Experimental and Simulated Pressure Measurements of a Two-Stroke Large Bore Natural Gas Spark-Ignited Engine
The objective of this study is to identify the trend of cyclic variation (CV) with respect to speed and load, to investigate its cause through simulation, and describe the ongoing efforts to set up and validate a simulation of the large bore natural gas engine used in the experiment. In an experimental study, in-cylinder pressure and equivalence ratio were captured as functions of speed and load. Cyclic variation was apparent at certain operating conditions. To diagnose the reason for this cyclic variation, a simulation was constructed. Experimental results of crank-angle resolved air manifold pressure, fuel pressure, and exhaust manifold pressure were provided to the simulation as boundary conditions. Numerical results showed considerable increase in agreement between simulated and measured stuffing box pressures and more stable predicted results of equivalence ratio. This, in a small way, demonstrates the nuanced and invaluable interaction between simulations and experiments.