Development of a single-cylinder engine transient test system for hardware-in-the-loop cold-start emission testing

The purpose of this research was to further develop and utilize a single-cylinder research engine transient test system as a representative hardware-in-the-loop (HIL) multi-cylinder dynamic simulation and evaluate the effects of the added test system manipulation on transient emission output during cold-start operation. Typically used for a limited range of steady-state tests, the single-cylinder engine has drawbacks associated with the missing dynamic interactions present in a multi-cylinder engine. These interactions include the rotational, air intake, exhaust gas, and heat transfer dynamic coupling between cylinders in a multi-cylinder engine system.;The initial phases of this research included the restructuring of the research laboratory facility, test subsystem hardware updates which include accommodating a new engine design and transient heat transfer system serving to provide the possibility to simulate temperature transients, and software updates including control strategy revision for each of the primary test system constituents and engine strategy calibration. The performance of each device was tested and tuned independently to achieve the desired response characteristics before integration into the virtual multi-cylinder HIL simulation.;The results of the HIL simulation during the cold-start transient operation showed very good replication of the measured performance of the target multi-cylinder engine. The rotational and air intake dynamics were reproduced with excellent tracking, and the execution of an engine management strategy measured from the multi-cylinder engine's control unit during the simulation improved correlation of the transient exhaust gas output characteristics between the two engine systems. It was concluded that this research work represents significant progress in transient powertrain test system development, opening the possibility to conduct powertrain performance testing and control system development using only single-cylinder engine hardware.;It was recognized that the implemented engine management strategy, as well as other discrepancies between the two test beds, limited the validation scope. Suggestions for addressing these limitations, as well as future avenues for evaluation with more extensive utilization of the transient heat transfer system's capabilities, are given.