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Granular material exhibits rich dynamical behaviors under impacting, and its impacting dynamical process is seriously influenced by many factors. The purpose of this paper is to explore the dynamical response of granular bed obliquely impacted by a rotational projectile, and the effect of density ratio and diameter ratio on its penetration depth is mainly considered.

In most experiments, as the angular velocity and the impact velocity always produce a coupling effect on the whole impact process, then it is quite difficult to separately distinguish the influence of angular velocity. Therefore, the discrete element method is used here to achieve this purpose. The authors vary one parameter and keep other parameter unchanged, and then discuss the effect of these parameters on penetration depth statistically.

The numerical model in this paper can effectively predict the dynamical process of granular medium under impacting. The projectile’s penetration depth exhibits a similar scaling with its angular velocity under different density ratios and diameter ratios, and the angular velocity exhibits an obvious criticality.

A DEM code and corresponding statistical approach are used to explore the complex dynamical process of a granular material obliquely impacted by a rotation projectile.

This paper aims to present an attitude determination and control system for a nano‐astrometry satellite which requires precise angular rate control. Focus of the research is methods to achieve the requirement.

In order to obtain astrometry data, the satellite attitude should be controlled to an accuracy of 0.05°. Furthermore, attitude spin rate must be controlled to an accuracy of 4×10⁻⁷ rad/s during observation. In this paper the following unique ideas to achieve these requirements are introduced: magnetic disturbance compensation and rate estimation using star blurred images.

This paper presents the feasibility of a high accurate attitude control system in nano‐ and micro‐satellite missions.

This paper presents a possibility of the application of nano‐satellites to remote‐sensing and astronomy mission, which requires accurate attitude control.

Originalities of the paper are the methods to achieve the high accurate attitude control: magnetic disturbance compensation and angular rate estimation using star images.

This paper presents algorithms for computing the angular velocities of the bodies of a multibody system. A multibody system is any collection of connected bodies. The focus is upon multibody systems consisting of spherically pinned rigid bodies which do not form closed loops. Simple formulae are presented for computing the angular velocities. It is shown that once the angular velocities are known the entire kinematical description and hence, the dynamics of the system, may be developed routinely and in automated fashion. Extension to more general multibody systems follows without conceptual change in the procedures.

The purpose of this study is to solve the problems of poor stability and high energy consumption of the dynamic window algorithm (DWA) for the mobile robots, a novel enhanced dynamic window algorithm is proposed in this paper.

The novel algorithm takes the distance function as the weight of the target-oriented coefficient, and a new evaluation function is presented to optimize the azimuth angle.

The jitter of the mobile robot caused by the drastic change of angular velocity is reduced when the robot is closer to the target point. The simulation results show that the proposed algorithm effectively optimizes the stability of the mobile robot during operation with lower angular velocity dispersion and less energy consumption, but with a slightly higher running time than DWA.

A novel enhanced dynamic window algorithm is proposed and verified. According to the experimental result, the proposed algorithm can reduce the energy consumption of the robot and improves the efficiency of the robot.

This paper aims to describe a novel hybrid inertial measurement unit (IMU) for motion capturing via a new configuration of strategically distributed inertial sensors, and a calibration approach for the accelerometer and gyroscope sensors mounted in a flight vehicle motion tracker built on the inertial navigation system.

The hybrid-IMU is designed with five accelerometers and one auxiliary gyroscope instead of the accelerometer and gyroscope triads in the conventional IMU.

Simulation studies for tracking with both attitude angles and translational movement of a flight vehicle are conducted to illustrate the effectiveness of the proposed method.

The cross-quadratic terms of angular velocity are selected to process the direct measurements of angular velocities of body frame and to avoid the integration of angular acceleration vector compared with gyro-free configuration based on only accelerometers. The inertial sensors are selected from the commercial microelectromechanical system devices to realize its low-cost applications.

This paper aims to present a high-order algorithm implemented with the modal spectral element method and simulations of three-dimensional thermal convective flows by using the full viscous dissipation function in the energy equation. Three benchmark problems were solved to validate the algorithm with exact or theoretical solutions. The heated rotating sphere at different temperatures inside a cold planar Poiseuille flow was simulated parametrically at varied angular velocities with positive and negative rotations.

The fourth-order stiffly stable schemes were implemented and tested for time integration. To provide the hp-refinement and spatial resolution enhancement, a modal spectral element method using hierarchical basis functions was used to solve governing equations in a three-dimensional space.

It was found that the direction of rotation of the heated sphere has totally different effects on drag, lateral force and torque evaluated on surfaces of the sphere and walls. It was further concluded that the angular velocity of the heated sphere has more influence on the wall normal velocity gradient than on the wall normal temperature gradients and therefore, more influence on the viscous dissipation than on the thermal dissipation.

This paper concerns incompressible fluid flow at constant properties with up to medium temperature variations in the absence of thermal radiation and ignoring the pressure work.

This paper contributes a viable high-order algorithm in time and space for modeling convective heat transfer involving an internal heated rotating sphere with the effect of viscous heating.

Results of this paper could provide reference for related topics such as enhanced heat transfer forced convection involving rotating spheres and viscous thermal effect.

The merits include resolving viscous dissipation and thermal diffusion in stationary and rotating boundary layers with both h- and p-type refinements, visualizing the viscous heating effect with the full viscous dissipation function in the energy equation and modeling the forced advection around a rotating sphere with varied positive and negative angular velocities subject to a shear flow.

The objective of the research work is to predict the volume of fluid drained from a cylindrical vessel without entrapping air through the drainpipe, and hence predict the location of the free surface of the liquid in the vessel.

A two‐dimensional axi‐symmetric numerical simulation has been made using a finite volume method that employs unstructured grids with cell‐wise local refinement and an interface capturing scheme to predict the shape of the free surface of water in a cylindrical vessel, thus simulating the entrapment of air in the drainpipe connected to the vessel.

A drain cover was placed on top of the drainpipe to delay the entry of air into the drainpipe. It was found that an increase in the diameter of the drain cover increases the amount of liquid to be drained out before the air could enter into the drainpipe. It was found that air enters the drainpipe at a particular height of the liquid in the vessel. However, when an initial rotational velocity was imparted to the liquid, the height of liquid when air enters the drainpipe depends on the initial bath height. As the initial bath height increases, air enters the drainpipe at a progressively higher bath height. But surprisingly when the drain cover is put in place the initial bath height, again, has no effect on the height of the liquid (in the vessel).

The outcome of the present research work has direct implications for steel making. If the drainpipe can be connected to the ladle the way it has been discussed in this paper then more steel can be drained before stopping the drainage in order to avoid air or slag entrapment.

The idea of putting a drain cover, using a larger diameter drainpipe and making the drainpipe connection to the vessel different so as to delay the appearance of air at the drainpipe is a new finding and the idea can be used by steel makers.

This paper aims to provide tools for the complete Jacobian analysis of robotic manipulators of general topology, using a comprehensive velocity equation.

First, a modelling process is made in order to build the velocity equation using simple constraint equations: i.e. length restriction, relative motion and rigid body constraints. Then the motion space is solved, i.e. the space that spans all feasible motions of the manipulator.

The velocity equation is comprehensive, i.e. it relates all kinematic variables, not only input and output. The Jacobian related to the comprehensive velocity equation is a square dimensionless matrix. This characteristic has great importance when evaluating manipulability or closeness to singularities. Employing the motion space, any kinematic entity can be studied: i.e. velocities and accelerations of any active/passive joints, screw axis, axodes, and so on. Also a comprehensive singularity analysis can be made.

The approach presented is focused on the kinetostatic analysis of manipulators and, therefore, subjected to rigid body assumption.

The paper presents a proposal of effective codes for engineering analysis of manipulators.

This approach is based on a pure computational kinematic analysis that unifies all kinetostatic analysis for any manipulator topology (i.e. serial, parallel, hybrid manipulators, complex mechanisms, redundant‐or non‐redundant‐actuated). The characteristic Jacobian matrix is dimensionless and provides the means for a complete singularity analysis and an effective use of indicators.

THE present paper gives, in abbreviated form, the theory of blade motion and of static and dynamic stability of single‐rotor helicopters. Limitations of space do not permit of full discussion and the article should be taken as only an introduction to the somewhat complex problems of helicopter stability and control.

The purpose of this study is to analyze the impact of inclined magnetohydrodynamics (MHD) and thermal radiation on the flow of a ternary micropolar nanofluid on a sheet that is expanding and contracting while applying mass transpiration and velocity slip conditions to the flow. The nanofluid, which is composed of Au, Ag and Cu nanoparticles dispersed in water as the base fluid, possesses critical properties for increasing the heat transfer rate and is frequently used in manufacturing and industrial establishments.

The set of governing nonlinear partial differential equations is transformed into a set of nonlinear ordinary differential equations. The outcome of this differential equation is solved and obtained the closed-form solution and energy equation in the form of hypergeometric functions.

The velocity, micro-rotation and temperature field are investigated versus a parametric variation. The physical domains of mass suction or injection and micropolar characteristics play an important role in specifying the presence, singleness and multiplanes of exact solutions. In addition, many nondimensional characteristics of the profiles of temperature, angular velocity and velocity profiles are graphically shown with substantial consequences. Furthermore, adding nanoparticles increases the heat transfer rate of the fluid used in manufacturing and industrial establishments. The current findings may be used for better oil recovery procedures, smart materials such as magnetorheological fluids, targeted medicine administration and increased heat transmission. Concerning environmental cleanup, nanomaterial fabrication and biomedical devices, demonstrate their potential influence in a variety of disciplines.

The originality of this paper is to analyze the impact of inclined MHD at an angle with the ternary nanofluid on a micropolar fluid over an expanding and contracting sheet with thermal radiation effect.