A first experimental attempt has been realized in order to measure the heat transfer between a heated platinum wire having a diameter (d) of 0.15 mm, disposed along the axis of a cylindrical shell in stainless steel having an inner diameter (D) of 100 mm, and air from atmospheric conditions down to 10-3 mbar. Temperature differences between the wire and the external stainless steel cylindrical shell in the range of 50-125 K were imposed and the heat power transferred from the wire to the surround was measured as a function of the gas pressure. The experimental results demonstrates that for an accurate measurement of the heat conduction when the pressure goes down to 0.05 mbar is very important to be able to quantify accurately the radiative contribution which becomes predominant at low pressure. The main limitations of the test rig described in this paper have been analysed in order to highlight the modifications which can be suggested to obtain experimental results comparable with theoretical models.
Chalabi H., Saraceno L., Boccardi G., Celata G. P., Lorenzini M., Morini G. L. (2012). Experimental analysis of heat transfer in a high diameter ratio annular gap filled with a rarefied gas. JOURNAL OF PHYSICS. CONFERENCE SERIES, 395, 1-9 [10.1088/1742-6596/395/1/012020].
Experimental analysis of heat transfer in a high diameter ratio annular gap filled with a rarefied gas
LORENZINI, MARCO;MORINI, GIAN LUCA
2012
Abstract
A first experimental attempt has been realized in order to measure the heat transfer between a heated platinum wire having a diameter (d) of 0.15 mm, disposed along the axis of a cylindrical shell in stainless steel having an inner diameter (D) of 100 mm, and air from atmospheric conditions down to 10-3 mbar. Temperature differences between the wire and the external stainless steel cylindrical shell in the range of 50-125 K were imposed and the heat power transferred from the wire to the surround was measured as a function of the gas pressure. The experimental results demonstrates that for an accurate measurement of the heat conduction when the pressure goes down to 0.05 mbar is very important to be able to quantify accurately the radiative contribution which becomes predominant at low pressure. The main limitations of the test rig described in this paper have been analysed in order to highlight the modifications which can be suggested to obtain experimental results comparable with theoretical models.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
