Submission
Numerical Analysis of the Transient Compressible Fluid Flow in the Piston-Cylinder Clearance of an Oil-Free Linear Compressor
DOI: 10.18462/iir.compr.2021.0371
Session: Reciprocating compressors 2
Accept state: Submission accepted
Authors
| Name | Organization | |
|---|---|---|
| Thiago Dutra, Ph.D. | Federal University of Santa Catarina | |
| Claudio J Santos, M.Sc. | Federal University of Santa Catarina | |
| Cesar J Deschamps, Ph.D. | Federal University of Santa Catarina |
Abstract
Oil-free linear compressors adopt aerostatic bearings to avoid metal contact between the piston and cylinder. Despite the small friction in the bearing, the gas flow in the piston-cylinder clearance can generate losses that decrease the compressor efficiency. The present paper reports a model developed to evaluate such losses and their effects on the volumetric and isentropic efficiencies. The transient compressible fluid flow in the gap is simulated with a commercial code based on the finite volume method, whereas the compression cycle in the cylinder is solved with an in-house code using a lumped model formulation. The model was employed to assess the compressor performance as a function of four parameters: compressor speed, piston oscillation amplitude, pressure ratio and radial clearance, It was found that the compressor efficiency is mainly reduced when the clearance dimension and pressure ratio are increased.
Keywords
Linear Compressor
Clearance
Leakage