a less expensive alternative to make a deeper study of the flow field.

The use of torch ignition systems in spark-ignition engines represents an interesting option in the efforts to reduce pollutants emission and specific fuel consumption. Based on this idea, this paper presents a 3D model of a prechamber created for a spark-ignition engine and focuses on the numerical analysis of the fluid flow inside the modified chamber. This kind of analysis is very important once it allowed evaluating aspects like turbulence parameters, pressure inside the chamber and prechamber, fluid recirculation and a possible prechamber’s geometry for the engine. The studies were done in a four valve Single Cylinder Research Engine - SCRE. For the numerical modeling and fluid flow investigation it was used STAR-CD Software. The numerical results permitted to characterize the fluid flow in the modified engine and compare it with the standard engine, which showed significant differences and an interesting potential.

In this paper, particle image velocimetry (PIV) and computational fluid dynamics (CFD) were employed to a qualitatively and quantitatively study in the behavior of the intake-generated steady flow in a four valve spark ignition single cylinder research engine. Steady flow experimental characterization was made for different intake valve lift values. PIV was used to investigate the flow pattern generated within the engine cylinder. The measurements were taken in the symmetry vertical plane between the inlet and outlet valves. These same conditions were modeled using Star-CCM+ commercial package. The CFD model was used as a less expensive alternative to make a deeper study of the flow field. Velocity fields and intake valves discharge coefficient were compared and analyzed, resulting in a good correlation in relation to the optical experiment.

The simulation of the fluid dynamics in internal combustion engines has become more important in the past few years for research, development and design of that equipment. The Computational Fluid Dynamics (CFD) methodology is able to analyze the fluid flow in regions the experimental technology cannot afford to. Using a single cylinder research engine, the calculation can be validated from in-cylinder pressure and temperature measurements, also with velocity fields and the related variables. This paper presents the evaluation of the numerical results for tumble and swirl coefficient on internal combustion engines along with its validation. The commercial code STAR-CD, with the ES-ICE module, specific for internal combustion engine, was used for the CFD calculation. Grid independence studies in space and time has been made for reliability of the results.

Fulfill emission restrictions is the most challenging task of future engines development. In this context, improvements with regard to the spray and mixture formation in internal combustion engines are necessary. Experimental investigation and numerical simulation have been used to predict and analyze complex in cylinder processes. In this paper, a diesel spray characterization using optical diagnostics was made in order to provide input data and boundary conditions for a diesel spray computational fluid dynamics simulation (CFD), using the Eulerian-Lagrangian model. Combining the advantages of Eulerian and Lagrangian approaches, this model is able to predict continuously the whole spray evolution. The main difficulty of numerical spray simulation is the correct representation of the two characteristic spray zones: dense near the nozzle and dilute downstream.

The design and development of highly efficient internal combustion engines require a thorough investigation of the fluid dynamic processes. This paper presents the experimentally determination and computational fluid dynamics simulations of the intake valves discharge coefficients of a four valve spark-ignition single cylinder research engine. The mass flow rate and air pressure were measured directly in the intake port for six different values of valve lift (4.68; 6.16; 7.48; 8.62; 9.46; and 10.49mm). The theoretical mass flow rates were obtained based on considerations of subsonic flow. Simulations were carried using the Star CCM+ commercial code. Mesh independence studies, using the velocity fields as monitors, have been made for reliability of the simulations. As a result, a methodology was successfully implemented to obtain the discharge coefficients experimentally and the simulations were validated with a maximum deviation of 6.62%.