Development and validation of an analytical model for perforated (multi-stage) regenerative M-cycle air cooler

Maisotsenko cycle based coolers are able to reduce the air temperature below the wet-bulb temperature of the inlet air without adding any moisture to the product air and without the use of any compressor or refrigerant (CFC). These positive features of M-cycle have encouraged the researchers to enthusiastically consider the thermal-fluid characteristics of M-cycle cooler via numerical, analytical and experimental techniques. In this paper attempts are made to present an analytical solution for thermal behavior of perforated (multi-stage) regenerative M-cycle exchanger which has not been carried out before. Indeed, all previous analytical solutions of M-cycle have been provided for the simplest structure of M-cycle exchanger (single-stage, without perforation) and the perforated M-cycle cooler (multi-stage) has been investigated only via experimental and numerical techniques (including finite difference method, numerical epsilon-NTU technique, statistical design tools all of which are sophisticated and require high computational time). However, the precision aspect and analysis speed of analytical approach is undeniable and it is considered as the priority in most engineering problems. Hence, in this study, an analytical model is developed for three-stage regenerative M-cycle exchanger which can be developed for any number of perforations. All modeling process is described in detail (step by step) to make it ease understanding for readers. Evaluation methods of all required parameters are described in detail as well. Finally, the model is verified with numerical results.