Application of Grey–Taguchi based multi-objective optimization strategy to calibrate the PM–NHC–BSFC trade-off characteristics of a CRDI assisted CNG dual-fuel engine

The present work attempts to simultaneously reduce the BSFCeq, NHC and PM emissions of a CRDI assisted diesel engine under CNG-diesel dual-fuel mode. Load, fuel injection pressure and CNG energy share were chosen as input parameters with NHC, PM and BSFCeq as the response variables. To reduce the experimental effort the experiments have been performed by employing Taguchiʹs L16 orthogonal array. In order to search for the optimal process response, the Grey relational analysis is employed for solving the optimization problem. The optimal combination of the input parameters was obtained using the Grey relational grade and signal-to-noise ratio as a performance index, which achieved the desired response characteristics. The optimal combination so obtained was further confirmed through experimentation. Among the three, load was found to be the most influencing factor.