Ejector, Oscillating nozzle, Entrainment Ratio, VJRS
The demand for cooling increases at faster rate than the energy availability. So, refrigeration systems that use renewable energy sources need to be developed to reduce energy demand thus addressing the energy crisis and environmental pollution related to this. An ejector based refrigerator is one kind of a system which uses thermal energy sources such as solar energy, waste heat from industry, automotive exhaust, etc. to operate the system. Ejector consists of a primary driving nozzle, mixing section, and diffuser. Ejector is used to pump the refrigerant from evaporator to condenser using high pressure stream. Thus replacing compressor present in the conventional refrigeration system. Present study numerically investigates the effect of oscillation of convergent-divergent nozzle in an ejector using ANSYS Fluent.15.5. The nozzle domain will oscillate between two points in the ejector at particular frequency and amplitude. The motion of nozzle and movement of the mesh according to the nozzle oscillation is made possible by user-defined functions available in ANSYS Fluent 15.5. Variation of entrainment ratio with time has been studied at different amplitudes and frequency combination and the same is compared with the stationary nozzle. Even though the oscillating nozzle underperforms the conventional one at lower amplitude and frequency, the former one shows a trend of increasing with increasing frequency. References Selvaraju, A. Mani, Analysis of an ejector with environment-friendly refrigerants, Appl. Therm. Eng., Vol. 24, (2004). Y. Bartosiewicz, Z. Aidoun, P. Desevaux and Y. Mercadier, Numerical and experimental investigations on supersonic ejectors, Int. J. Heat Fluid Flow, Vol. 26, (2005). Arun K.M., S Tiwari and A. Mani, Three-dimensional numerical investigations on rectangular cross-section ejector. International J. Thermal Sciences, Vol. 122 (2017).