Year : 2012, Volume : 37, Issue : 1to4
First page : ( 140) Last page : ( 145)
Print ISSN : 0379-0479. Online ISSN : 2349-2120. Published online : 2012  3.

Phase angle and flow pattern studies for inertance tube puise tube refrigerator

Hatwar Rajeev¹, Atrey M.D.¹

¹Mechanical Engineering Department, Indian Institute of Technology Bombay, Powai, Mumbai-400076

Abstract

The phase angle between mass flow rate and pressure and the flow patterns in a Pulse Tube Refrigerator (PTR) are important factors which affect the performance of the refrigerator. Various modifications have been made to the PTR in order to reduce the phase angle and secondary flow, to increase the refrigeration effect. Secondary flow emerges due to the change in the cross-section and the direction of the flow. Flow straighteners and tapered pipes are used to avoid the formation of secondary flows. These secondary flows disturb the temperature profile in PTR, which in turn deteriorate the refrigeration effect.

The present paper highlights the emergence of secondary flow in Inertance Tube Pulse Tube Refrigerator, especially near the cold end heat exchanger, and correlates it with the phase difference. The analysis further studies the effect of change in crosssection area on secondary flow and its effect on the performance of the PTR. The modelling of the ITPTR is done using commercial CFD software, FLUENT 6.2. From the analysis, it has been observed that, the phase difference between the mass flow rate and the pressure is responsible for the secondary flow. The duration of secondary flow per cycle is directly proportional to the phase difference. Hence reduction in the phase difference amounts to reduction in secondary flow.

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Keywords

Inertance Tube Pulse Tube Refrigerator, CFD, Flow Pattern, Secondary Flows.

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