One Dimensional Numerical Solution of Pulsating Flow in a Pulse Tube Cycle Considering Real Gas Behavior

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Roshanghalb, Farid | 2010

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Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 40954 (08)
University: Sharif University of Technology
Department: Mechanical Engineering
Advisor(s): Saidi, Mohammad Hassan; Kazemzade Hannani, Siamak
Abstract:
Helium gas is the working fluid in common Pulse Tube Refrigerators (PTRs) due to its brilliant properties in reaching cryogenics temperature as low as 4 K. Generally ideal gas equation of state has been used to evaluate thermodynamic performance of He. However using ideal gas equation of state for He in 10 bar and 5 K causes considerable error on estimation of density. The objective is to use real gas equation of state for temperatures near zero Kelvin. This approach makes an accurate prediction of PT cooling capacity and COP. In this thesis the objective is to realize the most relevant equations of state describing the proper behavior of He in the regions of operating point of PTR. Later on the equations have been implemented in governing equation of different section of PTR in order to model one dimensional and non steady helium flow in a double inlet PT orifice type. These equations have been solved numerically using a developed CFD code with Finite Volume approach. Finally cryocooler operating parameters will be obtained and compared with results of ideal gas equation of state.
Keywords:
Finite Volume Method ; Pulse Tube Refrigrator ; Helium Gas ; State Equation ; Real Gases

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