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Predictive crash sensing and deployment control of safety systems require reliable and accurate kinematic information about potential obstacles in the host vehicle environment. The projected trajectories of obstacles in the path of the vehicle assist in activation of safety systems either before, or just after collision for improved occupant protection. This paper presents an analysis of filtering and estimation techniques applied to imminent crash conditions. Optimization of design criteria to achieve required response performance, and noise minimization, are evaluated based on the safety system to be activated. The predicted target information is applied in the coordinated deployment of injury mitigation safety systems.

Computational fluid dynamics simulations of the gas exchange process in a crankcase-scavenged, two-stroke engine were used to study the scavenging characteristics of the engine over the whole operating range and to investigate the effects of various design changes. The simulations used time-dependent velocity and pressure boundary conditions in the transfer and exhaust ports, respectively, which were obtained from a one-dimensional gas exchange code. The bulk flow characteristics, scavenging and trapping efficiencies, computed from these simulations compared well with experimental data. Investigation of the highest load and speed case showed that moderate port angle variations only weakly influenced the scavenging efficiency and velocity field. On the other hand, modifying the exhaust pressure to simulate single cylinder operation had a more significant effect on the scavenging and showed a possible way to control the gas exchange process.

Application of Atmospheric Pressure Chemical Vapor Deposition (APCVD) to the production of thin film coated glass is addressed in this study. Several layers of thin solid film are deposited on the surface of the glass as it moves underneath the APCVD applicator system at high temperature. High velocity in the vicinity of the deposition zone is desirable. Two separated regions of recirculating fluid are generated as the fluid jet exits the injector. The memory effect in the form of thickness streaks, corresponding to the location of the inlet holes located upstream in the upper manifold feed channel, are evident on the thin film. Also, the velocity field in the injector channel is influenced by the location of the holes. This nonuniform gas flow across the glass causes a color variation of the coating. Effective mixing of the gas streams is required to treat the hole memory problem. However, premature reaction is to be avoided.

Wind noise is a major problem in automobiles today. It is especially significant since powertrain and tire noise continue to diminish and quieter electric vehicles are on the horizon. The Wind Noise Modeller is an analytical tool that accurately computes sound pressure levels (SPL) at the driver's ear caused by wind noise. Using Statistical Energy Analysis (SEA), it accounts for the sound radiated both from the vibrating side glass and through the door seals. Incorporated into an EXCEL spreadsheet that runs on a PC or workstation, it automatically computes, plots, and tabulates both linear & A-weighted SPL, and compares it to user-supplied experimental data. It can quickly evaluate the effects of vehicle changes on the resulting noise level. When coupled with reliable CFD computations, it can be used very early in the design process to help minimize wind noise. This should greatly reduce wind tunnel tests needed for wind-noise estimations.

The lattice Boltzmann (LB) method, which is closely related to the lattice Gas (LG) method, will be investigated in detail in this paper. The LG method is boolean in nature using only bits to indicate the presence or absence of a particle moving in a particular direction and speed. The absence of floating point operations gives the LG method unconditional numerical stability but restricts it to specialized hardware that can perform the Boolean logical operations efficiently. The Boolean character also results in a noisy signal that must be averaged over space/time for reliable estimates. The LB method, on the other hand, tracks the distribution functions (or time averages) of the particles. As a result, floating point numbers have to be used and so the method is not boolean. While this makes the LB method susceptible to instabilities due to accumulation of round-off errors, it allows the LB method to use a variety of existing computer platforms.

The current ability of the Virtual Aerodynamic/ Aeroacoustic Wind Tunnel to predict interior vehicle sound pressure levels is demonstrated using an automobile model which has variable windshield angles. This prediction method uses time-averaged flow solutions from a lattice gas CFD code coupled with wave number-frequency spectra for the various flow regimes to calculate the side window vibration from which the sound pressure level spectrum at the driver's ear is determined. These predictions are compared to experimental wind tunnel data. The results demonstrate the ability of this methodology to correctly predict wind noise spectral trends as well as the overall loudness at the driver's ear. A more sophisticated simulation method employing the same lattice gas code is investigated for prediction of the time-accurate flow field necessary to compute the actual side glass pressure spectra.