ISSN Online: 2377-424X
ISBN Print: 0-89116-299-2
International Heat Transfer Conference 7
EFFECTS OF MOLECULAR VIBRATIONAL RELAXATION ON STAGNATION HEAT TRANSFER
Resumo
In effective utilizations of moderate temperature heats such as hot brine, OTEC, waste heats and cold of LNG, the Rankine cycle using multi-atomic molecules such as hydrocarbons or freons is adequate to electric power generation. Some multiatomic molecules such as C02 have comparatively large molecular vibrational relaxation time. This paper makes a theoretical and experimental study on stagnation heat transfer as a means of conducting further research in the effects of vibrational relaxation time on thermo-fluid phenomena. In the experimental study, a glass cylinder of 2 mm diameter having a thin platinum film near the stagnation point was set in a shock tube. From a felicitous agreement between theory and experiment, it is concluded that when the relaxation time is equal or
longer than the flow characteristic time, the heat
flux is smaller than that in the thermal equilibrium
case, and that the heat flux decrease caused by
the relaxation gets larger with high contribution
of vibrational degree to specific heat.