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Theses
Etudes théoriques et expérimentales de caloducs et de thermosiphons soumis à de fortes accélérations
Etudes théoriques et expérimentales de caloducs et de thermosiphons soumis à de fortes accélérations
Abstract : One could consider heat pipe as a passive heat transfer componant with a very high thermal conductivity from about 100 to 1000 time the copper conductivity. Wide ranges of use are presented though examples of applications. Heat pipe physical principle is based on phase change heat capacity and closed cycle of saturated fluid flow. We proposed a detailled classification of heat pipes which allows us to restrict our detailled presentation of physical phenomenon into heat pipes. This these deals with circular heat pipes, with or without capillary structures, under very low, terrrestrial or high acceleration field.
Heat transfer limits are presented though a wide litterature survey. Some new assumptions lead to a more physical calculation of the sonic limit.
Moreover, as heat transfer conductances are very important to design a heat pipe, we have sudied many publications to present a survey of knowledge. For a wide range of heat pipes, we deals about the more accurate way to calculate conductances by examining internal physics phenomenon into heat pipes. This leads to modeling heat transfer in thin film taking into account phase change conductance and disjoining pressure concept.
To improve understanding of heat pipe behavior, we developed an experimental equipment which allows testing of heat pipe under artificial acceleration field up to 90 m s-2 at an adiabatique temperature from 0°C to 100°C and for power input up to 1400 W.
Many parametters like adiabatic temperature, power supply, heat flux density, acceleration field (direction and intensity), fluid, wall material, dimensions and capillary structure are explored. Some experimentals resultts are in accordance with our expectations, but many behaviors are unexplained yet, but allows us to direct future research in field which could improve global model or correlations of heat pipe behaviors.
Heat transfer limits are presented though a wide litterature survey. Some new assumptions lead to a more physical calculation of the sonic limit.
Moreover, as heat transfer conductances are very important to design a heat pipe, we have sudied many publications to present a survey of knowledge. For a wide range of heat pipes, we deals about the more accurate way to calculate conductances by examining internal physics phenomenon into heat pipes. This leads to modeling heat transfer in thin film taking into account phase change conductance and disjoining pressure concept.
To improve understanding of heat pipe behavior, we developed an experimental equipment which allows testing of heat pipe under artificial acceleration field up to 90 m s-2 at an adiabatique temperature from 0°C to 100°C and for power input up to 1400 W.
Many parametters like adiabatic temperature, power supply, heat flux density, acceleration field (direction and intensity), fluid, wall material, dimensions and capillary structure are explored. Some experimentals resultts are in accordance with our expectations, but many behaviors are unexplained yet, but allows us to direct future research in field which could improve global model or correlations of heat pipe behaviors.
https://tel.archives-ouvertes.fr/tel-00130174
Contributor : Cyril Romestant <>
Submitted on : Friday, February 9, 2007 - 3:37:40 PM
Last modification on : Tuesday, September 1, 2020 - 4:00:07 PM
Long-term archiving on: : Tuesday, April 6, 2010 - 8:40:11 PM
Contributor : Cyril Romestant <>
Submitted on : Friday, February 9, 2007 - 3:37:40 PM
Last modification on : Tuesday, September 1, 2020 - 4:00:07 PM
Long-term archiving on: : Tuesday, April 6, 2010 - 8:40:11 PM