Abstract:The sustained and rapid growth of global air transport demand has caused many hub airports to face a series of challenging problems, such as high-frequency flight conflicts, large-scale airspace congestions, and wide flight delays.. This work focuses on the research hotspots and challenges of airfield resource scheduling problem, which is part III of the whole research. The classification of airfield resource scheduling is undertaken from multiple perspectives, and some research hotspots in recent years are reviewed, including capacity forecast, mode configuration, situation awareness, airborne ground scheduling and performance analysis. Then, a comprehensive analysis of major challenges facing the research field is conducted. This paper is aimed to provide scientific guidances and references for the sustainable development of theory and practice in airport operation management.

Abstract:There have been a considerable number of accuracy indexes for surrogate models in references. However, most of these indexes are not capable of comparing surrogate models of different data types. In this paper, the drawbacks of the existing indexes were firstly discussed. Then a new index named "Mean Normalized Absolute Error (MNEA)" was introduced. Kriging models of 11 different types of aerodynamic parameters from a tactical missile model were built, with the adding-points design of experiment method and cross-validation verification methods. The effectiveness of MNEA was verified by comparing the MNEA value and the correlation plots of the example, which had proved that MNEA can be used to compare the accuracy of surrogate models of different data types.

Abstract:A concurrent subspace optimization method is developed for the layout design of wings. In terms of the type of variables, the design problem of structures is decomposed into three concurrent subspaces with spar location, stringer and thickness optimization. The optimization in each subspace is carried out separately to avoid the coupling of design variables. By remaining the design variables in the lightest subspace unchanged and altering two other types of variables with approximate one-dimensional search algorithm, the coordination is achieved in system level to ensure the convergence of the analysis problem. Then next iteration is executed until termination. An UAV example is solved successfully to demonstrate that the proposed method is feasible and has practical engineering value.

Abstract:Accurate track prediction is basis for improving the early warning capability for air threat situation of anti-collision, for this reason, an improved sliding window polynomial fitting track prediction method is proposed to intrusion aircraft. It mainly made two improvements: the first is to construct a suitable polynomial fitting equation for each predicted value in the sliding window for the prediction of several future values after the current values; the second is to adaptively adjust and fit the polynomial order and sliding window length according to the current track value and the target motion mode information reflected by previous finite continuous track value. Simulation result shows that, compared with traditional sliding window polynomial fitting method, the proposed method has better track prediction accuracy. It can improve the track prediction accuracy of non-cooperative aircraft to some extent, which validates its feasibility and effectiveness in track prediction.

Abstract:Traditional critical links identification standards are incomplete and simple in aviation networ. To solve these problems, a comprehensive evaluation index of the links’ comprehensive importance is proposed based on the three network importance evaluation indicators. A double evaluation standard for the increase and decrease of link capacity is established. The effectiveness of the identification method is verified by constructing a network model of air traffic flow distribution model based on UE model. The test results show that the dual capacity identification standard based on the comprehensive importance evaluation index of the flight link can comprehensively and effectively identify the potential key links in the aviation network.

Abstract:Air space is an important national resource. Its use and deployment affect the security and development of the country. In wartime, more air resources will be allocated to military flights, which will help guarantee military operations. Therefore, a wartime aviation network planning method based on binary particle swarm optimization algorithm is proposed. First, model the aviation network and collect flight data. Secondly, an evaluation system of aviation network performance is established. Then, BPSO algorithm is used to solve the problem. The goal of the solution is to maintain the expected network performance with as few civil airports as possible. The constraint conditions for the solution are operational intent and battlefield environment. Finally, the simulation analysis is carried out. The results show that the method can combine the combat intention, reflect the battlefield environment and reasonably allocate the aviation resources, and provide decision-making basis for the wartime aviation control work.

Abstract:The vertical take-off and landing fixed-wing UAV has the advantages of convenient use and superior performance, and is the key direction for the development of UAVs in the future.The vertical take-off and landing fixed-wing UAV is designed with the drooping tail of the wing tip to be used as a vertical tail with both wingtips and landing gear.In order to understand the aerodynamic influence of the wing tip vertical tail on the whole of the UAV, the paper compares the four wingtip designs of the drooping tail, upper vertical tail, wing tip end plate and conventional layout.The aerodynamic characteristics of the four designs are simulated and analyzed by using LBM-LES algorithm and the wall self-adaptive local vortex viscous large eddy simulation turbulence model.The analysis results show that the drooping tail of the wing tip is more efficient than the other three designs in the leveling state; the stability against the crosswind is better in the vertical takeoff or landing state.

Abstract:Abstract: Aiming at the research blank of the reliability evaluation of high failure rate Line Replaceable Unit (LRU) and the location of LRU fault component in the aviation maintenance, a reliability evaluation simulation model applicable for LRU "replacement maintenance" strategy is designed, the design principle and the actual methods as well as steps of each function module in the model are introduced in detail. Finally, the model is applied and analyzed to a common high failure rate LRU in a certain type of aircraft hydraulic system as an example, the conclusion shows that the simulation model is practical and universally applicable to the reliability evaluation of LRU.

Abstract:The M2 light sport aircraft structure is constructed of composite materials and designed in accordance with ASTM 2245-16 airworthiness specifications. The composite material is an anisotropic material, and environmental factors such as temperature and humidity will reduce the material properties. The environmental impact factor must be established, and the structural load after considering the environmental impact factor will increase. The wing loads need to consider bending, torsion and shear loads. The load conditions include maneuvering loads, gust loads, and inertial loads. The wing load distribution needs to consider the distribution of lift and gravity. The composite wing load was calculated by studying the M2 aircraft load envelope, environmental impact coefficient, limit load and ultimate load. The static test of the wing of the M2 aircraft is based on the symmetrical structure of the wing bearing force, and the sandbag loading on the wing is adopted; The wing root is fixedly supported, and the left and right wings are symmetrically loaded. The wing-limited load static test, the wing ultimate load static test and the wing damage load static test were carried out; The results of the wing static test show that the ultimate load of the M2 aircraft meets the test requirements, and the deviation of the composite wing test failure load relative to the design limit load is 2%. M2 aircraft composite wing structure design meets static strength design requirements. This paper has engineering guiding significance for the structural design of lightweight sports aircraft composites.

Abstract:The emergency evacuation demonstration test of transport aircraft is an important testing link through the type certification. The test involves a large number of personnel, and the items and types of airworthiness certification check are complicated. In order to formulate a more reasonable test plan, it is necessary to carry out a systematic analysis of documents related to airworthiness requirements for emergency evacuation of transport aircraft and their advisory notices. For the whole process of the aircraft emergency evacuation demonstration test, research is carried out from four aspects: pre-preparation, on-board inspection, test and post-test., test and post-test. Defining the basic process of airworthiness certification, summarizing the airworthiness certification elements and specific verification methods.

Abstract:Intelligent allocation and scheduling of airport security-check service resources is one of the effective ways to improve passenger service level and operational efficiency within the airport, while the accurately prediction about the security passenger traffic is the prerequisite for dynamic allocation and scheduling. This paper takes the historical passenger data at Tianjin airport security inspection as the research object, and puts forward a prediction method based on BP neural network so as to establish a prediction model of security-check passenger flow. Besides the proposed model by this paper is verified by the actual passenger flow of Tianjin airport, as we can know from the comparison results, the accuracy of the proposed algorithm can reach to above ninety percent, So the BP neural network prediction model behaves with higher forecasting accuracy, can be well applied to the security-check flow prediction in the airport terminal, which can support a high efficiency solution for the airport operators to dynamically allocate security-check services resources.

Abstract:This paper explores the multiple local characteristics of the RAE2822 in the process of minimising drag optimization. AIAA Aerodynamic Design Optimization Discussion Group(ADODG) case 2 is used. The airfoil is parameterized by using the FFD (free-form deform) parameterization technique, and the initial perturbation is added to the airfoil by using the uniform latin hypercube method. Then the gradient-based optimization algorithm is used to optimize the airfoil after different disturbances, and the optimization results are compared with the optimization results of the global optimization algorithm. The results show that ADODG case2 is a convex peak design problem. The gradient-based algorithm can obtain a relatively satisfactory optimal solution and has a higher optimization efficiency. The conclusion can be inferred from this study that airfoil transonic minimising drag optimization subject to area constraint is possible a convex peak design problem. Gradient optimization algorithms can be used directly.

Abstract:This paper proposes a new design method of osculating-cone waverider. Based on the conical flow field, with Flow Capture Curve (FCC) and Inlet Capture Curve (ICC) unchanged, a new curve is introduced to broaden the design space of conventional osculating-cone waverider. By adjusting the radius of curvature of the exit shock to achieve the purpose of changing the volume and volume efficiency of the waverider, in this study, four kinds of waveriders are designed, including the traditional osculating-cone waverider, the shock radius-reduced waverider, the shock radius-lengthened waverider, the waverider with straight line ICC. The CFD numerical simulation method was used to compare and analyze these waveriders designed in this paper. The results show that under the inviscid condition, the waverider with low volume efficiency has a larger lift-to-drag ratio; under viscous conditions, these four waveriders behave close lift-to-drag ratio property, but the waverider newly designed in this paper has a larger volumetric efficiency and better engineering application value.

Abstract:Based on the cell-centered finite volume methods (FVM), an improved unstructured overset grids interpolation method is proposed. The main improvement is to control the condition number of interpolation matrix by adjusting the radius of Wendland’s C2 radial basis function. Furthermore, the numerical singularity in the overset boundary region of radial basis function interpolation is eliminated. Using known analytic functions as interpolation samples, the accuracy of four interpolation methods, namely linear interpolation(LINE), weighted interpolation by reciprocal distance (WA), inverse quadratic radial basis function interpolation(IQ), Wendland’s C2 radial basis function interpolation(C2) were investigated. The inverse quadratic radial basis function IQ and C2 radial basis function with high accuracy were selected for further study. Then the transonic flow field of RAE2822 supercritical airfoil was simulated by using the above two radial basis functions. It is found that the flow field in the overset region of C2 radial basis function interpolation is smoother, the convergence rate is faster and the interpolation accuracy is higher. Through the numerical simulation of MD30P/30N multi-segment airfoil flow field, the effectiveness of conditional number control interpolation method in eliminating interpolation oddness is verified. Finally, the equations of six degrees of freedom rigid body are coupled, and the typical model of AEDC plug-in separation model is calculated and analyzed under the condition of transonic velocity. The accuracy and robustness of the developed conditional number control radial basis function interpolation method are further verified.

Abstract:The open cavity flow contains various physical phenomena relating to vortex structures. The study on the vortex dynamics in the open cavity can provide theoretical insights into flow control and noise reduction. Direct numerical simulation is performed to obtain high order accuracy flow field of the open cavity. The vortex structures are identified using the Lagrangian coherent structures. Together with the Q-criterion and vorticity flux analysis, the formation, convection, impingement and split of the vortex in the cavity is studied and the dynamical characteristics are revealed. It’s found that the rolling up and shedding of Lagrangian coherent structures at the leading edge corresponds to the formation and shedding of the vortex. The split of Lagrangian coherent structures corresponds to the split of Q and Vortex. The main vortex in the cavity remains stable during the whole period of the flow.

Abstract:In order to assess the influence of turbulence-combustion interaction on the supersonic combustion.Investigate different distributing based on assumed probability density function models.consider temperature and component fluctuations,usingβ-PDF and δ-PDF to simulate the Hypersonic International Flight Research Experimentation(HIFiRE2) direct-connect engine,and compared with the actual wind tunnal experimental results.The research result showed:(1) Compared with RANS result, the PDF model can be more accurate to describe the flow field of HIFiRE2,and in agreement with experimental results closely,this found that turbulence-combustion interaction can’t be ignored.(2) β-PDF model is better while predicting the wall pressure distribution,and get higher combustion efficiency,could be more accurately while predicting the turbulence-combustion interaction.

Abstract:The aerodynamic heating effect of the aircraft during supersonic flight has a great impact on the structural strength and thermal protection design. The aerodynamic thermal environment in the real state needs to consider the coupling of the external flow field and the structure and the influence of the boundary conditions of the inner wall surface. The S-A turbulence model is used to solve the Navier-Stokes equation. The coupling of the flow field and the solid wall is used to realize the coupled numerical analysis of the external flow field and the structural field. The coupling numerical study of the supersonic flow aerodynamic heating of three different airfoils is carried out, and the aerodynamic thermal effects of the inner wall surface of the airfoil under different thermal boundary conditions are compared. The results show that different airfoils have aerodynamic thermal effects similar to aerodynamic forces. The boundary condition of the inner wall considering convective heat transfer is the closest to reality; considering the fuel tank of the wing is full, the heat flux at the leading edge of the 3D wing can be up to 4200w/m2.

Abstract:Maxwell equations of electromagnetism are hyperbolic partial differential equations with real characteristic values as the non-viscous Euler equations of hydrodynamics, so the same mathematical characteristic makes it possible to apply computational fluid dynamics (CFD) techniques into computational electromagnetism (CEM) to get high precision electromagnetic fields. The finite volume time domain method (FVTD) is used in this paper, where flux vector computed by MUCSL scheme and Steger-Warming splitting method, unsteady time marching computed by 4 steps Runge-Kutta method, and the treatment of electromagnetic boundary conditions using the same techniques as in CFD. In the end, through the numerical simulation of electromagnetic scattering of wideband pulse wave, perfect conductor, media coated conductor and complex shape objects, it demonstrated that FVTD method based on CFD can calculate objects electromagnetic characteristic with a better precision.

Abstract:Due to the existence of solar panels, the installation height and wheelbase of the rotor have an impact on the aerodynamic performance of the whole machine. The non-constant constant value simulation of the flow field of the whole machine is carried out by XFlow software based on the particle method lattice Boltzmann technique. The simulation results show that the height of the rotor has little effect on the lift of the whole machine. The larger the installation wheelbase of the rotor is, the larger the lift of the whole machine is. The main reason is that when the wheelbase is small, the lower wash flow generated by the rotor impacts on the board. The whole machine produces pneumatic interference. According to the simulation results and the whole machine, the analysis shows that the best installation method of the rotor is half-wheelbase R=859mm and height H=55mm, and provides some reference for the design of similar aircraft in the future.