Aimed at the bearing dynamic load vibration response and optimal design of a complex rotor system with inter-shaft bearing in a turbofan engine with high thrust-to-weight ratio, a mechanical model of bearing dynamic loads is established to study the effects of unbalance, bending deformation and iner...

In order to control the deformation of rotor and distribution of multiple critical speeds, it is common to adopt multi-support configuration, which indicates that the optimization is a multi-objective, multi-variable and non-deterministic problem, taking into account parameter uncertainties. An equa...

Aimed at the conflict problem of military aircraft flow passing through civil aviation routes, the aircraft flow centering scenario is modeled and analyzed. A centering flight conflict detection method based on sliding windows and a multiple aircraft conflict resolution method based on cooperative g...

In order to improve the segmentation effect of oil wear debris image and optimize the main content of automatic recognition of wear debris, an adaptive segmentation method of oil wear debris image which combines watershed algorithm and regional similarity has been proposed. First, the gradient image...

According to the eigenvalue condition of cantilever beam with tip mass and spring, this paper proposes a characteristic transformation method, and obtains the analytical solutions of generalized mass and vibration response of cantilever beam with constraints. By analyzing the variational regularitie...

As one of the core components of spaceflight optical remote sensor, the temperature of the charge-coupled device (CCD) will affect the working performance. Therefore, traditional thermal control products have gradually been difficult to meet the needs of high-power CCD precise temperature control. I...

A solution to the stage of state-keeping after tether deployment or stage of tether in-plane motion stabilization after payload capture with space tether system (STS) in the case of incomplete state feedback is proposed, which is based on matrix decomposition. Feedbacks of in-plane angle and its ang...

Initial alignment is a key technology of rotary strapdown inertial navigation system (SINS). The existing 10D model of traditional rotary SINS is mostly used for the fine alignment, which cannot meet the requirements of navigation accuracy. To solve this problem, a fine alignment method for rotary S...

Extended finite state machine (EFSM), a more accurate test model than finite state machine (FSM), has been widely used to describe dynamic behavior of system, and thus has been taken as the test model of various control flow and data flow systems. For EFSM model test, using search method to obtain t...

For optimization of the modular reconfigurable airfoil structures, three wing modules that distributed along the span direction are taken as research object, and the correlations of load among airfoils with different wingspan are investigated. The complex coupling effects between variables and const...

In order to enhance the flight performance and load capacity of high-altitude solar-powered UAV, a three-dimensional optimal path planning model that examines the interaction between flight status, energy acquisition, storage, and consumption was established. The Gauss pseudo-spectral method was emp...

Aimed at the problem that the existing algorithms are not ideal to enhance foggy images with non-uniform fog distribution, this paper proposes a foggy image enhancement algorithm based on multi-block coordinated single-scale Retinex. Different from traditional Retinex algorithms that use the global ...

A equivalent fault injection method based on failure mode-function-state (FFS) failure behavior model is proposed to deal with the incapability of fault injection and permanent damage caused by fault injection in the fault injection based testability verification test. Firstly, the general FFS model...

In solving the identification problem of linear parametric variation (LPV) model, the least squares algorithm is widely used due to the advantages of simple structure and low computational complexity. However, the results of least squares algorithm are subject to computational accuracy and model app...

The phase change material based passive heat sink is widely applied in the fields of aerospace and military equipment. To address the thermal management of electronic chip with high heat flux, the single temperature energy equation and the two temperature energy equation were applied to simulate the...

To solve the problem of high-order derivation and reliability evaluation of optimization results in the multi-coil system magnetic field uniformity optimization design, an optimization design method based on intelligent optimization algorithm and finite element method is proposed. First, the paramet...

In order to study the effect of air-inlet structures on combustion and ablation combustion chamber of solid ramjet, the flow field characteristics in the secondary in the secondary combustion chamber of solid rocket ramjet with bilateral 180° air-inlet structure and bilateral 90° air-inlet structure...

The modeling of satellite micro-vibration isolators is the basis for further simulation, optimization and control of system vibration. Because the model of five-parameter fractional derivative cannot describe amplitude variable performance of the damping satellite vibration isolator, according to th...

The stratospheric wind environment has an important influence on the aerostat design and trajectory control. Taking the wind field data from 2005 to 2010 in Changsha as an example, this paper firstly uses the proper orthogonal decomposition (POD) method to reduce order of the wind field data, and th...

Liquid fuel volatile compositions play an important role for ignition at low temperatures. The composition distribution of aviation kerosene RP-3 and coal-based Fischev-Tropsch F-T fuel in the vapor phase under low temperatures were analyzed in this research. The volatile components and content dist...

The periodic self-oscillation of the shock wave of the transonic airfoil will bring additional oscillating loads to the wing structure, thereby aggravating the fatigue damage of the aircraft structure. The dynamic mode decomposition (DMD) method is used to study the pressure fluctuation field of a s...

The numerical simulation prediction of aero-icing ice shape is usually complicated and time-consuming. In order to predict ice shape more quickly and accurately and to reduce computational resource consumption, a quick ice shape prediction method based on proper orthogonal decomposition and Kriging ...

Model-based systems engineering (MBSE) theory has been widely used in the civil aircraft design and functional requirement analysis. Firstly, the research starts from the top-down use case of civil aircraft system product based on user requirements to identify the relevant key sub-use cases. Secondl...

In cloud computing, access control and security are two major problems, and there are some differences from traditional identity authentication. Inspired by the semi-group and chaotic properties of Chebyshev polynomials, a scheme of password-authenticated key agreement using Chebyshev chaotic mappin...