To study the dynamic characteristics of the cantilever turbopump rotor in rocket engines, finite element models of the rotor dynamic characteristics are established using 3D solid elements and 2D beam elements to conduct dynamic characteristic analysis. The sensitivity of the impeller and turbine to unbalance on the rotor is obtained. High speed dynamic balance tests of the rotor are conducted on a high-speed rotating tester, and the results show that the finite element model well reflects the true dynamic characteristics of the rotor, with a calculation error of no more than 5%. Compared with 2D beam element model, the calculation accuracy of the 3D solid elements model is higher. The rotor is most sensitive to the imbalance on the turbine, providing a theoretical reference for high-speed dynamic balancing test. After high-speed dynamic balancing, the amplitude reduction of the rotor at critical speed is not less than 70.27%, and the reduction of elastic support stress is not less than 84.38%, indicating good dynamic balancing effect. The research provides a reference for the analysis of the dynamic characteristics of the rotor of a large cantilever turbopump and high-speed dynamic balancing tests.

Aiming at the high temperature environment of the attitude control solenoid valve, the affected performance of the valve is simulated and analyzed. At the same time, the high temperature experiment of the valve is carried out. The results of simulation analysis and high temperature experiment indicate that the moving distance of the armature reduced due to the Non-metallic expansion of the core at high temperature, which causes the valve unable to open normally. And with the swelling effect of the oxidant to the core, the reliable operation temperature of oxidant valve is lower than fuel valve. By taking measures of enlarging the moving distance and replacing the core material to PFA, the high temperature environmental adaptability of the solenoid valve is improved.

In order to optimize the rational design of the thermal structure of solid rocket motor and accurately measure the erosion morphology of the insulation layer, a three-dimensional scanning technology is employed for this purpose. This study proposes a three-dimensional laser scanning strategy and a method for processing solid rocket motor three-dimensional data to analyze the wrapping characteristics of the insulation layer and cylindrical cylinder section of the shell. The proposed approach enables realization of three-dimensional data on erosion morphology in solid rocket motor insulation layers, facilitating determination of corresponding erosion amounts. Compared to traditional methods, this intelligent, comprehensive, and efficient method offers great application prospects for measuring erosion thickness in solid rocket motor insulation layers.

Torque limiter is a physical protection device that ensures mechanical equipment operates under safe load conditions. Conventional engineering design typically employs static design and verification methods, with optimization and iteration carried out through physical prototypes, resulting in long development cycles and high costs. The design simulation and combination parameter optimization of a miniaturized torque limiter for a specific model are focused on. Firstly, based on the principle and elements of the steel ball's inclined surface disengagement, some mathematical formulas are established and a three-dimensional structure is designed, identifying the key parameters affecting the performance of the torque limiter. Secondly, the torque transmission characteristics and structural strength of the torque limiter are simulated, and the accuracy of some strength simulation results is verified by using Hertz contact theory. Thirdly, the main structural parameters are optimized and evaluated by using the orthogonal experiment method, obtaining the best parameter combination. Finally, two principle prototypes are produced based on the models before and after optimization, and static disengagement experiments are conducted to verify the accuracy of the disengagement torque under static load.

High-speed centrifugal pumps are widely used in industry and aerospace, and their performance is affected by the matching of the number of inducer and impeller blades. In order to study the effect of different matching relationships on the pump performance, numerical simulations based on the RNG k-ε model are carried out using ANSYS-CFX software, and the accuracy of numerical calculations is verified by external characteristic tests. By analyzing six matching relationships of inducer blades with 3 and 4, and impeller blades with 5, 6, and 7, the results indicate that when the number of impeller blades is fixed, the head is improved at small flow rates but reduced at large flow rates while increasing the number of inducer blades. Keeping the number of inducer blades unchanged, the head is improved while increasing the number of impeller blades, especially at large flow rates. Increasing the number of inducer blades expands the range of vacuole distribution, while changing the number of impeller blades has less effect on cavitation performance.

Nuclear thermal rockets, as a revolutionary potential space luanch vehicle, have the capability to significantly reduce the scale of space transportation missions or enhance transportation capacity. The historical research of nuclear thermal propulsion (NTP) technology in the United States and Russia (The Soviet Union) is reviewed, the development challenges of nuclear thermal rocket are analysed. By proposing feasible lunar return missions and manned Mars exploration transportation tasks for nuclear thermal rocket, the study examines key technological challenges form an engineering application perspective, including optimization of overall parameters, high-power thermal propulsion, nuclear safety design and protection. At the end of the research, it is suggested to strengthen the research and development of key nuclear thermal rocket technologies and promote the construction of non nuclear and nuclear testing capabilities.

In response to the application background of satellites passing over or observing a ground target within a specific time, the Walker constellation scheme design is carried out for meeting the revisiting time requirements. The models of a satellite coveraging a ground target are constructed. The methods for calculating the time-windows of a satellite passing over a ground target, and onboard circle/rectangular-field-of-view sensor observing a ground target are designed. On this basis, a Walker constellation scheme design algorithm which satisfies the revisiting time requirement with the minimum satellite number is developed. The simulations and analyses are provided for three simulation scenarios. The results of the developed algorithm are compared with STK, and the average error of revisiting times is less than 1.1 s, which verifies the accuracy and rationality of the models and the algorithm. The relevant research results can provide reference for the design of Earth observation constellation schemes.

The gas-liquid combined rapid erection hydraulic system is a new type of large flow hydraulic system which is driven by gas and motor pump, and can greatly increase the erection speed. The fault analysis and the reliability analysis of a rigid erecting hydraulic system with combined gas-liquid oil is carried out. Then the fault tree analysis is carried out by taking the fault of excessive vibration in the erection position as an example. The simulation analysis of typical faults of the system is carried out by means of co-simulation, and the relationship between fault causes and fault phenomena is studied and the effects and hazards of the fault are discovered. Some improvement measures are put forward to improve the reliability of the system.

For the aerodynamic and overall optimization of hypersonic glide vehicles, this study proposes a performance evaluation method grounded in exergy theory. A multidisciplinary exergy dissipation model is developed, integrating aerodynamics, thermal protection, control, structures, and trajectory. This framework consolidates diverse metrics—such as aerodynamic efficiency, stability, and maneuverability—into a single, physically meaningful exergy loss parameter, enabling quantitative trade-off analysis. Using an HTV-2-like lifting-body configuration, aerodynamic optimization is performed with the objective of minimizing exergy loss, and its differences from lift-to-drag ratio optimization are examined. Based on the exergy balance equation, the potential applications of exergy loss analysis in conceptual design are discussed. The results indicate that this approach can rapidly identify performance bottlenecks, support multidisciplinary design optimization, and offer a new theoretical tool and evaluation paradigm for hypersonic vehicle design.

The gauging accuracy of propellant filling system is critical to the success of aerospace launch. Because of the defects of the calibration method for the flowmeter of launch site filling system, the deviation for the liquid level I value calculated by the filling system flowmeter and the theoretical value of the rocket tank liquid level I is quite large. An online calibration method is proposed for the flowmeter of filling system by which K coefficient of flowmeter is corrected by the rocket tank liquid level I. The result is shown that gauging accuracy of propellant filling system in launch site is enhanced, which is of great importance for the success of rocket launch.