Abstract:The emergency evacuation of passengers and crew on a civil aircraft is a man-machine-environment multi-system coupling process, which involves complex factors such as human behavior, cabin environment, disaster situation, etc. Cabin layout, personnel attributes, emergency measures all have a significant influence on the process and results of emergency evacuation. As emergency evacuation is directly related to the safety of civil aircraft, the airworthiness standard of transport aircraft requires that civil aircraft with more than 44 seats must perform a full-scale emergency evacuation test for airworthiness demonstration, demanding the evacuation process to be completed within 90 seconds under specified environmental conditions. This paper outlines the airworthiness requirements of civil aircraft for emergency evacuation, summarizes the experimental research methods and numerical simulation methods of emergency evacuation, and prospects the research trend about emergency evacuation combined with the future requirements of civil aircraft safety design and the development of related technologies.

Abstract:Paired approach(PA) mode is an efficient approach mode that operates on Closely Spaced Parallel Runways(CSPRs) and aims to improve the approach efficiency under Instrument Meteorological Conditions(IMC). The complete process of this mode is rarely elaborated in China. This paper mainly analyzes the opreational process and definite running requirements of the Paired Approach procedure on CSPRs; Combined with the present domestic CSPRs operation of the airport and PA model research and application status of the urgency of the proposed PA model introduced into China, and the research direction in the future.

Abstract:Cloud operation is a new operational mode brought by cloud computing technology in the military field. In the future aviation and space information confrontation, cloud operation will have the invisible power application and the combination of virtual and real combat operations. This paper analyzes the construction requirements of aviation and space information equipment system. Based on the concept of cloud computing and cloud operation, aviation and space information equipment system is constructed. The paper discusses the enlightenment of the cloud operation concept to the construction of aviation and space information equipment system. The revelations are emphasizing the research on the winning mechanism of cloud operation, enhancing equipment integration capability, focusing on reliability and safety, adhering to overall coordination, etc.

Abstract:In the simulation of emergency evacuation of aircraft, the cellular automaton model is mostly used to simulate evacuated people. This model is faster in calculation but regards the evacuees as the same particles, ignoring individual differences, so there is a difference from the actual evacuation situation . In this paper, the agent model is used to establish personal behavior rules, combined with the A* pathfinding algorithm, a valuation function in the A* algorithm suitable for aircraft emergency evacuation is proposed, and a character model is established. Finally, the simulation of the emergency evacuation process of the cabin of a certain type of Boeing 737-700 aircraft was carried out, and compared with the previous experimental results and the authoritative simulation software airEXODUS. The simulation results were close to the real experimental results. Therefore, an agent-based algorithm suitable for passenger cabin emergency escape simulation is proposed. Compared with the cellular automaton model used by traditional algorithms, this algorithm is closer to the real evacuation situation.

Abstract:The purpose of the dummy high speed airdrop test is to evaluate the maximum overload on the human body during the process of opening the parachute. Due to the poor repeatability and high cost of the test, it is necessary to establish a calculation model to provide theoretical basis for the system design. Based on impulse theorem, the maximum dummy overload calculation model is established to calculate the maximum dummy overlord quickly under a certain airdrop condition. The typical high speed airdrop system is selected as the instance to conduct the system simulation based on multi-body dynamics. The key parameters of the calculation model are determined by simulation results, and the mathematical expressions of the maximum dummy overlord calculation model are given. The results show that the calculation model can quickly and effectively determine the maximum dummy overlord, evaluate the safety of the life-saving parachute system, and has high engineering application value.

Abstract:With the rapid development of hypersonic vehicle technology, the research of the defense approach of the hypersonic weapons is becoming more and more important. A lot of guidance law researchers made their efforts to tackle with the problem of high speed, active large scale maneuverability of the hypersonic targets. In this paper, we defined this interception problem as a typical differential game, and we used the adaptive dynamic programming method to learn the Nash Equilibrium solution of the nonlinear continuous time system. At last, the numerical simulation is provided, the result shows that the proposed method is more robust than the baseline method.

Abstract:Considering the safety when aircrafts is taxing in the taxiway, one of the most important is to predict the conflict among aircrafts to avoid the conflict between two aircrafts. This paper presents a time bucket-based method taking the distance between aircrafts as standard. When considering the probability of conflict as standard, we assume that the position of aircraft follows two-dimension normal distribution first. Next step is to calculate the probability of conflict at any given time based on last algorithm. Through calculation shows that longitudinal and latitudinal variance accumulation effect should be considered when some uncertain factors exist in aircrafts’ taxing. Therefore, both the probability of conflict and the distance between aircrafts should be taken as standards in practice to assure the safety of the aircrafts.

Abstract:As a highly complex project, the complex aviation product research and development project requires many participants. In order to ensure the effectively process of complex aviation product research and development project, it is necessary to evaluate the effectiveness of the project’s organizational structure. Five first-level key indicators of goal accomplishment, internal processes fluency, resources management ability, stakeholders’ support and environmental adaptation are set. Five first-level key indicators are further broken down to establish the effectiveness evaluation indicator system of complex aviation product research and development project. The analytic hierarchy process method and grey clustering evaluation model based on mixed probability function of central point are used to perform the effectiveness evaluation of organizational structure for complex aviation product research and development project. The evaluation model is applied to a certain instance to verify the effectiveness of the evaluation model. The results show that the model can evaluate the organizational structure effectiveness of complex aviation product research and development project.

Abstract:Airborne laser weapon system can increase the survivability of the aircraft by active defense. In order to obtain longer fire range, a large diameter of the airborne laser weapon turret is required, which may cause negative influence to the aircraft. In this paper, the influence of turret diameter on aerodynamic and stealth performance of the aircraft is analyzed by means of computational fluid dynamics method and physical optics method. And the influence of turret diameter on combat effectiveness is analyzed with agent-based combat simulation. The results show that the increase of turret diameter will lead to a slight decrease of aircraft speed, while the influence quantity of laser turret to aircraft speed is within 2%. In the meantime, the increase of turret diameter increases the front RCS of the aircraft, an diameter of 30cm, 50cm and 70cm of laser turret could lead to an increase of 64%、173% and 282% of the aircraft RCS. The 50cm diameter design could increase the most mission effectiveness, which is 77.2%.

Abstract:The nonlinear flutter problem of aeroelastic system with freeplay nonlinearity has become one of the hottest and most challenging topics in the engineering field of aircraft aeroelasticity. The nonlinear aeroelastic behaviors of the control fin with freeplay nonlinearity are analyzed in the study. The reduced-order aerodynamic model in time-domain is obtained by using the minimum state approximation method, and then the nonlinear aeroelastic equations of the control fin can be obtained based on the Lagrange equation. Using the numerical method, the aeroelastic system behaviors with freeplay nonlinearity in either pitch or plunge, or both of them are studied, including limit cycle oscillations (LCOs) and nonlinear dynamic responses. The numerical results are compared with those of the equivalent linearization method. The results show that the stiffnesses of pitch and plunge springs have significant influence on the flutter boundary of the system. And when the free-plays are both in pitch and plunge, there exists complex dynamic phenomena including the multi-periodic LCOs and chaotic motions.

Abstract:It is found that the rolling characteristic after airplane stall is rapidly changed, when the wind tunnel test prediction is conducted for the small commuter category airplanes. On the basis of analyzing the wind tunnel test results of the airplane, the stalling characteristic method that the stall strips is added on the wing is adopted, and the flight verification is performed by using free-flight test of scaled-model. After adding stall strips on the wing and the original wing, the flight results are analyzed under the states of cruising structure and landing structure. Results show that the scaled-model free-flight test can verify the prediction results of the wind tunnel test, and the stalling characteristic improved method by adding stall strips can improve the stall characteristic of airplane.

Abstract:The design ability of composite structures brings large-scale design variables, which makes it difficult to optimize structures by traditional methods, the optimization design of composite laminates is also one of the key problems. From the perspective of engineering design, multiple models are arranged for laying optimization, based on the design of composite super-ply variable definition, considering the overall engineering design constraints to sizing optimization, automatic strength checking process with the laying sequence library to optimize the laying sequence, forming a set of optimization design method of composite structure with three levels of laying optimization, initial size optimization and detailed laying optimization. Taking the structural design of composite vertical tail box of an aircraft as an example, this method is used to optimize the design of composite vertical tai lbox. The results show that: the three-level optimization design method proposed in this paper is a general method applicable to the optimization design of aeronautical composite structures. It reduces the weight of the structure and shortens the development cycle.

Abstract:Abstract: the main failure mode of composite stiffened panel is buckling. In order to ensure the safety of the structure and effectively reduce the weight of the structure, it is necessary to systematically study the boundary conditions and the width of the load-bearing edge of the skin when checking the buckling. Through the study of two kinds of boundary conditions and three kinds of skin load edge width selection, a method of skin load edge width selection considering the influence of stringer is put forward to calculate the buckling of stiffened panel and verify with the test results. The research results show that the engineering buckling calculation method with the boundary conditions of four sides simply supported and the width of the loading edge of the skin considering the influence of the stringer has the highest accuracy, the minimum deviation between the calculation results and the test results is 0.29%, the maximum deviation is 7.16%, and all of them are lower than the test values. It is safe and reliable to use this method to check the strength and stability of structures. Key words:composite;stiffened panel;buckling;engineering calculation method.

Abstract:In order to solve the problem about quickly construct, rapidly adjust and effective testing of airborne equipment sensitivity in reverberation chamber high-intensity radiation field environment. In the frequency band of 400 MHz to 2 GHz, a helicopter airborne radio station was used as a test subject in the reverberation chamber high-intensity radiation field radiation sensitivity test system, the typical fault type and sensitivity threshold of the test equipment were respectively determined in different working modes of the reverberation chamber by changing the electric field strength. The results show that the sensitivity threshold of the airborne radio station can be measured more easily in agitator continuous mode than step-by-step operation mode under the same conditions as the test environment field. In continuous working mode, the sensitivity threshold of the airborne radio station was tested decreases with the faster stirring speed and the tested results of sensitivity threshold decreased with the increase of pulse width. The results of study are helpful to perfect the test methods and standard specifications about the electromagnetic radiation protection performance of airborne equipment.

Abstract:Colleges and universities carry the mission of servicing the national policy needs and the development of the national economy, training and projecting high-level talents in various fields. The training of talents in colleges and universities is very important, and the quality of the enrollment source has an important influence on the training of talents, and it is related to the goal and quality of talent training. In recent years, with the reform of the new college entrance examination, colleges and universities have faced great challenges and opportunities for undergraduate enrollment. This article takes the aerospace undergraduate source of Northwestern Polytechnical University as the research object, combines the school's admission policy and admission data in recent years, analyzes the factors influencing the quality of the school's aerospace student source from the three aspects of school propaganda, social practice, and local policy. According to data analysis, it is found that vigorously carrying out high-quality enrollment publicity is its principal influence factor, and applicable countermeasures are put forward around the enrollment publicity work.

Abstract:Flight load design is an important part of aircraft design. It is a bridge connecting the General&Aerodynamic and Structure&Stress. In this paper, the development of flight load design is reviewed in terms of the specifications to be followed, the design methods, and the verification of flight load, especially focuses on the design methods, the selection of severe case and the verification method, and summarizes the advantages and disadvantages of existing design verification methods, and The development direction in the future are carried on.

Abstract:The flight load testing technology has important implications for load designing, strength flight test and life monitoring of the aircraft. In order to obtain the real-time distributed load on the complex wing surface, the data-driven load estimation method is proposed. The artificial neural network is established by deep-learning method. The data set of the structural response for the agent model training is generated by the high-precision finite element method. The deep learning results are verified by comparing with the FEM calculation results, the average error of the total load is about 0.2% and the position error of the pressure center is about 1%. The results show that the whole wing structural load can be estimated using the deep learning model with data from several strain test points in real time.

Abstract:Prediction and limitation of inlet pressure are important for supersonic vehicles. In this paper, numerical simulation on high speed inlet flow is conducted, and pressure characteristics with different Mach numbers, attack angles, yaw angles and excess air coefficients is analyzed. Based on dimensionless and decoupled method, empirical formula for high speed inlet pressure is fitted and verified by flight results. The results show that, with the Mach number increasing and excess air coefficient decreasing, the pressure in inlet increases. Attack angle and yaw angle have little influence on inlet pressure in normal work envelope. The inlet pressure estimated by empirical formula is in good agreement with measured data in flight tests, which means that the formula established in this paper has a high precision.

Abstract:Based on yaw maneuver situation stipulated in article 25.351 of CCAR-25 and rudder control reversal situation stipulated in article 25.353 of CS-25, this paper firstly makes an understanding of article CCAR25.331 and CS25.353, then carries out maneuver simulation calculation for two yaw maneuver situations with/without the consideration of control law respectively, and finally makes a comparative analysis of the aircraft response and the vertical-tail load. The results of calculation and analysis show that: 1) for the yaw maneuver situation, the response attitude of the aircraft is reduced after considering the control law, and the vertical-tail load is reduced; 2) after considering the rudder control reversal, the response attitude of the aircraft and beta are increased, and the vertical-tail load is finally increased;3) the vertical-tail load caused by the rudder control reversal can effectively be reduced after considering the P-Beta control law.

Abstract:In order to make the design of landing gear to fulfill the requirements of the airship criterion FAA-P-8110-2, a methodology of load calculation for landing gear was presented in this paper, which was based on the double-springs' vibration model. In term of the typical theories of dynamics, the differential equations of the system were derived herein. A simulation tool for this model was developed based on Python scientific modules, which was built in visualization and friendly operation. Based on a manned airship, the main factors affecting the load of the landing gear are analyzed, and the reasonable values of the load are obtained by simulation. The results of this paper can be used as the inputs for structural design and strength analysis of airship landing gear.