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When a vehicle is driven in snowy conditions, if a proper air intake design is not adopted, the snow lifted by the leading vehicles may penetrate into the engine air intake, in case of large snow ingress amount, causing a power drop. The evaluation of such risk for the intake is carried out through climatic wind tunnel tests, which cannot be conducted at the early stage of vehicle development when the prototype vehicle does not exist. In order to study that risk prior to the prototype vehicle delivery, computational fluid dynamics (CFD) which predicts the snow ingress amount accurately was established with taking into account unsteady air flow and snow accumulation. Large Eddy Simulation (LES) was used to reproduce the unsteady flow field, leading to a good agreement of the flow downstream from the snow generator with the experimental one measured by Particle Image Velocimetry (PIV). As for the snow particle behavior model, the Lagrangian method was chosen.

Optimization methodology employing CFD for the aerodynamic design of automotive car styling is presented. The optimization process consists of three stages: Design of Experiments (DOE), Response Surface Modeling (RSM), and optimization algorithm execution. RSM requires a number of CFD calculations in order to ensure its accuracy, making it difficult to apply the RSM to aerodynamic design optimization. In order to resolve this issue, Adaptive Multi Stage RSM (AMS-RSM) was conceived. This method provided the response surface its required accuracy and robustness. The optimization process was realized by constructing an automatic optimization system consisting of software.

The following two objectives were set for the development of predictions for snow ingress into the air intake system. To enable snow ingress predictions in the design stage so that vehicles can be developed in a short period of time. To guarantee performance in very cold regions such as Canada. To achieve these objectives, it was decided to develop snow ingress prediction tools that use computational fluid dynamics (CFD). First, research was conducted in Canada to collect the snow information that was required for the simulation. In this research, snow particle measurement equipment was used to measure in detail the number of snow particles and their diameters. The research results that were obtained were reflected in the simulation, and a correlation was found between the calculations and test results obtained in Canada. Finally, tools were developed to facilitate results analysis from the snow ingress simulation.

The accuracy of the injection rate meter based on W. Zeuch's method in the measurement of multiple injection rate and amount was calibrated using a small cam driven piston that is driven by an electric motor. For the pre- or early-injection, a sensor with a high sensitivity can be applied to measure the small pressure increase due to the small injection amount. In case of the multiple injection that has the post and/or late injection, a pressure sensor with a low sensitivity must cover not only the large pressure increase due to the main injection but also the small pressure increase due to the post and/or late injection because the output of the high sensitivity sensor is saturated after the main injection. So the linearity of the low sensitivity pressure sensor was calibrated with the cam driven piston prior to the experiment with the actual injection system.

The injection rate meter based on W. Zeuch's method was improved to meet the recent requirement for precise measurement of the multiple injection rate and amount in CDI (Common rail Direct Injection) diesel engines. A pressure sensor with a high sensitivity was added to measure the small pressure increase due to the pilot injection and after injection. At the same time a flow meter having a high accuracy was installed in the discharge pipe line to obtain a correction factor to the modulus of elasticity of volume. As a result it became possible to measure the multiple injection amount at an accuracy of ±0.2mm3/stroke in a range up to 40mm3/stroke.

A new method to measure accurately the compression ratio of automobile engines in the manufacturing line is proposed. To determine the compression ratio of an engine, the cylinder volume at a piston position is measured with a detecting probe which is featured with a pressure sensor of high sensitivity and a micro piston driven by an electromagnetic coil. The probe is attached to the cylinder head at the spark plug hole. The air in the cylinder at TDC is compressed sinusoidaly at a frequency of 70Hz by the micro piston with a diameter of 5mm. The volume at TDC can be determined by detecting the pressure change caused by the compression by the micro piston. In this report, the principle of the method is described and effects of geometry of the chamber space and other parameters on the measuring accuracy are discussed. Polytropic exponent of the pressure change was found most crucial in this method.

An experimental evaluation of the reliability of the Zeuch's method was carried out. The following were derived: 1) cavitation limits the minimum back pressure available; 2) the injection rate measured by the Zeuch's method agrees with that by the W.Bosch's method; 3) the effect of dynamic pressure of the injected fuel jet has a negligible effect on the pressure sensor which is attached to the chamber wall; and 4) the high-frequency noise after the end of injection observed in the Zeuch's measurement can be effectively removed by either a low-pass filter or an inverse Fourier transform processing.

A new instrument for the measurement of fuel injection rate in diesel engines was developed. The instrument, whose measurement principle is based on the Zeuch's method, i.e., the constant volume method, incorporates a device for the precise calibration of the volume elasticity of the fuel. This instrument was proved experimentally to have a capability of measuring injection rate with ± 1% accuracy up to an injection pump rotating speed of 2500rpm.