Accession Number : AD0608161

Title :   CONDENSATION OF CARBON DIOXIDE IN SUPERSONIC NOZZLES,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE GAS TURBINE LAB

Personal Author(s) : Duff,Karl M.

Report Date : SEP 1964

Pagination or Media Count : 54

Abstract : Test results indicate a definite region of supersaturation of CO2 prior to its expansion. In Curve I, using assumed isentropic temperatures based on measured pressure ratio, the supersaturation ratio (ratio of static pressure to flat-surface equilibrium pressure at local temperature) obtains an estimated value of 9.14, prior to condensation occurring. In Curve 3, the supersaturation ratio reaches a value of 10.5 prior to condensation and in Curves 4, 5 and 7 values of 11.6, 13.4 and 16.8, respectively. The fact that supersaturation ratios steadily increase prior to the occurence of rapid condensation tends to support the predicitions of nucleation theory that, for CO2, the lines of constant nucleation rate diverge with decreasing pressure and temperatures and that nucleation rates have a critical value of the ratio between the static and stagnation pressures beyond which they rise astronomically, creating a narrow zone where the large portion of condensation occurs. It is further concluded that the interferometer does not lend itself to the convenient procurement of accurate density and pressure profiles in this particular nozzle under these extreme temperature conditions.

Descriptors :   (*CARBON DIOXIDE, CONDENSATION), (*SUPERSONIC NOZZLES, CONDENSATION), (*SPACE PROPULSION, CONDENSATION), GAS FLOW, NUCLEATION, INTERFEROMETERS, STAGNATION POINT

Distribution Statement : APPROVED FOR PUBLIC RELEASE