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Computer Aided Engineering (CAE) has become a vital tool for product development in automotive industry. Increasing computer models are developed to simulate vehicle crashworthiness, dynamic, and fuel efficiency. Before applying these models for product development, model validation needs to be conducted to assess the validity of the models. However, one of the key difficulties for model validation of dynamic systems is that most of the responses are functional responses, such as time history curves. This calls for the development of an objective metric which can evaluate the differences of both the time history and the key features, such as phase shift, magnitude, and slope between test and CAE curves. One of the promising metrics is Error Assessment of Response Time Histories (EARTH), which was recently developed. Three independent error measures that associated with physically meaningful characteristics (phase, magnitude, and slope) were proposed.

Air rush noise is exhaust gas driven flow-induced noise in the frequency range of 500-6500 Hz. It is essential to understand the flow physics of exhaust gases within the mufflers in order to identify any counter measures that can attenuate this error state. This study is aimed at predicting the flow physics and air rush noise of exhaust mufflers in the aforementioned frequency range at a typical exhaust flow rate and temperature. The study is performed on two different muffler designs which show a significant air rush noise level difference when tested on the vehicle. The transient computational study was performed using DES with 2nd order spatial discretization and 2nd order implicit scheme for temporal discretization in StarCCM+. To compare with test data, a special flow test stand is designed so that all high and low frequency contents emanating from the engine are attenuated before the flow enters the test part.

High concentrations of diesel fuel can accumulate in the engine oil, especially in vehicles equipped with diesel particle filters. Fuel dilution can decrease the viscosity of engine oil, reducing its film thickness. Higher concentrations of fuel are believed to accumulate in oil with biodiesel than with diesel fuel because biodiesel has a higher boiling temperature range, allowing it to persist in the sump. Numerous countries are taking actions to promote the use of biodiesel. The growing interest for biodiesel has been driven by a desire for energy independence (domestically produced), the increasing cost of petroleum-derived fuels, and an interest in reducing greenhouse gas emissions. Biodiesel can affect engine lubrication (through fuel dilution), as its physical and chemical properties are significantly different from those of petrodiesel. Many risks associated with excessive biodiesel dilution have been identified, yet its actual impact has not been well quantified.

An L16 orthogonal array parameter Design of Experiment (DOE) evaluated six design parameters of the mating thread interface between the exhaust manifold outlet flange and jointing stainless steel fastener. The objective of this study was to identify optimal parameters for the redesign the thread interface by ensuring 100% seating of the fastener into the manifold flange (here after referred to as stud seating). Since the current fastener and manifold outlet flange interface threads do not always achieve the design objectives, due in part to a form of abrasive wear, consideration was given to develop a testing strategy that would quantify the amount of remaining thread engagement for a given stud length. This testing strategy ensured that the control parameters considered in this experiment would reveal main effects and interactions between the stud and tapped hole threads thus providing the necessary parameters for the redesign on the joint threads.

The advent of turbochargers and the Eco-Boost technology at Ford in gasoline engines creates new challenges that need to be addressed with innovative designs. One of them is flow induced noise caused by airflow entering the turbocharger during off design operation. At certain vehicle operation conditions, the mass flow rate and pressure ratio are such that compressor wheel can generate a wide range of acoustic frequencies. Characterization of ‘whistles’ or pure tonal noises, ‘whoosh’ or broad band frequency noise caused by flow separation from the blade surfaces, and chirps, where the frequency increases or decreases with time are a few of the common error states. Understanding the fundamental mechanisms of such noise generation is necessary for developing effective countermeasures for the noise source generation. Computational Aero-Acoustic (CAA) analyses are performed to study the effects of inlet and outlet conditions to find the source of the noise.