Affiliation:
1. Indian Institute of Science Department of Mechanical Engineering Bangalore, India
Abstract
The pressure-time characteristics for the charging process of a cylinder with a piston-controlled port through a connecting duct is studied with the objective of assessing the accuracy of various methods such as the lumped parameter or zero-dimensional approach, an intermediate hybrid approach and a full three-dimensional computational fluid dynamics (CFD) calculation. The predictions from all the approaches are compared with experimental data. It is observed that, for a particular cup-shaped geometry of the piston, both the zero-dimensional and hybrid approach overpredict the pressure recovery rate in comparison with the three-dimensional CFD calculation, which is in good agreement with the experimental pressure-time variation. On the other hand, the agreement between the lumped parameter approach and the detailed CFD calculation is better for a flat piston, indicating the importance of the piston geometry.