Wheel dynamic response to rolling excitation on road

In this paper, tyred wheel dynamic response to road excitation during rolling has been simulated using finite element modelling in a graphical programming environment. The actual contact is an area not a single line and the contact edges are subject to continuous impacts during the rolling. The structural response to the impact generates structure borne noise as part of pollution to the environment. To reduce the wheel noise can be achieved by attenuating the intensity of structural vibration. The relationship between the noise generation energy of wheel and damping is investigated. It is proposed to reduce the noise by increasing the damping in the tyre structure. The effectiveness has been demonstrated by the simulation result

Review on stationary CPT technologies and coil designs for EVs

In the recent decade, the driving range of pure EVs with zero emission target has become a popular topic as the massive battery requirement for longer distance travels means higher vehicle cost and longer time of recharging periods. Stationary CPT charging solutions could be an alternative to reduce EVs weight, size and energy storage unit costs. Fortunately, with progressive success of low-power CPT charging applications proposed to be commercially produced in the past decade, hundreds of kilowatts level high-power CPT charging techniques for EVs are more and more expected to be an optimally suitable solution for recharging EV batteries, providing higher propulsion and delivering continuously longer driving range in the next generations of the EVs. The idea of deploying inductive coupling for EVs has acquired a lot of attentions in the last decade due to the contributions and advancements of power electronics, switching power supply, semiconductors, microprocessors, electrochemistry, material sciences, control technologies, electromagnetics and so on, despite many challenges to be addressed including EV manufacturing integration with CPT system under the chassis, infrastructure difficulties, system maintenance on both vehicle and transmitting ground sides, actual CPT performance with real-time coupling on real-world road. In order to ensure the realization and enhance the sustainability in transportation sector with the emerging CPT ideas, currently the stationary CPT charging solutions based on inductive power transfer (IPT) have been developed from laboratory level as a first step to the practical tests of commercial realizations. In a few industrial fields nowadays, some of the proposed CPT technologies with specific coupler coil designs have been expected for real-world applications. This article presents a state of the art of the CPT technologies and focuses on reviewing current coil designs for high-power contactless energy transfer for EVs in the literature

A comparison of aircraft tire skid with initial wheel rotational speed using ANSYS transient simulation

Based on heavy aircraft main landing gear tires touchdown skidding process, patents have been registered since the 1940s to improve tire safety, decrease the substantial wear and smoke that results from every landing by spinning the rear wheels before touchdown. A single wheel has been modeled as a mass-spring-damper system using ANSYS mechanical transient simulation to analyze static and pre-rotating wheels behavior during a short period between touchdown and skidding, to spin-up to reach the equivalent of the aircraft ground speed. In this paper, a case study is presented of a Boeing 747-400 main landing gear wheel to compare the skidding distance and time between initially static and pre-spun wheels

Design and analysis of a novel CPT system with soft ferromagnetic material cores and electromagnetic resonant coupling for EVs

This paper describes a novel contactless power transfer (CPT) system with geometrically improved H-shape ferromagnetic cores and electromagnetically prospective modelling analysis methods for wireless power transmitting (WPT) applications of electric vehicles (EVs). A CPT prototype, using optimized H-shaped magnetic couplers and series-to-series (SS) compensation, is proposed to address and ensure the maximization of system efficiency, power transfer ratings, and air gaps of coupling coils. By focusing on the main factors such as various system operating frequencies, different geometric designs of coils, changeable inductive coupling distances, electromagnetic field performances and actual phase angle deviations when the inductive coupling system tends to be stable with its waveforms, this small-sized H-shape CPT system has been analytically considered and modelled in a finite-element method (FEM) environment, resulting in a maximum system efficiency of 59.5%, a coil transmitting efficiency of 83.8% and a maximum power output of 42.81 kW on the load end when the resonant coupling of CPT system tends to occur within a range of calculated resonant frequencies, with an air gap of 10 mm. Moreover, the system efficiency and coil transmitting efficiency can reach 47.75% and 77.22%, respectively, and the highest RMS real power to load can achieve 31.95 kW with an air gap of 20 mm. Besides, with an air gap of 30mm, this H-shape CPT system is measured to output 20.39-kW RMS power, along with the maximum system efficiency and coil efficiency of 41.78% and 63.23%, respectively. Furthermore, the improvements of flux linkage, magnetic flux density regarding the actual electromagnetic performance produced and the issues on the calculated natural resonant frequencies have been studied by result analysis and comparison of electromagnetic field parameters generated. In addition, the current limitations and further design considerations have been discussed in this paper

Heat Generation of Aircraft Tires at Landing

When the aircraft lands on a runway, the great speed difference between tires and runway causes non-negligible friction and speeds up wheels. The generated heat rapidly raises tire temperature and causes material decomposition, which leads to replacement cost and flight safety issues; the chemical substances in the air can also cause emission problems. Many studies on aircraft tire temperature are based on software simulation or experiments. The simulation result may be affected by unnecessary variables due to cumbersome modelling, and the observation result may be inaccurate due to a particularly dynamic friction process. On the other side, there are few theoretical calculations about it. Therefore, A dynamic and thermal MATLAB model based on Laplace\u27s heat equation is developed in this study to simulate the tire friction and heat generation. The temperature rise can be treated as an indicator to predict wear under variable landing conditions. The model can also be used to develop tire wear prevention methods

Determination of required torque to spin aircraft wheel at approach using ANSYS CFX

Many patents have suggested that spinning the aircraft wheel before touchdown would lessen tyre wear as indicated by landing smoke and rubber deposites on the runway caused by skidding wheel at the point of impact. In this paper, the required torque to spin the aircraft wheel at approach speed has been calculated using ANSYS Workbench CFX, which is used to determine the wheel aerodynamic forces developed by simulation of fluid flows in a virtual environment. The wheel has been tested against different wind speeds, and the aerodynamic forces for the spinning wheel are presented, which include; translational and rotational drags, lift created by vortex, and shaft rolling resistance

Torque of rotating device prior an airlane landing

This papers focuses on the calculations to understand the torque required to spin the wheel of an airplane before it touches the runway. This measure is part of a proposed solution that is expected to eliminate the smoke generated by the airplane as it lands. The landing smoke is the result of high velocity difference between the landing gear wheels and the runway. Therefore, a slip occurs and causes serve grinding between the tyre and the runway where the tyre happens to be the softer surface. The calculations are based on the assumption that there is a turbine is installed on the side of the wheel

Levenberg-Marquardt optimised neural networks for trajectory tracking of autonomous ground vehicles

Trajectory tracking is an essential capability of robotics operation in industrial automation. In this article, an artificial neural controller is proposed to tackle trajectory-tracking problem of an autonomous ground vehicle (AGV). The controller is implemented based on fractional order proportional integral derivative (FOPID) control that was already designed in an earlier work. A non-holonomic model type of AGV is analysed and presented. The model includes the kinematic, dynamic characteristics and the actuation system of the VGA. The artificial neural controller consists of two artificial neural networks (ANNs) that are designed to control the inputs of the AGV. In order to train the two artificial neural networks, Levenberg-Marquardt (LM) algorithm was used to obtain the parameters of the ANNs. The validation of the proposed controller has been verified through a given reference trajectory. The obtained results show a considerable improvement in term of minimising trajectory tracking error over the FOPID controller

Temperature elevation of aircraft tyre surface at touchdown with pre-rotations

The runway and landing gear speed difference causes non-negligible friction at touchdown, generating vital heat to raise the tyre tread temperature. The resulting material decomposition reduces tread thickness and significantly impacts flight safety and the environment. Airline operators also need to pay the cost of frequent tyre replacement. The pre-rotation strategy has been proposed to prevent high-speed friction at touchdown. Therefore, a mathematical algorithm is established on MATLAB to simulate the tyre friction and heat generation with various pre-rotation levels. The algorithm is validated by experiments, and a transient thermos-mechanical analysis on ANSYS is used as a reference. The presenting work is one of the few that uses theoretical modelling to simulate tyre heat generation. The formulas presented therein, including Laplace's equation, make the results reliable and traceable. It can be seen that the developed algorithm is capable of calculating the tyre temperature. The pre-rotation can efficiently reduce the friction strength at touchdown. However, when the pre-rotation speed is relatively low, a slight increase in maximum tyre temperature may occur, and the specific reasons for this will be in the discussion