Abstract
Visualization of gas fl.ow in a thermal chemical vapor deposition (CVD) furnace under microgravity (µg) has been studied. The sample gas of the experiment is N2 or He and gas pressure is 500 Torr. For visualization, tracer particles (Ti02) are injected into the thermal CVD furnace with the sample gas. In order to explain the tracer pattern, numerical simulation is performed employing a finite volume method. The results showed that N2 gas flow under µg is the forced convection without the natural convection. This result agrees with the numerical simulation. The He gas flow under µg is quite diffrent from the numerical simulation. It is considered that notable thermophoretic transport of the tracer particles occurs, because the He gas has high thermal conductivity which realizes large thermal gradient in entire fluid path.
