There are many capacitive loads in airborne equipment, the safety and stability of power supply are negatively affected by the surge at the moment of switch closing of power distribution facility. The causes and hazards of surge are analyzed, and the scheme of surge restrain is introduced. The parameters of transistor scheme are studied. The experiments of high and low ambient temperature and wide input voltage range are carried out, simulated and tested to verify the function and effectiveness of the design.

For multi-axle vehicle which use integrated design and integral body structure, rigid-flexible coupling virtual prototype model is established, which analyzes ride comfort of distributed driving multi-axle vehicle. On base of different connective with cab and body and different cab structure, ride comfort of vehicle is given with different load and different run case. Root mean square value of vibration acceleration of the truss structure cab with inclined support is effectively reduced. Comfort of the cab with no-connectivity top structure is better. Through optimize cab's structure form and top link shape, ride comfort of vehicle improves better on case of empty-load and full-load, which can satisfy the demands.

Focusing on the main working phase of liquid rocket engine, with the aid of multivariate non-linear time series analysis, and based on Dual Stage Attention Based Recurrent Neural Networks (DA-RNN), a new time series analysis tool, Convolutional Dual Stage Attention Based Recurrent Neural Networks (CDA-RNN), is proposed, by which a fault trend prediction model is established. Compared with LSTM, DA-RNN, etc, this model shows higher prediction accuracy. Combined with autocorrelation analysis of the prediction residual, a quantitative basis of fault detection is proposed after introducing failure confidence probability. Using hot test data with weak fault to validate the model, result shows that the CDA-RNN model enables robust weak fault muti-parameter detection in unsteady working process. This strategy is so effective that it calls for direct engineering application.

A product-oriented virtual test framework for structural strength of aircraft bodies is proposed, under which the classical elastic-plastic damage constitutive of materials and general finite element technology are developed, and a human-computer interactive virtual test platform for aircraft cabin structure is created based on the virtual test plug-in tool developed by Abaqus built-in Python software. Using the accurate confirmation technology of step-by-step inspection, the virtual/real test comparison from the specimen to the complex cabin is carried out to verify the feasibility of the virtual test of the cabin structure. The results show that the virtual test can simulate the load-bearing failure of the cabin structure with high fidelity, and the prediction accuracy of the ultimate load-bearing capacity is 4.6%.

The hanging process is one of the key links in the Mid-Air retrieval of launch vehicle. According to the whole process of the launch vehicle tail cabin hanging in the air, the design of the hanging device based on the helicopter as the recovery platform is carried out. The hanging device includes tension sensor, load shedding device, overload protection device and the actuator in the end of the hanging device. Parafoil and parachute eject from the bottom of the tail cabin of launch vehicle. The hanging device can realize the hanging operation of the retrieval by hanging attached apex drogue on the top of parafoil. Through the simulation analysis of the hanging process, it can be seen that when the weight of the retrieval increases, the overload increases significantly. When the parachute retraction time increases, the load reduction effect is obvious

In radar countermeasures, the jammer detects the radar signal, then the signal is sampled by AD and input to FPGA for processing and generating interference signal. When using the FFT IP core officially provided by the FPGA platform Xilinx to perform FFT processing on the data output by the high-speed ADC, data preprocessing of "parallel-serial" is required, which greatly slows down the FFT processing speed. At the same time, the internal resources of FPGA is not maximized. An data processing method based on FPGA input block remapping is proposed. This method uses the data input remapping module to optimize the input data into a parallel block data stream format. Then the FFT butterfly networks process the input data into blocks to obtain the discrete Fourier transform data. Finally, parallel data are output. Experimental results show that this method can effectively save FPGA computing time, improve radar data processing speed, optimize the utilization of FPGA internal resources, and has the characteristics of good real-time performance and high flexibility.

The flow field simulation and scanning electron microscope observation methods are used to analyze the surface micromorphology of a certain type of turbine blade before and after operation, and the effect of high temperature and high pressure environment on the surface morphology of the blade is investigated. First, in order to improve the calculation efficiency, according to the blade form, a periodic symmetric CFD model of the turbine blade flow field is established, and the temperature and pressure of the flow field are calculated and analyzed by the finite volume method. Then, the surface of the working blade is measured by scanning electron microscope. The morphology is observed to analyze the form of micro-defects on the blade surface. Finally, based on the results of simulation and experimental observations, the reasons for the blade defects and the factors affecting the changes of the blade surface microstructure are analyzed. The results show that the temperature of the leading edge of the blade reaches the highest ${860}\mathrm{\;K}$. Under the combined effect of geometric structure and wave system, the flow characteristics of the flow field near the leading and trailing edge, blade tip, and hub are complicated, and the temperature and pressure distribution in the flow channel is inhomogeneous. The hub near the trailing edge of the blade appears with a cross-grain/inter-grain mixed mode of microcracks about ${180\mu }\mathrm{m}$ in length, and an inclusion crack with a length of about ${30\mu }\mathrm{m}$ appears at the tip of the trailing edge. This is due to the thermal stress of the blade, the metallographic transformation of the blade surface, and the oxidation, hydrogen embrittlement and other effects. According to the actual task of the turbopump, the turbopump ground hot test program should be reasonably arranged, especially in the shutdown stage, consider whether to take atmospheric environmental isolation measures for the cooling of the turbine blades. The current work can provide a reference for the life evaluation of liquid rocket engine turbine blades.

In order to timely and accurately understand the development trend of world aerospace field in 2023, the latest developments in world space transportation system, ballistic missile and hypersonic technology are comprehensively reviewed, involving key model research and development, flight tests and major hot events in the aerospace field of the United States, Russia and other countries. The development of world aerospace field in 2024 is forecasted by summarizing and analyzing.

Based on the huge requirement of LEO or MEO business satellite launch mission, responsive launch technology for large or middle launch vehicle is badly needed. According to the requirements of Long March-8, land-launched supporting system focus on horizontal assembly and erection technology, responsive and intelligent launch technology, which can improve the efficiency of launch mission, simplify the equipment of launch site, and save launch cost. The study mainly elaborates horizontal assembly equipment, erection equipment, intelligent gas supply system. Two horizontal assembly schemes of spreader and bracket car are introduced. The factors that affect the accuracy of erecting and butting of the whole transport are analyzed, and the method of raising the rigidity of the erecting bracket are given. The general scheme of intelligent gas supply and distribution, intelligent pressure reducing valve technology and fault diagnosis technology of gas supply and distribution equipment are introduced.

The matching design of thrust and drag is the core issue in the design of air-breathing vehicles. In order to obtain the drag trait of the inlet and reduce the interior drag, and then improve the overall performance of the air-breathing vehicles, a study on the cold-flow drag trait of a supersonic, twin-duct inlet is conducted with a CFD method. By comparing the flow characteristics and drag trait of the inlets with different length, turning angle, divergence ratio of the curved ducts, drag allocation proportion of different parts of the inlet is acquired and effects of the geometric parameters on the flow structure and drag are attained. Results indicate that a flow separation will probably generate in the curved duct of a twin-duct inlet at a cold-flow condition, which results in a large loss of the flow. It is noted that the drag of the curved duct accounts for majority of the entire inlet when there is no spilled flow. The drag of the curved duct can be reduced by decreasing the turning angle or increasing the divergence ratio of the curved duct. However, due to the interrelationship between the curved ducts' length and turning radius, the drag of the curved duct firstly reduces and then turns to rising with the increment of the curved ducts' length at a fixed design condition.