1992 Volume 9 Issue 2 Pages 57-
An experimental study of the gravitational effects on the property of the thermal convection in vapor phase is performed utilizing the MU-300 airplane. This experiment is conducted as the preliminary study of SFU / EEFU /GDEF (Space Flyer Unit / Exposed Facility Flyer Unit / Gas Dynamics Experiment Facility) mission. The visualization of gas flow at low pressure shows that the thermal convection is immediately reduced in microgravity condition. The relaxation time of convection is estimated to 2 - 3 second. The fluctuation of temperature distribution of gas is observed only in microgravity condition. It is synchronized with the residual gravity (g-jitter) simultaneously measured in the airplane. This effect is enhanced in the region of low frequency, and it can not be observed in both 1 g and 2 g conditions. This phenomenon is interpreted by the order of magnitude analysis.