A numerical model was built to investigate the dynamic performance of the liquid nitrogen supplying system in the 0.3 m cryogenic wind tunnel. Based on one-dimensional thermal fluid analysis

the model was used to analyze heat leakage

level of the accumulator

two-phase flow and injection pressure. Combining the numerical model with control strategy and experiments

the dynamic pressure analysis for the injection rake was achieved. It showed that the relative error between numerical results and experimental data was below 10%. During experimental validation

the interference of the four regulating valves was avoided with universalization of the nominal working pressure of injection nozzles and convergence of pipes after these valves. The second recirculation pipe above the injection rake was used to eliminate the two-phase flow phenomenon of the terminal of the system

helping to make the control accuracy reach 1.1%

and adjust time to 23 s. With the numerical studies and reconstruction of the pipes and nozzles

the liquid nitrogen supplying system is able to meet the requirement of the total temperature control of the wind tunnel.