Elastic Distortion Calculation of a Controlled-Clearance Piston-Cylinder Assembly up to 1500 MPa Using Finite Element Method. Issue 1 (1st April 2022) - Liu, Chunguang
Abstract: A controlled-clearance piston-cylinder assembly is modelled using finite element method (FEM). Elastic distortion of the piston-cylinder engagement gap is calculated by the FEM model and then is input to a fluid dynamics model to solving the pressure distribution which works as load in the FEM model. Accurate distortion-pressure solutions are obtained for measurement pressure of (100~1500) MPa by iterative calculations until a convergence of interest is reached. Results are generated for various jacket pressures maintaining balance. Dramatic rapid decent are found near the gap exit after a steady profile for both distortion and pressure distribution curves. Gap exit width can be two orders of magnitude smaller than the nominal gap clearance, and comparable to the irregularity of the piston and cylinder, introducing risks of inaccuracy or potential damage.