Test cell set-up to enable drive-cycle testing of a variable valve actuation enabled camless diesel engine

The previous facility which was used for engine testing at Purdue\u27s Ray W. Herrick Laboratories utilized an eddy current dynamometer which is only suited for steady-state testing and throttle snaps. To better utilize a pre-existing camless diesel engine, which is is enabled via variable valve actuation, it was desired to perform transient drive-cycle tests. To accomplish this goal, a variable frequency drive AC dynamometer was required. Given that a brand new facility was constructed, the team was presented with an opportunity for ground up design of a test cell. The new test cell\u27s operation was proved out using a cammed diesel engine before moving the vairable valve actuation (VVA) enabled camless engine over. The research group\u27s best practice is to only utilize the VVA engine when collecting novel or experimental data as additional run time on this engine increases the risk of damage due to valve-to-piston interference. The goal of proving out the test cell with the cammed engine was to validate that engine operation and data collection was \u27\u27as good as or better than the previous test facility, and to solve any issues preventing the group from reaching that goal. Data acquisition results from the new test cell had noise issues which were worked out before moving over the VVA engine from the previous test cell. Fuel metering with a Cybermetrix fuel metering unit (FMU) proved to be more difficult than just plug and play, with fully functional and reliable operation taking place after the move. While the test cell\u27s room ventilation proved fully functional, additional research and work was required to hook up the conditioned combustion air system. Transient drive-cycle testing was performed with the cammed engine, and statistical analysis was performed which confirmed that the feedback speed and torque matched the reference speed and torque within EPA guidelines. This same analysis was later performed with the VVA engine and also showed capability of the VVA engine to perform repeatable drive-cycle tests. The new test cell continues to see new additions, with future work including the installation and validation of a full diesel after-treatment system which will allow for research into improving not only engine-out emissions but also tailpipe emissions through studies of the dynamic interactions between the individual exhaust components. The scope of VVA enabled diesel engine research in the Cummins Power Lab has increased from steady-state testing to transient drive-cycle testing which is more representative of how the engine is used by the end-customers