Study on the Dynamics of a Rotor in a Maneuvering Aircraft

2003 ◽  
Vol 125 (3) ◽  
pp. 324-327 ◽  
Author(s):  
Fusheng Lin ◽  
Guang Meng
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Vertical Plane ◽  
Angular Speed ◽  
Rotor System ◽  
Flight Path ◽  
Constant Acceleration ◽  
Unbalanced Rotor ◽  
The Mathematical Model

This paper shows how the dynamics of a rotor in a maneuvering aircraft changes according to the operation of the aircraft. The mathematical model of an unbalanced rotor system located in the maneuvering aircraft is derived. The dynamic characteristics of the rotor running at a constant angular speed or a constant acceleration are studied under the assumptions that the aircraft maneuvers only in a vertical plane and that the pitching angle and the flight path inclination of the aircraft are equal. The effects of gravity and unbalance parameter are considered. The results show that the unbalanced response of a rotor in an aircraft is obviously influenced by the aircraft’s flying status.

scholarly journals Determination of the Vertical Load on the Carrying Structure of a Flat Wagon with the 18–100 and Y25 Bogies

2021 ◽  
Vol 11 (9) ◽  
pp. 4130
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska ◽  
Václav Píštěk ◽  
Pavel Kučera
Keyword(s):  
Mathematical Model ◽  
Fatigue Strength ◽  
Service Life ◽  
Dynamic Characteristics ◽  
Dynamic Load ◽  
Field Tests ◽  
Vertical Load ◽  
Mathcad Software ◽  
The Mathematical Model

The study deals with determination of the vertical load on the carrying structure of a flat wagon on the 18–100 and Y25 bogies using mathematic modelling. The study was made for an empty wagon passing over a joint irregularity. The authors calculated the carrying structure of a flat wagon with the designed parameters and the actual features recorded during field tests. The mathematical model was solved in MathCad software. The study found that application of the Y25 bogie for a flat wagon with the designed parameters can decrease the dynamic load by 41.1% in comparison to that with the 18–100 bogie. Therefore, application of the Y25 bogie under a flat wagon with the actual parameters allows decreasing the dynamic loading by 41.4% in comparison to that with the 18–100 bogie. The study also looks at the service life of the supporting structure of a flat wagon with the Y25 bogie, which can be more than twice as long as the 18–100 bogie. The research can be of interest for specialists concerned with improvements in the dynamic characteristics and the fatigue strength of freight cars, safe rail operation, freight security, and the results of the research can be used for development of innovative wagon structures.

scholarly journals Engineering of Light Electric Commercial Vehicle

2020 ◽  
Vol 19 (1) ◽  
pp. 63-75
Author(s):  
R. Dorofeev ◽  
A. Tumasov ◽  
A. Sizov ◽  
A. Kocherov ◽  
A. Meshkov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Electric Vehicle ◽  
Electric Motor ◽  
Field Tests ◽  
Angular Speed ◽  
Maximum Energy ◽  
Driving Cycle ◽  
Thermal Calculation ◽  
Technical Solutions ◽  
The Mathematical Model

The paper describes the process and results of the development of the light commercial electric vehicle. In order to ensure maximum energy efficiency of the developed vehicle the key parameters of the original electric motor. The article also presents the results of power electronic thermal calculation. For the mathematical model of the vehicle, the driving cycle parameters of the electric platform were determined in accordance with UNECE Regulations No 83, 84. The driving cycle was characterized by four successive urban and suburban cycles. The mathematical model also takes into account the time phases of the cycle, which include idling, vehicle idling, acceleration, constant speed movement, deceleration, etc. The model of the electric part of the vehicle was developed using MatLab-Simulink (SimPowerSystems library) in addition to the mechanical part of the electric car. The electric part included the asynchronous electric motor, the motor control system and the inverter. This model at the output allows to obtain such characteristics of the electric motor as currents, flows and voltages of the stator and rotor in a fixed and rotating coordinate systems, electromagnetic moment, angular speed of rotation of the motor shaft. The developed model allowed to calculate and evaluate the performance parameters of the electric vehicle. Technical solutions of the electric vehicle design were verified by conducting strength calculations. In conclusion, the results of field tests of a commercial electric vehicle are presented.

The static and dynamic characteristics of a pressure relief valve with a proportional solenoid-controlled pilot stage

2002 ◽  
Vol 216 (2) ◽  
pp. 143-156 ◽  
Author(s):  
R Maiti ◽  
R Saha ◽  
J Watton
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Dynamic Behaviour ◽  
Practical Experience ◽  
Pressure Relief Valve ◽  
Relief Valve ◽  
Pressure Relief ◽  
Static And Dynamic Characteristics ◽  
Good Comparison ◽  
The Mathematical Model

The steady state and dynamic characteristics of a two-stage pressure relief valve with proportional solenoid control of the pilot stage is studied theoretically as well as experimentally. The mathematical model is studied within the MATLAB-SIMULINK environment and the non-linearities have been considered via the use of appropriate SIMULINK blocks. The detailed modelling has resulted in a good comparison between simulation and measurement, albeit assumptions had to be made regarding the solenoid dynamic characteristic based upon practical experience. The use of this characteristic combined with additional dynamic terms not previously considered allows new estimations of internal characteristics to be made such as the damping flowrate. The overall dynamic behaviour has been shown to be dominated by the solenoid characteristic relating force to applied voltage.

Exact Solutions of the Vibration Problem of Beam Structures

2013 ◽  
Vol 390 ◽  
pp. 242-245 ◽  
Author(s):  
Alexander V. Chekanin
Keyword(s):  
Mathematical Model ◽  
Exact Solutions ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Numerical Solutions ◽  
High Accuracy ◽  
Displacement Method ◽  
Actual Problem ◽  
Beam Structures ◽  
The Mathematical Model

The article deals with the actual problem of improving the accuracy of determining the dynamic characteristics of beam structures. To solve such problems the displacement method is used. Defining matrices are calculated with the Godunovs scheme. Numerical solutions in this case can be obtained practically with any accuracy within accepted hypotheses of the mathematical model of the calculated object. This suggests that the resulting solutions are standard. The examples of determining the natural frequencies of vibrations of beam structures that demonstrate an extremely high accuracy of the proposed algorithm are given.

Influence Characteristics of Fluid Film Bearing’s Displacement-Load on Rotating Vibration of Rotor System

2015 ◽  
Vol 727-728 ◽  
pp. 567-571
Author(s):  
Xi Chen Lin ◽  
Rui Ping Zhou ◽  
Neng Qi Xiao
Keyword(s):  
Mathematical Model ◽  
Numerical Integration ◽  
Dynamic Characteristics ◽  
Load Distribution ◽  
High Load ◽  
Rotor System ◽  
Vibration Response ◽  
Fluid Film ◽  
Load Carrying

In high load-carrying bearing-rotor system, bearings’ places usually change for load distribution or in continual work. It influences the system’s stability, and brings out different vibration response in rotor system. This article puts forward mathematical model of bearing’s stiffness under load which is calculated from bearing displacement. Then through numerical integration it studies system’s rotating vibration with different bearing settings. The results of the analysis show that bearing displacement has a great effect on dynamic characteristics of the bearing-rotor system.

Study on Control Characteristics of Driving and Lifting System for Logistics and Loading Machinery

2012 ◽  
Vol 268-270 ◽  
pp. 1517-1522 ◽  
Author(s):  
Guo Jin Chen ◽  
Ting Ting Liu ◽  
Ni Jin ◽  
You Ping Gong ◽  
Huo Qing Feng
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Optimization Design ◽  
Integrated System ◽  
Operating Conditions ◽  
Control Methods ◽  
Lifting System ◽  
The Mathematical Model ◽  
Power Match

The logistics and loading machinery is the typical hydromechatronics integrated system. How to solve the reasonable power match in the driving and lifting process of the logistics and loading machinery, we need to establish the mathematical model of the driving and lifting system, and analyze their control characteristics. Aiming at the load requirements for different operating conditions, this paper studies respectively the dynamic characteristics of the driving and lifting system. Through simulation and computation, the control methods and strategies based on the best performance are proposed. That lays the foundation for the optimization design of the logistics and loading machinery.

scholarly journals Mathematical Model of Spatial Motion of the Controlled Parachute-Tether System of the Wind Kite Type

2021 ◽  
Vol 24 (4) ◽  
pp. 17-24
Author(s):  
V.M. Churkin ◽  
T.Yu. Churkina ◽  
A.M. Girin
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Solid Body ◽  
Equations Of Motion ◽  
Vertical Plane ◽  
Spatial Motion ◽  
Mathematical Task ◽  
Spatial Movement ◽  
Elastic Thread ◽  
The Mathematical Model

Mathematical modeling is created for the mathematical task of spatial motion of the controlled parachute-tether system of the “wind kite” type. The mathematical model parachute-tether system consists of a model of the main parachute and a model of the braking parachute. The parachutes are connected by the tether. The model of the main parachute is supposed to be the solid body. This solid body has two planes of symmetry. The braking parachute is the solid body with axial symmetry. The tether model is an absolutely flexible elastic thread. The tether is connected by ideal hinges with the main parachute and braking parachute. The control of the main parachute is carried out by changing the length of the control slings. Changing the length causes deformation of the dome. This is the reason for the change in its aerodynamics. Maneuvering of the main parachute occurs in the vertical plane, when the length of the control slings changes simultaneously. Maneuvering of the main parachute in space is carried out when the length of the control slings changes, when the slings are given a travel difference. The system of dynamic and kinematic equations is designed for calculating the controlled spatial movement of the main parachute, braking parachute and tether. The option exists when the mass of the tether and the forces applied to the tether cannot be neglected. The motion of the tether is represented by the equations of motion of an absolutely flexible elastic thread in projections on the axis of a natural trihedron. The mathematical model is represented by a system of ordinary differential equations and partial differential equations. The problem is solved using various numerical methods. The solution is possible with the help of an integrated numerical and analytical approach as well.

scholarly journals Improving the Dynamic Characteristics of Precision Lathes Used in the Repair of Agricultural Machinery

2021 ◽  
pp. 36-39
Author(s):  
D.E. Molochnikov ◽  
◽  
R.Sh. Halimov ◽  
N.P. Ayugin ◽  
I.R. Salakhutdinov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Low Frequency ◽  
Frequency Component ◽  
Honeycomb Structure ◽  
Friction Unit ◽  
Agricultural Machinery ◽  
Longitudinal Vibrations ◽  
Model Of Friction ◽  
The Mathematical Model

A model of a friction unit of a lathe in the form of a thin layer of material of a honeycomb structure is described to determine the dynamic characteristics of a movable carriage to guide joint. The analysis of the mathematical model of friction for different sliding pairs with varying load and sliding speed is performed. It is shown that the presence of an abrasive impurity in the lubrication of the guide enhances the effect of the low-frequency component of the carriage vibrations on the dynamics of the machine tool and the presence of pockets for retaining the lubricant in the joint of the guide makes it possible to reduce the amplitude of the longitudinal vibrations of the carriage to 30-50 %.

Mathematical modeling of articulated passenger train spatial vibrations

2021 ◽  
Vol 2021 (2) ◽  
pp. 91-99
Author(s):  
O. Markova ◽  
◽  
H. Kovtun ◽  
V. Maliy ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Ride Quality ◽  
Railway Transport ◽  
Passenger Train ◽  
Wide Range ◽  
Random Track Irregularities ◽  
The Mathematical Model

The problem of high-speed railway transport development is important for Ukraine. In many countries articulated trains are used for this purpose. As the connections between cars in such a train differ from each other, to investigate its dynamic characteristics not a separate car, but a full train vibrations model is necessary. The article is devoted to the development of the mathematical model for articulated passenger train spatial vibrations. The considered train consists of 7 cars: one motor-car, one transitional car, three articulated cars, one more transitional car and again one motor-car. Differential equations of the train motion along the track of arbitrary shape are set in the form of Lagrange’s equations of the second kind. All the necessary design features of the vehicles are taken into account. Articulated cars have common bogies with adjoining cars and a transfer car and the cars are united by the hinge. The operation of the central hinge between two cars is modeled using springs and dampers acting in the horizontal and vertical directions. Four dampers between two adjacent car-bodies act as dampers for pitching and hunting and are represented in the model by viscous damping. The system of 257 differential equations of the second order is set, which describes the articulated train motion along straight, curved, and transitional track segments with taking into account random track irregularities. On the basis of the obtained mathematical model the algorithm and computational software has been developed to simulate a wide range of cases including all possible combinations of parameters for the train elements and track technical state. The study of the train self-exited vibrations has shown the stable motion in all the range of the considered speeds (40 km/h – 180 km/h). The results obtained at the train motion along the track maintained for the speedy motion have shown that all the dynamic characteristics and ride quality index insure train safe motion and comfortable conditions for the travelling passengers.

Study on Dynamic Characteristics and Dynamic Response of Woodworking Four-Side Planer

2011 ◽  
Vol 291-294 ◽  
pp. 1970-1976
Author(s):  
Shao Qun Zhang ◽  
Jun Hua ◽  
Wei Xu
Keyword(s):  
Mathematical Model ◽  
Dynamic Response ◽  
Natural Frequency ◽  
Dynamic Characteristics ◽  
Feed Rate ◽  
Reference Data ◽  
Damping Ratio ◽  
Vibration Test ◽  
Vibration Magnitude ◽  
The Mathematical Model

Through woodworking four-side planer vibration test, this article studiesits dynamic characteristics and dynamic response to identify the vibration magnitudes law of each feed roll shafts of the four-side feed beam; then finds the natural frequency and damping ratio of the feed beam and lathe bed; obtains the mathematical model of feed roll shaft vibration magnitude changing with the feed rate U under different process thicknesses. The analysis of feeding quantity and the rationality of lathe bed from the perspective of vibration design supplies the designs and operation staff with reference data.

Sign in / Sign up

Export Citation Format

Share Document