Hermetic compressor, suction muffler, computational fluid dynamics, acoustics, experimental pressure and temperature values
In this study, detailed temperature and pressure measurements were performed at the inlet, outlet and outer boundaries of the suction muffler of a hermetic reciprocating compressor. The measurements were conducted without effecting real phenomena. After experimental studies, detailed computational fluid dynamic analysis of the refrigerant flow (isobutane) in the suction muffler was performed. Experimental pressure and temperature values at the inlet, outlet and outer boundaries of the suction muffler were used as boundary conditions. The effect of suction valve (opening and closing) at the exit of the suction muffler has been considered. 3- dimensional time dependent calculations were completed when statistically steady state convergence was reached for one crank period. Realizable k-є turbulence model with appropriate parameters, second order discretizations for time and space derivatives and real gas model for isobutane (R600a) were applied for the numerical analysis. Mesh dependency of the analysis and solver algorithms were also investigated. The results of the numerical analysis has shown that the time integrated average of the numerically calculated mass flow rate is close to average mass flow rate measured with a calorimeter test system. Furthermore thermal mapping inside the suction muffler shows good agreement with experimental results. Time dependent flow analysis results inside the suction muffler help to characterize the flow and acoustic function of the muffler which leads to the new and better muffler designs.