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A N AIR - POLYMER ANALOGY FOR MODELING AIR
FLOW THROUGH RUBBER - METAL INTERFACE –
T ECHNICAL NOTE by GILAD PAGI , ELI ALTUS
T ECH NICAL R EPORT ETR-2007-02
July 2007
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TECHNION — Israel Institute of Technology, Faculty of Mechanical Engineering
An air-polymer analogy for modeling air flow through rubber-metal interface – Technical note
GILAD PAGI, ELI ALTUS
Faculty of Mechanical engineering
Technion – Israel Institute of Technology
Haifa, 32000
ISRAEL
gilad@tx.technion.ac.il
Abstract: - This note compliments the technical part of the paper with the title, which will be presented in the
WSEAS FMA’07 conference. This note presents the mechanical design of the system in question and more experimental findings which support the assumption of the novel model constructed there. Moreover, this note contains first conclusions and preliminary discussions.
A system composed of a metallic cylinder filled with pressured air (up to 5 atm), and a rubber, square sectioned ring, as a seal was investigated theoretically and experimentally. Under a certain pressure difference (internal minus atmosphere pressure - p) and external sealing force, the rubber seal is compressed
(h) and should prevent air leakage. However, experiments show a continuous, nonlinear decrease in p(t) as a function of time. A few classical (macro) thermodynamic models for predicting p(t), via considering air flow through cracks, have been suggested before, based on [1] but they have failed to describe the profile in question due to the coupled constitutive properties of rubber and a construction that allow the creation of micro-scale "tunnels" in the rubber-lid interface, through which the air can pass. A novel heuristic model, which assumes a symmetry preserving analogy between the micro-scale air tunnels and the rubber polymer strands is proposed. Thus, polymer equations based on statistical thermodynamics are
FLOW THROUGH RUBBER - METAL INTERFACE –
T ECHNICAL NOTE by GILAD PAGI , ELI ALTUS
T ECH NICAL R EPORT ETR-2007-02
July 2007
³©¤§ ³ª©¥ ¡¥° ¥±²¢¥ ¢¥©¤¡ ¨¤§ » ¨¢©¤¡
TECHNION — Israel Institute of Technology, Faculty of Mechanical Engineering
An air-polymer analogy for modeling air flow through rubber-metal interface – Technical note
GILAD PAGI, ELI ALTUS
Faculty of Mechanical engineering
Technion – Israel Institute of Technology
Haifa, 32000
ISRAEL
gilad@tx.technion.ac.il
Abstract: - This note compliments the technical part of the paper with the title, which will be presented in the
WSEAS FMA’07 conference. This note presents the mechanical design of the system in question and more experimental findings which support the assumption of the novel model constructed there. Moreover, this note contains first conclusions and preliminary discussions.
A system composed of a metallic cylinder filled with pressured air (up to 5 atm), and a rubber, square sectioned ring, as a seal was investigated theoretically and experimentally. Under a certain pressure difference (internal minus atmosphere pressure - p) and external sealing force, the rubber seal is compressed
(h) and should prevent air leakage. However, experiments show a continuous, nonlinear decrease in p(t) as a function of time. A few classical (macro) thermodynamic models for predicting p(t), via considering air flow through cracks, have been suggested before, based on [1] but they have failed to describe the profile in question due to the coupled constitutive properties of rubber and a construction that allow the creation of micro-scale "tunnels" in the rubber-lid interface, through which the air can pass. A novel heuristic model, which assumes a symmetry preserving analogy between the micro-scale air tunnels and the rubber polymer strands is proposed. Thus, polymer equations based on statistical thermodynamics are
References: matrix regenerators, International Journal of Heat and Mass Transfer, No.48, 2005, pp cracks, International Journal of Pressure Vessels and Piping, No.82, 2005, pp No.26, 2003, pp. 1069-1079, 2003. [4] B. Erman, J.E. Mark, Structures and Properties of Rubberlike Networks, Oxford, 1997 Polymer Networks, Macromolecules, No. 36, 2003, pp