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Reducing friction in crankshaft bearings during cold engine operation by heating the oil supply to the main gallery has been investigated through experimental investigations and computational modelling. The experimental work was undertaken on a 2.4l DI diesel engine set up with an external heat source to supply hot oil to the gallery. The aim was to raise the film temperature in the main bearings early in the warm up, producing a reduction in oil viscosity and through this, a reduction in friction losses. The effectiveness of this approach depends on the management of heat losses from the oil. Heat transfer along the oil pathway to the bearings, and within the bearings to the journals and shells, reduces the benefit of the upstream heating.

As an index to control the heat release of auto-ignition combustion, our previous paper introduced a concept of ΔT. It was the difference between the adiabatic flame temperature and the initial in-cylinder gas temperature before the heat release, i.e., ΔT physically represents the heat capacity of the in-cylinder gases relative to the calorific value supplied in a cycle. Firing tests of a four-stroke auto-ignition gasoline engine revealed that the heat release process could be successfully controlled when ΔT was maintained at a proper level. This paper evolved the ΔT theory into the every possible gas exchanging state in the four-stroke engines and found out a chain of the low-temperature combustion cycle (LTC), which continuously varied from the spark-ignition (SI) to auto-ignition (AI). By using a hydraulic-electromagnetic fully-free valve actuator system, the LTC was examined in our 650 cm₃ single-cylinder experimental-engine.

A cold turbocharger test facility was designed and developed at The Ohio State University to measure the performance characteristics under steady state operating conditions, investigate unsteady surge, and acquire acoustic data. A specific turbocharger is used for a thermodynamic analysis to determine the capabilities and limitations of the facility, as well as for the design and construction of the screw compressor, flow control, oil, and compression systems. Two different compression system geometries were incorporated. One system allows compressor performance measurements left of the surge line, while the other incorporates a variable-volume plenum. At the full plenum volume and a specific impeller tip speed, the temporal variation of the compressor inlet and outlet and the plenum pressures as well as the turbocharger speed is presented for stable, mild surge, and deep surge operating points.

ACOUSTOMIZE™ is a new method of acoustic evaluation used for the purpose of understanding and optimizing NVH performance of vehicles. The following paper documents a case study of the ACOUSTOMIZE™ test methodology on a passenger car BIW. This study includes an analysis of noise flow through BIW locations, a comparison of noise sound levels through BIW cavities with and without a sound treatment package and a comparison of the original cavity sealing design package consisting of baffles, tapes and baggies to low density polyurethane NVH Foam. The results of the study show detection of complex BIW pass throughs that the body leakage test (BLT) was not able to find. In addition, the data shows improved noise reduction with the low density polyurethane foam versus the original cavity sealing design package.

Gear meshing noise is a common noise issue in manual transmission, its noise generation mechanism has been studied extensively [1, 2]. But most of time we have situations where multiple gear sets are connected in series and the noise and vibration behavior for a multi-stage gear can be quite different due to vibration inter-actions or interferences among multiple gear sets. In this paper, a two-stage gear driveline model was built using MSC ADAMS. Vibration order contents of a two-stage gear driveline were analyzed by both CAE simulation and theoretical calculations. In addition to gear meshing vibration orders of each gear set, the orders resulted from modulations between individual gear meshing and their harmonics were evident in the results. These special order contents were verified by experimental results, and also evidenced on transmission end of line tester results at transmission supplier GJT in Ganzhou, China.

In order to simulate the valve behavior of an engine that uses a hydraulic lash adjuster (HLA), it is necessary to accurately reproduce the dynamic characteristics of the HLA in the model. Formerly, the model used values from drawings and values based on past experiences, and did not reflect actual driving conditions such as oil properties, leaked oil quantity, or oil aeration rate. We therefore developed a technique to reproduce HLA unit dynamic characteristics in a high-accuracy simulation. This representation was made possible using a unit excitation test to quantify the HLA unit dynamic characteristics in four categories: HLA stiffness, load response delay of the plunger, sinking displacement after relaxation, and lissajous curve of load vs. displacement. The effectiveness of this model calibration technique was confirmed through comparison of unit dynamic characteristics in a unit excitation test and a calibrated simulation.

Honda developed a new generation 1.6L diesel engine as a part of technologies for high driving performance and good fuel economy. This new engine is equipped on Civic (C Segment, 5 doors), launched as a new European model in 2013. This engine has some technologies achieving both good fuel economy and low emission, and met Euro5 emission regulation. And the Civic achieved CO2emission of 94 g/km in NEDC, a reduction of 14.5% in CO2 emission against the previous diesel engine of Honda. [1] This engine has the dual EGR system composed of HP-EGR and LP-EGR, one of the technologies introduced to increase fuel efficiency. In this paper, some issues for the dual EGR system control and countermeasures for them will be described. In order to control each EGR mass flow, two or more valves (HP-EGR valve, LP-EGR valve and intake throttle) should be regulated cooperatively.

Variable nozzle turbine (VNT) technology has become a popular technology for diesel engine application. To pivot the nozzle vane and adjust the turbine operating condition, nozzle clearances are inevitable on both the hub and shroud side of turbine housing. Leakage flow formed inside the nozzle clearance leads to extra flow loss and makes the nozzle exit flow less uniform, thus further affects downstream aerodynamic performance of the rotor. As the leakage mixing with nozzle wake flow, the process is highly unsteady, which increases the fluctuation amplitude of transient load on the rotating turbine wheels. In present paper, firstly steady CFD analysis of a turbocharger turbine was performed at different nozzle openings. Then unsteady simulation of the turbine was carried out to investigate the interaction between the leakage flow through nozzle clearance and the main flow. Nozzle clearance's effect on turbine performance was investigated.

Design and development of an electrohydraulically actuated gas sampling valve is presented for use in auto engine combustion studies. The valve was developed with particular emphasis on sampling within the vicinity of the wall quench layer, requiring minimum leakage rates to avoid sample contamination and flush seating of the valve-stem to valve-seat to avoid perturbations of the wall layer. Response in the range of 0.4 to 1.0 milliseconds is attainable for variable valve lifts measured between 0.01 to 0.30 mm while using a net sealing force of approximately 750N. Gas leakage rates ranged from 0.05% to 1% of the sample mass flow rate when sampling from estimated distances from the wall of 0.3 mm to 0.03 mm, respectively, at a cylinder pressure of 10 bar. The gas sampling valve is presently coupled to a gas chromatograph to measure concentrations of major species components.

Diesel combustion and emissions is largely spray and mixing controlled. Spray and combustion models enable characterization over a range of conditions to understand optimum combustion strategies. The validity of models depends on the inputs, including the rate of injection profile of the injector. One method to measure the rate of injection is to measure the momentum, where the injected fuel spray is directed onto a force transducer which provides measurements of momentum flux. From this the mass flow rate is calculated. In this study, the impact of impingement distance, the distance from injector nozzle exit to the anvil connected to the force transducer, is characterized over a range of 2 - 12 mm. This characterization includes the impact of the distance on the momentum flux signal in both magnitude and shape. At longer impingement distances, it is hypothesized that a peak in momentum could occur due to increasing velocity of fuel injected as the pintle fully opens.

Compared to conventional injection techniques, Gasoline Direct Injection (GDI) has a lot of advantages such as increased fuel efficiency, high power output and low emission levels, which can be more accurately controlled. Therefore, this technique is an important topic of today's injection system research. Although the operating conditions of GDI injectors are simpler from a numerical point of view because of smaller Reynolds and Weber numbers compared to Diesel injection systems, accurate simulations of the breakup in the vicinity of the nozzle are very challenging. Combined with the complications of experimental techniques that could be applied inside the nozzle and at the nozzle exit, this is the reason for the lack of understanding the primary breakup behavior of current GDI injectors.