Adapter separation is a critical phase during the launch tube ejection process of cold-launch missiles. Its operational state influences relative positional relationships between adapter groups, as well as between adapters and the missile itself, directly impacting launch safety. Despite its importance, systematic studies on modeling the separation process and quantifying its states remain underdeveloped. This study aims to investigate the separation time and velocity of the adapter by adopting a method that combines numerical calculation, dynamic simulation, and experimental data comparison to analyze the separation process and force conditions. By establishing theoretical models for the separation process, the Runge-Kutta numerical algorithm is applied to derive solutions for separation time and lateral velocity. Dynamic simulations are further conducted to replicate the separation behavior, while experimental data analysis interpreting real-world conditions. Results demonstrate strong agreement between numerically calculated separation times/lateral velocities, simulation outputs, and experimental measurements, validating the feasibility of theoretical framework. Building on this foundation, the effects of critical parameters are explored—including angle of attack, lateral wind speed, and initial installation force of the pin assembly spring—on separation time and lateral velocity. Key influencing factors are identified, providing actionable insights for optimizing adapter design in cold-launch systems.

High-accuracy core loss models are an essential foundation for loss evaluation and efficiency optimization in servo power converters. A PWM excitation core loss model is proposed based on the DC power method to address the issue of large errors in core loss evaluation under PWM excitation using the Modified Steinmetz Equation (MSE) in traditional methods. This method directly establishes a loss model based on the measurement results of magnetic core loss under PWM excitation obtained by the DC power method, which can avoid the errors introduced by the MSE model in the waveform equivalent transformation stage and has better model accuracy. The experimental results show that the maximum relative error of the proposed model for loss evaluation under different excitation waveforms, frequencies, duty cycles, peak AC magnetic flux densities, and temperatures is -5.029%. The average absolute value of the relative error is only 1.72%, much lower than the model error of MSE (maximum relative error: 87.663%, average absolute value of relative error: 38.04%). It verifies the accuracy of the PWM excitation core loss model proposed under a wide range of operating conditions and can provide a high-precision calculation model for loss evaluation of power converter magnetic components under PWM excitation.

To study the breakup atomization and development process of kerosene propellant in crossflow under subsonic conditions, and to realize the accurate numerical simulation of fuel atomization, a kerosene jet in crossflow with average flux-to-momentum ratio q ranging from 7.9 to 46, and average We_g ranging from 5.6 to 120 is selected to enter the mainstream of the air under the velocity conditions of 11 subsonic uniformly incoming air main streams and the phenomenon of primary atomization under the action of crossflow is investigated by the Volume of FluidMethod and Adaptive Mesh Refinement method. The volume of the FluidMethod (VFM) method and Adaptive Mesh Refinement (AMR) method are used to investigate the primary atomization phenomenon under the jet's action in crossflow and verify the accuracy of the numerical simulation method by comparing it with the experimental results. The results show that jet fragmentation of kerosene propellant is mainly caused by surface tension, especially the Rayleigh-Taylor (R-T) instability plays a dominant role. In contrast, the surface fragmentation triggered by the Kelvin-Helmholtz (K-H) stability precedes the liquid column fragmentation caused by the R-T instability. The atomization process is negatively correlated with the mean gas Weber number, positively correlated with and strongly influenced by the mean flux-to-momentum ratio q, and finally an empirical equation for the jet penetration depth profile suitable for atomization in crossflow jet is obtained.

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.

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.

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.

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.

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.