The phenomenon of unsteady condensation of moist air was studied in an ideal two-dimensional oscillation tube model-shock tube model with numerical method.The computational results were compared with the previous experimental data.The results obtained showed that the field structure and parameters changed dramatically with the interaction of condensation shock and flow field.Condensation occurred in the tail of expansion wave.The jump of temperature and pressure was more sensitive to the growth stage of drops than to the initial stage of nucleation.The space distribution of nucleation changed with time and gradually expanded.The rise of nucleation rate at the initial stage was larger than the drop of nucleation rate after the nucleation peak.Furthermore

the nucleation intensity

the space of nucleation and the location of its occurrence changed with the initial relative humidity and pressure ratio.