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Acoustical tuning of intake manifolds is a common practice used to achieve gains in volumetric efficiency in a pre-determined region on the torque curve. Many methods exist for acoustical tuning of the intake including a variation of the Helmholtz resonator model by Engelman as well as the organ pipe models by Ricardo and Platner. In this work a new intake tuning model has been developed using an Impedance Transform Model along with a minimal set of limiting assumptions. Unlike the models of Engelman and Platner, this model can accommodate any intake geometry. The model can also be used to analyze specific points in the intake system or the entire system rather than just the intake runners. Model verification consisted of resonance testing of three different Helmholtz resonators as well as dynamometer testing of a Honda CBR F3 four-stroke SI engine using three different intake system geometries.

This paper presents the development of a Plastic Valve Cover System (PVCS) using Finite Element Analysis (FEA). This approach results in a shorter development period and reduced costs. The numerical methodology is divided into two steps. First, a two-dimensional analysis is of the rubber components (gasket, grommet) determines the load-deflection response and the system equilibrium for the complete range of component tolerances. These curves are utilized in a second step. Applied to a three-dimensional model of the cover, the analysis determines the valve cover optimal design. The paper describes other relevant issues related to PVCS's such as: a) influence of strain damage on elastomeric response. b) element type, size and order selection for optimum modeling. Comparisons with experimental results are presented and the appropriate conclusions are drawn.

To meet the future emission targets for Diesel engines, one trend is the use of Catalyzed Diesel Particulate Filters (CDPF). Catalyzing the filter, however, alters filter behavior. In particular, alteration in filter permeability imparts a significant change in the filter's performance. To understand the impact of the catalyst coating on a DPF, engine tests have been conducted to measure the pressure drop across DPFs with different catalyst coatings, cell densities, and soot loadings. The tests were performed over a range of engine speeds and loads, with a corresponding range in exhaust flow rates and temperatures. A pressure drop model based on previous work for uncatalyzed filters has been modified and validated for CDPFs. To achieve optimum design for DPF's, a parametric study comparing the influence of catalyst, cell density, wall thickness, filter length and diameter was done.