Numerical Study of Unsteady Flows in a Scroll Compressor

Since scroll compressors contain gas pockets whose shapes and sizes change continuously, the flow fields inside the compressors are time dependent and three-dimensional. The spatial and temporal variations inside the gas pockets also induce unsteady flows between the gas pockets. This unsteadiness controls the mechanisms responsible for the behavior of the scroll compressor components and their interactions. The dynamic nature inherent in the scroll compressors affects the performance and reliability of the scroll compressors. To improve and optimize the scroll compressor design for better performance and reliability, information is needed to understand the detailed physics of the unsteady flows inside the scroll compressors. To provide the fundamental information needed, the unsteady flows in a scroll compressor are studied numerically. The system simulated includes upper bearing housing, scrolls, check valve, and discharge plenum. Refrigerant-22 is used as the working fluid. The unsteady flows inside and between the gas pockets are characterized by the instantaneous distributions of field quantities and the area- and mass-averaged parameters.