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Performance Analysis on Retractable Landing Gear and Design of Ground Test System

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第6期33卷 -页

作者： Wang hongxian nie hong Key Laboratory of Unmanned Aerial Vehicle Technology of Ministry of Industry and Information Technology Nanjing University of Aeronautics and Astronautics State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics

Landing gears are one of the key components for large or middle unmanned aerial vehicles,and their working performances directly affect flying security and aircraft taking-off and landing ***,it is meaningful to study the retraction *** on CATIA and ADAMS software platforms,a virtual model of landing gear retraction system is built for performance test,and then dynamic simulation is carried ***,a test system for landing gear retraction is established,and the test data are compared with the results acquired from dynamics *** main factors which affect the dynamic performance of retractable landing gear are analyzed *** simulation results show that aerodynamic load has an impact on retraction time,the mass force affects extension process,and the oil hole size of hydraulic actuator has an effect on both retraction time and extension time.

关键词： landing gear retraction system dynamic simulation experiment system

Design and Dynamics Analysis of Anti-skid Braking System for Aircraft with Four-wheel Bogie Landing Gears

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Chinese Journal of Mechanical Engineering 2011年第2期24卷 277-284页

作者： ZHANG Ming nie hong ZHU Rupeng Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics andAstronautics Nanjing 210016 China

In asymmetric conditions,the movement and loads of left/right wheels or front/back wheels of the aircraft with multi-wheel or four-wheel bogie landing gears are *** are few open literatures related to anti-skid braking system for multi-wheels due to technology *** China,the research on multi-channel control and non-equilibrium regulation has just started,and the design of multi-channel control system for anti-skid braking,the simulation of asymmetry taxiing under braking are not *** this paper,a dynamics model of ground movement for aircraft with four-wheel bogie landing gears is established for braking simulation, considering the six-degree-of-freedom aircraft body and the movement of bogies and wheels.A multi-channel anti-skid braking system is designed for the wheels of the main landing gears with four-wheel *** eight wheels on left and right landing gears are divided into four groups,and each group is controlled via one *** cross protection and self-locked protection modules are added between different channels.A multi-channel anti-skid braking system with slip-ratio control or with slip-velocity control is established *** on the aircraft dynamics model,aircraft braking to stop with anti-skid control on dry runway and on wet runway are *** simulation results demonstrate that in asymmetric conditions,added with cross protection and self-locked protection modules,the slip-ratio-controlled braking system can automatically regulate brake torque to avoid deep slipping and correct aircraft *** proposed research has reference value for improving brake control effect on wet runway.

关键词： anti-skid braking system four-wheel bogie landing gear multi-channel control dynamics model

Study on modal characteristics and vibration reduction of an aircraft rotor–stator brake-induced squeal system

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Acta Mechanica Sinica 2020年第6期36卷 1350-1359,I0004页

作者： Qiaozhi Yin Xiaohui Wei hong nie Jian Deng State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and AstronauticsNanjing210016China Nanjing Center for Multifunctional Lightweight Materials and Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

Based on the modal coupling theory,the rotor and stator contact stiffness and axial relative velocity are considered to build an electric aircraft brake dynamic system model in this *** the complex modal analysis and transient dynamic analysis methods are used to study the aircraft brake squeal performance and vibratory *** unstable vibration modes indicate that the out-of-plane vibration plays an important role and the feed-in energy is larger than the output energy in the brake rotor–stator module so that brake squeal takes *** the influences of the contact stiffness,friction damping and frictional coefficient on the brake squeal system are carried out,laying the foundation for the three proposed vibration suppression *** show that the coefficient negative-slope condition will intensify the ***,a linear relationship between the squeal factor and the frictional coefficient is obtained to provide a guidance to predict squeal stability under more *** reduction design shows that adding a damping layer to the brake mechanism and chamfering the edge of braking stators both can reduce brake squeal effectively,while slotting braking stators is invalid in aircraft braking system.

关键词： Aircraft rotor-stator bake-induced vibration Brake squeal-Vibration stability Modal coupling Vibration suppression

Optimization design containing dimension and buffer parameters of landing legs for reusable landing vehicle

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Chinese Journal of Aeronautics 2022年第3期35卷 234-249页

作者： Bo LEI Ming ZHANG Hanyu LIN hong nie Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory of Mechanics and Control of Mechanical Structure Nanjing University of Aeronautics and AstronauticsNanjing 210016China

For the landing legs with single air chamber in the buffer structure of the reusable landing vehicle,the geometric topological models and the dynamic model associated with the hard points of the landing legs are *** geometric constraint relationship in the design of the landing legs is also *** whole vehicle dropping test is conducted,and the test results agree well with that of the simulation model,which validates the dynamic *** on the verified model,the effect of hard point positions on the performance of the landing system is *** multidisciplinary collaborative optimization algorithm and archive-based micro genetic algorithm(CO-AMGA)are used to optimize the design parameters that contain the hard points and the *** with artificial iteration,the maximum landing impact acceleration response of the vehicle and the buffer struct maximum force are reduced by 30.70%and 14.51%respectively,and the maximum length of retractable pillar decreases by 8.54%while the design margin increases by 69.11%.The proposed optimization method is efficient and can greatly facilitate the design of landing legs.

关键词： Dynamics Impact test Landing system Optimization design Reusable landing vehicle

Parameter effects on high-speed UAV ground directional stability using bifurcation analysis

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Chinese Journal of Aeronautics 2021年第11期34卷 1-14页

作者： Qiaozhi YIN Xiaohui WEI hong nie Jian DENG State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and AstronauticsNanjing 210016China MIIT Key Laboratory of Multifunctional Lightweight Materials and Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

A loss of ground directional stability can trigger a high-speed Unmanned Aerial Vehicle(UAV)to veer off the *** order to investigate the combined effects of the key structural and operational parameters on the UAV ground directional stability from a global perspective,a fully parameterized mathematical high-speed UAV ground nonlinear dynamic model is developed considering several nonlinear *** bifurcation analysis procedure of a UAV ground steering system is introduced,following which the simulation efficiency is greatly improved comparing with the time-domain simulation *** the numerical continuation method is employed to investigate the influence of the nose wheel steering angle and the global stability region is *** bifurcation parameter plane is divided into several parts with different stability properties by the saddle nodes and the Hopf bifurcation *** find that the UAV motion states will never cross the bifurcation curve in the nonlinear ***,the dual-parameter bifurcation analyses are presented to give a complete description of the possible steering *** is also found that BT bifurcation appears when the UAV initial rectilinear velocity and the tire frictional coefficient *** addition,results indicate that the influence of tire frictional coefficient has an opposite trend to the influence of initial rectilinear ***,using bifurcation analysis method to identify the parameter regions of a UAV nonlinear ground dynamic system helps to improve the development efficiency and quality during UAV designing phase.

关键词： Bifurcation analysis Ground directional stability High-speed UAV Nonlinear system Numerical continuation

Parameter Optimization of Nose Landing Gear Considering Both Take-off and Landing Performance of Catapult Take-off Carrier-Based Aircraft

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第2期33卷 187-198页

作者： Zhang Ming nie hong He Zhihang Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and Astronautics State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics

Optimization of the parameters of landing gear systems with double-stage air springs of catapult take-off carrier-based aircraft is here studied based on the mathematical equations of the classic dual mass spring-damper dynamic *** standards for both take-off and landing performance are put *** contradictory factors between take-off and landing processes are *** optimization of oil in the pin area and the area near the rear oil hole is *** these optimized parameters are used to assess the influence of the initial pressure of the low chamber,the ratio of the high chamber to the low chamber,and the tire inflation pressure on the performance of arresting landing and catapult *** influences of these parameters on carrier-based aircraft and the aircraft-carrier on aircraft catapult take-off is also *** on the results of the simulation,respective take-off criteria must be drafted considering different types of aircraft and different take-off load cases,all of which must be matched to parameters relevant to catapult take-off.

关键词： carrier-based aircraft buffer performance fast-extension performance aircraft design optimization sensitivity analysis

Tracking Performance of Electric Power Steering System Based on the Mixed H_2/H_∞ Strategy

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Chinese Journal of Mechanical Engineering 2011年第4期24卷 584-590页

作者： ZHAO Wanzhong SHI Guobiao LIN Yi nie hong College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China School of Mechanical Engineering Beijing Institute of Technology Beijing 100081 China

The tracking performance of motor current is an important factor that affects the assistance torque of electric power steering （EPS） system. Bad tracking performance will cause assistant torque delay, and make road feeling bad, and is influenced by the input steering torque and system measuring noise. However the existing methods have some shortages on system＇s robust dynamic performance and robust stability. The mixed H2/H∞ strategy for recirculating ball-type EPS system in a pure electric bus is proposed, and vehicle dynamic model of the system is established. Due to the existence of system model uncertainty, disturbance signals, sensor noises and the demand of system dynamic performance, the indexes of robust performance and road feeling for drivers are defined as the appraisal control objectives. The H∞ method is introduced to design the H∞ controller, and the H2 method is applied to optimize the H∞ controller, thus the mixed H2/H∞ controller is designed. The response of EPS system to the motor current command with amplitude of 20 A, the road disturbance with amplitude of 500 N and the sensor random noise with the amplitude of 1 A is simulated. The simulation results show that the recirculating ball-type EPS system with the mixed H2/H∞ controller can attenuate the random noises and disturbances and track the boost curve well, so the mixed H2/H∞ controller can improve the system＇s robust performance and dynamic performance. For the purpose of verifying the performance of the designed control strategy, the motor current tracking performance ground tests are conducted with step response input of the steering wheel, double-lane steering test and lemniscate steering test, respectively. The tests show that the mixed H2/H∞ controller for the recirculating ball-type EPS system of pure electric bus is feasible. The designed controller can solve the robust performance and robust stability of the system, thus improve the tracking performance of the EPS system and provide s

关键词： recirculating ball-type electrical power steering (EPS) system tracking performance mixed H2/H∞

New Model for Calculating Hydrogen Consumption in Residue Hydrotreating

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China Petroleum Processing & Petrochemical Technology 2022年第4期24卷 129-138页

作者： Zhang Kui nie hong Dai Lishun SINOPEC Research Institute of Petroleum Processing Co. Ltd.Beijing 100083China

In this paper,hydrogenation of CH to CH_(2)(HDCH reaction)was employed to simulate the hydrogen consumption during residue hydrotreating,because the pseudo components,CH and CH_(2),can be converted with the content of C and *** a pilot-scale experiment,a kinetic model for the HDCH reaction was constructed and it has high *** analyzing the running data of an industrial-residue hydrotreating unit,the activity change of the HDCH reaction was obtained using the active-region-migration deactivation *** obtained HDCH activity model has high accuracy,where the frequencies of>10%relative errors are less than 1%for the CH and H *** hydrogen consumption model,the coupling of the HDCH kinetic model and the HDCH deactivation model,can be applied to calculate the hydrogen *** case 2,where the hydrogen consumption model is adjusted every 100 days,the calculated data well match the real data compared to case 1,where the hydrogen consumption model is unadjusted over the whole runtime.

关键词： HDCH kinetics deactivation hydrogen-consumption model

Application of a New Catalyst Deactivation Model for Residue Hydrotreating

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China Petroleum Processing & Petrochemical Technology 2021年第2期23卷 11-20页

作者： Zhang Kui nie hong Dai Lishun Research Institute of Petroleum Processing SINOPECBeijing 100083

This article reports a new catalyst deactivation model for residue hydrotreating technology(RHT)with three adjustable parameters,named as“active-region-migration model”.The active-region-migration model is proposed to describe the catalyst deactivation of RHT where the catalysts are deactivated due to metal *** with the lumped reaction kinetics,the deactivation model can be applied to simulate the hydrogenation reaction performance in *** data from a commercial RHT unit show reasonably good agreements with the model ***,the active-region-migration model can separately simulate the catalytic-activity change of each hydrogenation reaction during the whole run of RHT,with a single curve.

关键词： residue hydrotreating hydrodesulfurization kinetic model deactivation model