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The interface between a plenum and primary runner in log-style intake manifolds is one of the dominant sources of flow losses in the breathing system of Internal Combustion Engines (ICE). A right-angled T-junction is one such interface between the plenum (main duct) and the primary runner (sidebranch) normal to the plenum's axis. The present study investigates losses associated with the combining flow through these junctions, where fluid from both sides of the plenum enters the primary runner. Steady, incompressible-flow experiments for junctions with circular cross-sections were conducted to determine the effect of (1) runner interface radius of 0, 10, and 20% of the plenum diameter, (2) plenum-to-runner area ratio of 1, 2.124, and 3.117, and (3) runner taper area ratio of 2.124 and 3.117. Mass flow rate in each branch was varied to obtain a distribution of flow ratios, while keeping the total flow rate constant.

An experimental study of the acoustic characteristics of automotive catalytic converters is presented. The investigation addresses the effects and relative importance of the elements comprising a production catalytic converter assembly including the housing, substrate, mat and seals. Attenuation characteristics are measured for one circular and one oval catalytic converter geometry, each having 400 cell per square inch substrates. For each geometry, experimental results are presented to address the effect of individual components in isolation, and in combination with other assembly components. Additional experiments investigate the significance of acoustic paths around the substrate and through the peripheral wall of the substrate. The experimental results are compared to address the significance of each component on the overall attenuation.

One of the dominant sources of flow losses in the intake system of internal combustion engines (ICE) with log-style manifolds is the interface between the plenum and primary runner. The present study investigates such losses associated with the dividing flow at the entry to primary runner with geometries representative of those used in ICE. An experimental setup was constructed to measure the flow loss coefficients of T-junctions with all branches of circular cross-section. Experiments were conducted with seven configurations on a steady-flow bench to determine the effects of: (1) interface radius equal to 0, 10, and 20% of the primary runner diameter, (2) plenum to primary runner area ratios of 1, 2.124, and 3.117, and (3) primary runner taper including taper area ratios of 2.124 and 3.117. The last two categories employed 20% interface radii. The total mass flow rate was also varied to investigate the effect of Reynolds number Re on loss coefficients.

Meeting the increasingly stringent regulations for spark-ignited (SI) internal combustion engines requires understanding the complex chemical and physical processes that occur during combustion. Short time scales and extremes in temperature and pressure make detailed measurements in real combustion systems difficult. To augment the experimental measurements numerical models for combustion have been developed. These models can provide insight into the non-linear interactions that occur during combustion and help to guide the design of the system by providing information on parameters that cannot be measured directly. This paper presents a newly-developed turbulent combustion model that is based on the concepts of the turbulent entrainment model. Quasi-dimensional engine simulations have used models of this type for the past two decades with considerable success. In this study, the model is formulated in a manner suitable for coupling with CFD solvers in one or more spatial dimensions.

Application of steady-flow correlations to characterize flow losses in complex piping systems is well established for non-transient fluid transport engineering. As a result, the literature contains numerous correlations relating flow (or pressure) losses to the piping system geometry. The present study applies these correlations to an intake manifold of a four cylinder engine to identify regions in the manifold that contribute most significantly to the system flow loss; results showed that the primary runner entrances accounted for over half of the total system loss. With this finding, four manifolds were designed and tested on a steady-flow bench and on an engine. Reduced flow losses resulted in improved peak engine performance at the expense of low speed volumetric efficiency. Primary runner pressures at peak performance conditions were analyzed in both the time and frequency domain.