Singh, S., Asthana, S., and Kumar, N., "Development of an Intake Runner of a CI Engine for Performance Enhancement and Emission Reductions Due to Variations in Air Flow Pattern within the Runner," SAE Technical Paper 2016-01-1015, 2016, doi:10.4271/2016-01-1015.
Recent scenario of fossil fuel depletion as well as rising emission levels has witnessed an ever aggravating trend for decades. The solution to the problems has been addressed by investments and research in the field of fuels; such as the use of cleaner fuels involving biodiesel, alcohol blends, hydrogen and electric drivelines, as well as improvement in traditional technologies such as variable geometry systems, VVT load control strategies etc. The developments have highlighted the enormous potential present in such systems in terms of maximizing engine efficiency and emission reductions. The present paper aims at designing and implementing an intake runner system for a CI engine capable of providing flexibility with variations in operating conditions. Primarily, the design aims at altering the air flow phenomenon within the primary intake of the engine by inducing swirl in the runner through a secondary runner. Existing research that provides a baseline for this paper has highlighted the improvements in BSFC, UHC and CO emissions by employing modifications in the intake manifold on single as well as multi-cylinder engines. For the testing phase, a single cylinder VCR diesel engine was selected to simplify the designing and implementation process. The designed intake runner conflated two control strategies: variation in the effective length of intake air travel and variation in the entry angle from the secondary to the primary runner which alters the swirl within the runner. Since the engine considered was a constant speed CI engine, only the variations in entry angle have been presented with corresponding impact on the performance and emission parameters. The designing of the runner has been sub-divided into various steps. Firstly, flow visualization and design optimizations have been performed using ANSYS CFX as the analysis software and Solidworks as the designing software. The indirect validation of the CFX results was done by employing a steady state test rig for the manifold with constant pressure drop across the inlet and outlet. The final stage involved implementing the runner on a constant speed VCR engine operated at a constant compression ratio for the testing. The results are presented as a comparison of performance and emission parameters such as brake torque, power, fuel consumption, NOx, CO, CO2 and UHC for the baseline diesel engine and a specific entry angle for the designed runner. The design, though presented in the current paper as a modification for single cylinder engine, is capable of being employed on multi-cylinder engines if modified accordingly.