A NOTE ON THE THERMAL CONDUCTIVITY OF SOLID NITROGEN AND THE DIRECT CONDENSATION OF NITROGEN GAS INTO A SOLID

摘要

In the U. S.C. low density tunnel designed to operate on the “two-phase” principle, nitrogen gas is used as the working medium. Downstream of the test section, the gas is condensed directly into a solid by exposing the gas to a refrigerated surface maintained at a constant temperature (in the range of 15 to 30°K). To estimate the condensation rate (i.e. , the mass of nitrogen condensed per unit time ) per unit area of the surface the problem is treated from the point of view of one-dimensional unsteady heat conduction through the growing layer of the solid condensate. An analytical solution of the problem is obtained.