scholarly journals Inertial Forces Acting on a Propeller of Aircraft

2018 ◽  
Vol 7 (1) ◽  
pp. 1-13
Author(s):  
R. Usubamatov ◽  
T. Zhumaev
Keyword(s):  
Angular Momentum ◽  
Mathematical Models ◽  
Inertial Forces ◽  
Aerospace Vehicles ◽  
Coriolis Forces ◽  
Rotating Blades ◽  
Variable Resistance ◽  
Combined Action ◽  
The Masses ◽  
Physical Principles

Background:Aerospace vehicles use propellers with the different design that possess gyroscopic properties. Recent investigations in the area of gyroscope theory have demonstrated that the gyroscope properties are based on the action of the centrifugal, common inertial, and Coriolis forces of the distributed mass elements of the spinning rotor, as well as the change in the angular momentum.Objective:The combined action of the interrelated inertial forces on the propellers presents the interests for the design of the blades. The objective of the manuscript is the derivation of mathematical models for the inertial torques acting on the spinning propellers that enable computing the stresses of the blades and increasing their reliability.Method:The inertial torques generated by the masses of the rotating blades acting on the propellers are represented by mathematical models in L. Euler’s form.Results:The inertial torques are generated by the several inertial forces of the propeller’s blades and hub and manifested the fluctuation of the variable resistance and precession torques acting around different axes of the propeller. Derived mathematical models for the inertial torques are new and should be used for the computing forces and stresses acting on the propellers of the aircraft.Conclusion:The mathematical models for the torques acting on the propellers consider the several inertial forces of the rotating masses that manifest their gyroscope properties. Derived mathematical models for inertial torques enable for computing the stresses of the aircraft propellers and clearly demonstrate the physical principles and origin of the acting inertial forces.

scholarly journals Interactions between Rotation and Pulsation

2004 ◽  
Vol 215 ◽  
pp. 404-413
Author(s):  
Rich Townsend
Keyword(s):  
Angular Momentum ◽  
Coriolis Force ◽  
Rossby Waves ◽  
Narrow Band ◽  
Rotating Stars ◽  
Stellar Rotation ◽  
Coriolis Forces ◽  
Wave Dynamics ◽  
Propagating Waves ◽  
Physical Principles

In this contribution, I will examine the interaction between stellar rotation and pulsation. I begin with a brief review of the non-rotating case, emphasizing the character of pulsations as azimuthally-propagating waves. I then go on to discuss how these waves are modified under the influence of the centrifugal and Coriolis forces. Through simple arguments, I outline the conditions under which each force can become significant in determining the wave dynamics. Particular attention is paid to the Coriolis force, since it is responsible for the formation of a waveguide, which confines the pulsation to a narrow band centered on the stellar equator. Using the example of a prograde sectoral pulsation mode, I explain the basic physical principles underlying this trapping.The Coriolis force is also responsible for the existence of Rossby waves, which are not found in non-rotating stars. I demonstrate how these waves may be understood in terms of a conservation law for angular momentum, and review their most important characteristics. I then examine how rotation modifies the frequencies of pulsation, and explain how observations of such modifications can provide information regarding a star's rotation rate. To conclude, I focus on the converse of the pulsation-rotation interaction: how the transport of angular momentum by pulsation might be important in determining the evolution of a star's rotation profile.

scholarly journals A Mathematical Model for Top Nutation Based on Inertial Forces of Distributed Masses

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ryspek Usubamatov ◽  
Albina Omorova
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Angular Momentum ◽  
Mathematical Models ◽  
Vibration Analysis ◽  
Analytical Approach ◽  
Main Property ◽  
Inertial Forces ◽  
Applied Torque ◽  
Dynamics And Vibration

The main property of gyroscopic devices is maintaining the axis of a spinning rotor, a mathematical model formulated on the principle of the change in the angular momentum. This principle is used for mathematical modeling of the motions of a top at known publications. Nevertheless, practical tests of gyroscopic devices do not correspond to this analytical approach. Recent investigations have demonstrated that the origin of gyroscope properties is more complex than that represented in known publications. The applied torque on a gyroscope produces internal torques of the spinning rotor based on the action of the several inertial forces. These forces are the centrifugal, Coriolis, and common inertial forces as well as the change in the angular momentum generated by the mass elements and center-mass of the spinning rotor. The action of these torques manifests itself in the resistance and precession torques of the gyroscopic devices. These inertial torques act simultaneously and interdependently around two axes and represent the fundamental principles of the gyroscope theory. The new inertial torques enable deriving mathematical models for the motions of well-known top that is the simplest form of gyroscopic devices. The novelty of the work is mathematical models for the motions of the top based on action of eight inertial forces acting around its two axes. The obtained mathematical models for the top nutation and self-stabilization are represented in terms of machine dynamics and vibration analysis. The new analytical approach for motions of the well-balanced top and top with eccentricity of the center-mass definitely responds to the practical results.

scholarly journals A Mathematical Model for Top Motions

2019 ◽  
Vol 2 (4) ◽  
Keyword(s):  
Mathematical Model ◽  
Angular Momentum ◽  
Mathematical Models ◽  
Analytical Approach ◽  
Fundamental Principle ◽  
Educational Process ◽  
Coriolis Forces ◽  
Inertial Torque ◽  
Long Time ◽  
Gyroscopic Effects

The topic of the top motions is not new but the known publications represent wrong mathematical models for its gyroscopic effects. Recent investigations have demonstrated the physics of gyroscopic effects is more complex. On any spinning objects are acting the system of interrelated internal torques generated by their rotating mass elements and center mass. The inertial torque is produced by the centrifugal, common inertial and Coriolis forces, as well as the change in the angular momentum. These inertial torqueses represent the fundamental principle of gyroscope theory. The new inertial torques enables deriving mathematical models for the motions of any rotating objects that were impossible for a long time. The aim of this work is to represent mathematical models for the motions of the well-balanced top on the flat horizontal surface. This work describes the physics of the top motions and closes the problem of many years of discussion. The new analytical approach for the top’s motions definitely responds to the practical results and represents a good example of the educational process.

scholarly journals Current-induced spin–orbit torques

2011 ◽  
Vol 369 (1948) ◽  
pp. 3175-3197 ◽  
Author(s):  
Pietro Gambardella ◽  
Ioan Mihai Miron
Keyword(s):  
Angular Momentum ◽  
Exchange Coupling ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Torque ◽  
Inversion Symmetry ◽  
Spin Orbit ◽  
Great Flexibility ◽  
Combined Action ◽  
Proper Material

The ability to reverse the magnetization of nanomagnets by current injection has attracted increased attention ever since the spin-transfer torque mechanism was predicted in 1996. In this paper, we review the basic theoretical and experimental arguments supporting a novel current-induced spin torque mechanism taking place in ferromagnetic (FM) materials. This effect, hereafter named spin–orbit (SO) torque, is produced by the flow of an electric current in a crystalline structure lacking inversion symmetry, which transfers orbital angular momentum from the lattice to the spin system owing to the combined action of SO and exchange coupling. SO torques are found to be prominent in both FM metal and semiconducting systems, allowing for great flexibility in adjusting their orientation and magnitude by proper material engineering. Further directions of research in this field are briefly outlined.

scholarly journals The concept of creating thrust based on angular momentum change

2021 ◽  
Author(s):  
Sergei Kupreev
Keyword(s):  
Angular Momentum ◽  
Vacuum Chamber ◽  
Loop Quantum Gravity ◽  
Low Energy ◽  
Practical Implementation ◽  
Material Body ◽  
The World ◽  
Classical And Quantum Mechanics ◽  
Physical Principles ◽  
Kinetic Moment

Abstract The change in the kinetic moment of a material body is considered regarding to classical and quantum mechanics. The possibility of creating the propulsion system in terms of energy efficiency exceeding the photon engine has been theoretically proved. The proposed new principle of motion is based on the law of conservation of angular momentum and is fully consistent with the basic fundamental laws of physics. It is proposed to use the emission/absorption of streams of low-energy particles with spin in the direction perpendicular to the movement of the material body. The practical implementation of this idea is confirmed by the presence of promising approaches to solving the problem of quantizing gravity (string theory, loop quantum gravity, etc.) recognized by the world scientific community and by the successful results of experiments conducted by the authors with the motion of bodies in a vacuum chamber. The proposed idea, the examples and experiments has given grounds for the formation of new physical concepts of the speed, mass and inertia of bodies. The obtained results can be used in experiments to search for elementary particles with low energy, to explain a number of physics phenomena and to develop transport of objects based on new physical principles.

Star formation in a galactic cluster

1979 ◽  
Vol 291 (1380) ◽  
pp. 219-252 ◽  
Keyword(s):  
Angular Momentum ◽  
Star Formation ◽  
Differential Equations ◽  
Theoretical Prediction ◽  
Massive Stars ◽  
Planetary Systems ◽  
Interstellar Cloud ◽  
Dissipation Of Energy ◽  
Galactic Cluster ◽  
The Masses

A model has been developed for the collapse of an interstellar cloud with turbulence. The differential equations which describe the evolution of the cloud include ionic and dust cooling and also the dissipation of energy due to the collision of turbulent elements moving at supersonic speeds. Under some conditions the collision of two elements can give rise to a star and the rate of star formation and the mass of the stars formed changes as the cloud collapses. The pattern found is that the stars first produced have masses of about 1.4 M . and the masses get less as star formation continues. Stars produced by this mechanism have little associated angular momentum. Some of the stars which happen to move in high density regions of the cloud may increase their mass greatly by accretion; these stars will be the more massive stars and they will also rotate most rapidly, a theoretical prediction which agrees with observation. On the basis of the model the proportion of stars which would have planetary systems is estimated. This shows that there should be of order 10 6 planetary systems per galaxy.

scholarly journals Analytical model for computing translational and rotational angular momentum occurring in treadmill walking

2019 ◽  
Vol 29 ◽  
pp. 02010
Author(s):  
Dan Ioan Stoia ◽  
Alin-Florin Totorean
Keyword(s):  
Angular Momentum ◽  
Analytical Model ◽  
Lower Limb ◽  
Total Body Weight ◽  
Treadmill Walking ◽  
Lower Limbs ◽  
Human Gait ◽  
Dynamical Parameters ◽  
The Masses ◽  
Rotational Angular Momentum

The kinematical modifications of human gait associated with treadmill walking are well studied in the literature. Fewer researches are focusing on computing the dynamical parameters of the gait, in this particular situation. Starting from kinematical data recorded in treadmill walking, the paper proposes an analytical model of the lower limbs that allows computation of translational and rotational angular momentum for each segment. The experimental data used in the study were recorded using ultrasound based, 3D motion equipment. By mean of this system, relative and absolute angles of the lower limb can be computed using Cartesian coordinates of each anatomical landmark. The velocities and accelerations were obtained by numerical derivative. In order to compute the dynamical parameters, segment masses and inertias were collected from the literature. The masses are based on percentage of total body weight while the segment inertias are based on geometrical characteristics of lower limb segments.

scholarly journals High-Efficiency Small Sample Microparticle Fractionation on a Femtosecond Laser-Machined Microfluidic Disc

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 151
Author(s):  
Ala’aldeen Al-Halhouli ◽  
Zaid Doofesh ◽  
Ahmed Albagdady ◽  
Andreas Dietzel
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
High Efficiency ◽  
Femtosecond Laser Ablation ◽  
Small Sample ◽  
Inertial Forces ◽  
Inertial Focusing ◽  
Coriolis Forces ◽  
Disc Rotation ◽  
First Time

The fabrication and testing of microfluidic spinning compact discs with embedded trapezoidal microchambers for the purpose of inertial microparticle focusing is reported in this article. Microparticle focusing channels require small features that cannot be easily fabricated in acrylic sheets and are complicated to realize in glass by traditional lithography techniques; therefore, the fabrication of microfluidic discs with femtosecond laser ablation is reported for the first time in this paper. It could be demonstrated that high-efficiency inertial focusing of 5 and 10 µm particles is achieved in a channel with trapezoidal microchambers regardless of the direction of disc rotation, which correlates to the dominance of inertial forces over Coriolis forces. To achieve the highest throughput possible, the suspension concentration was increased from 0.001% (w/v) to 0.005% (w/v). The focusing efficiency was 98.7% for the 10 µm particles and 93.75% for the 5 µm particles.

scholarly journals Accretion of Protobinary and Evolution of the Mass Ratio

2004 ◽  
Vol 191 ◽  
pp. 163-167
Author(s):  
Tomoyuki Hanawa ◽  
Yasuhiro Ochi ◽  
Kanako Sugimoto
Keyword(s):  
Angular Momentum ◽  
Surface Density ◽  
Accretion Rate ◽  
Orbital Plane ◽  
Gas Flows ◽  
Lagrangian Point ◽  
Mass Ratio ◽  
Fall Velocity ◽  
Rotation Periods ◽  
The Masses

AbstractWe have reexamined accretion in a protobinary system with two dimensional numerical simulations. We consider protostars which rotate around the center of the mass with circular orbits. The accreting gas is assumed to flow in the orbital plane. It is injected from a circle whose radius is 5 times larger than the orbital separation of the binary. The injected gas has constant surface density, in fall velocity, and specific angular momentum. The accretion depends on the specific angular momentum of the injected gas, jinf. When jinf is small, the binary accretes the gas mainly through two channels: one through the Lagrangian point L2 and the other through L3. When jinf is large, the binary accretes the gas only through the L2 point. The primary accretes more than the secondary in both cases, although the L2 point is closer to the secondary. After flowing through the L2 point, the gas flows half around the secondary and through the L1 point to the primary. Only a small amount of gas flows back to the secondary and the rest forms a circumstellar ring around the primary. The accretion decreases the mass ratio, q = M2/M1, where M1 and M2 denote the masses of the primary and secondary, respectively. The accretion rate increases with time. When jinf is large, it is negligibly small in the first few rotation periods.

scholarly journals Equations of motion of masses of the Chelomey pendulum model

2021 ◽  
Author(s):  
N. Kryshchuk ◽  
A. Tsybenko ◽  
Y. Lavrenko ◽  
A. Oleshchuk A.
Keyword(s):  
Software Package ◽  
Numerical Solutions ◽  
Equations Of Motion ◽  
Newtonian Mechanics ◽  
Inertial Forces ◽  
Pendulum Model ◽  
Unit Work ◽  
Conservation Of Momentum ◽  
Mathcad Software ◽  
The Masses

Abstract. To verify the provisions stated by V.I. Bogomolov, B.I. Puzanov. and Linevich E.I. about the possibility of performing over-unit work by inertial forces, a closed mechanical system in the form of kinematically connected rotating masses is proposed for consideration. The research aimed, within the framework of Newtonian mechanics, to study the fulfillment of the laws of conservation of momentum, angular momentum and energy, to establish the possibility of performing work by inertial forces (centrifugal and Coriolis), to assess the change in kinetic parameters using the example of the Chelomey pendulum model. For the complex radial-circular motion of the masses of the Chelomey pendulum model, resolving equations are obtained. To verify the analytical calculations, algorithms for numerical solutions of the above problems have been developed and implemented in the MathCAD software package.

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