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The ability to make fully resolved turbulent scalar field measurements has been demonstrated in an internal combustion engine using one-dimensional fluorobenzene fluorescence measurements. Data were acquired during the intake stroke in a motored engine that had been modified such that each intake valve was fed independently, and one of the two intake streams was seeded with the fluorescent tracer. The scalar energy spectra displayed a significant inertial subrange that had a −5/3 wavenumber power dependence. The scalar dissipation spectra were found to extend in the high-wavenumber regime, to where the magnitude was more than two decades below the peak value, which indicates that for all practical purposes the measurements faithfully represent all of the scalar dissipation in the flow.

The ride values of passenger cars are investigated for Korean subjects based on the vibration of the human bodies. When three subjects are excited by driving a vehicle on road, their responses of acceleration are measured at 12 points on their bodies according to Griffin's 12 axis system (3 translational axes on a seat surface, 3 rotational axes on a seat surface, 3 translational axes at the seat back and the 3 translational axes at the feet). Since one of the most important parameters for ride comfort is the level and duration of the root mean square acceleration experienced, the ride values, such as the seat effective amplitude transmissibility, the component ride value, and the overall ride value based on acceleration root mean square are evaluated for different four vehicles using frequency weighing functions and axis multiplying factors. The ride indices are also studied considering to the seat dynamic characteristics with subjects.

The ride values of seven cars(six passenger car and one RV car) are evaluated for 4 subjects based on the vibration of the bodies. And the seat qualities are investigated with the SEAT(seat effective amplitude transmissibility) value. The evaluated values are arranged as DB in html files. Since one of the most important parameters for ride comfort is the level and duration of the root mean square acceleration experienced, the acceleration responses of subjects are measured at 8 points on their bodies(3 Translational axes on the seat surface, 3 translational axes at the feet and 2 axes(x,z) at the backrest) when the subjects are excited by driving a vehicle on the road. The ride values such as the overall ride value, the component ride values and the seat effective amplitude transmissibility based on acceleration root mean square are evaluated for different seven vehicles using frequency weighting functions and axis multiplying factors.

This paper describes a method to separate structure-borne noise, which comes from the shock absorber, from the measured vehicle interior sound pressure. The transfer path analysis (TPA) was used. Shock absorber was considered as an input source while the sound pressure at the driver seat as its output. It was found that the sound pressure at the driver seat position and accelerations at the shock absorber mounting points are strongly correlated. Using one-third octave band analysis, the contribution of shock absorber structure-borne noise to the driver seat sound pressure was analyzed. Also the relationship between the measured acceleration and sound pressure was studied.

Acoustic holography is adopted in identifying the noise sources of a vehicle's underbody. Wind noise from a vehicle's underbody accounts for a large portion of the overall noise level due to the complex flow structure. Current study presents the development process of acoustic holography in the vehicle underbody. Difficulties associated with using acoustic holography as well as the method to eliminate the effect of sound reflection will be addressed.

The noise characteristics of four camera systems representative of those typically used for laser-imaging experiments (a back-illuminated slow-scan camera, a frame-straddling slow-scan camera, an intensified slow-scan camera and an intensified video-rate camera) were investigated, and the results are presented as a function of the signal level and illumination level. These results provide the maximum possible signal-to-noise ratio for laser-imaging experiments, and represent the limit of quantitative signal interpretation. A calibration strategy for engine data that limits the uncertainties associated with thermodynamic and optical correction was presented and applied to engine data acquired with two of the camera systems. When a rigorous analysis of the signal is performed it is seen that shot noise limits the quantitative interpretation of the data for most typical laser-imaging experiments, and obviates the use of single-pixel data.

In this paper, the vibro-acoustic transmission characteristics are investigated in the view point of the airborne noise in the interior cavity due to the tire wall vibrations. The analysis is carried out by categorizing the airborne noise transfer path into the two separate consecutive events. First, the noise transfer from the vibrating tire wall to the exterior car panels is modeled by using the direct boundary element method (BEM). To this end, after discretizing the whole geometry of exterior body panels, tires, and ground into BEM models, vibro-acoustic transfer characteristics are investigated at several frequency components associated with the cavity resonances of tire. Here, cavity resonance frequencies of tire are estimated by BEM and the distribution of tire wall vibrations excited by a special vibro-acoustic source is measured at those frequencies.

A hybrid-integrated approach is presented to analyze the structure-borne booming noise in a passenger car. We identify the critical noise transfer path from the engine to the target by the transfer path analysis. However, it does not give the answer for why the noise transfer function is so high at that path. Therefore, an integrated approach which applies the analysis tools systematically is presented. The running mode analysis gives us the operating motion of each component in the body structure. However, there is no evidence that the components that vibrate severely are the sources of this problem. The modal characteristics from the structural modal test enable us to describe the real motion of the body completely in terms of the structural modes. Similarly, the acoustic modal characteristics from the acoustic modal analysis describe the fundamental behavior of the cabin cavity.