Variable Moment Of Inertia Research Articles

Improving Rotational Stability and Enhancing Efficiency with Variable Inertial Flywheels and Magneto-rheological Fluids

Variations in the rotational speed of a flywheel are naturally resisted by the moment of inertia. A high moment of inertia must be maintained to minimize angular velocity variations. Conversely, a significant moment of inertia makes it difficult to start spinning machines. A flywheel with a variable moment of inertia has been suggested to solve this issue. Although fluctuations between the masses' radii across the flywheel's axis may be used to approximate true inertia, the variable inertial flywheel's (VIF) control mechanisms are somewhat complex. Magneto-rheological (MR) Fluids can be utilized to avoid the complexity of the VIF. The applied device parameters determine the design and construction of the VIF system using a relatively simple control technique. To determine the relation between the semi-active VIF control system and the input parameters of a rotating electrical machine to decrease energy losses, adequate data from a VIF coupled with an induction motor (IM) system is gathered in this study. An analysis was done on the system, and the outcome showed a possible improvement in the performance of IM. This study significantly reduces power consumption and smooth speed build-up possibility for the proposed system.

Controlling the Variable Inertia of Flywheel: A Scientific Review

Due to the variation of the moment of inertia, flywheels, a well-known mechanical system, can balance the energy output by preventing fluctuations in rotational speed. Examples of prevalent applications are the engine with internal combustion and industrial apparatus. A flywheel with a considerable moment of inertia is mandatory to accomplish reduced angular velocity variations. A flywheel with a variable moment of inertia can be recommended for specific applications to obtain sustainable energy savings. Variations in the masses' radii from the flywheel axis can yield the concept of true inertia. Still, the control techniques for the variable inertial flywheel (VIF) are relatively complex. This paper critically analyses the available literature on VIF control methods and focuses on their application.

Description of moment of inertia and the interplay between anti-pairing and pairing correlations in 244Pu and 248Cm* *Xiao-Tao He Supported by the the National Key R and D Program of China (2023YFA1606503)

A variable moment of inertia (VMI) inspired interacting boson model (IBM), which includes many-body interactions and a perturbation possessing (5) (or (5)) symmetry, is used to investigate the rotational bands of the mass region. A novel modification is introduced, extending the Arima coefficient to the third order. This study is dedicated to the quantitative analysis of evolving trends in intraband γ-transition energy as well as the kinematic and dynamic moments of inertia (MoIs) within the rotational bands of Pu and Cm. The computed outcomes exhibit an exceptional degree of agreement with experimental observations across various conditions. The significance of including a higher-order Arima coefficient is further examined by contrasting it with the previously proposed model. The calculated results demonstrate the significance of both the anti-pairing and pairing effects in the evolution of the dynamic MoI. Additionally, these insights reveal the importance of a newly introduced parameter in accurately depicting complex nuclear behaviors, such as back-bending, up-bending, and downturn in the MoI.

INCREASE IN THE WEIGHT EFFICIENCY OF A DRIVE WITH A VARIABLE MOMENT OF INERTIA PULLEY

When designing a cable car drive with a variable moment of inertia, the greatest attention was paid to the pulley of the variable moment of inertia. Therefore, the sizes of some parts and nodes were accepted "by the eye" in compliance with the condition of strength. This has led to an overestimation of the strength of the strength and, as a consequence, to an increase in the mass of the whole drive. Reducing the dimensions of the parts will reduce the weight and reduce their cost. The purpose of the work is to substantiate the geometric parameters of the drive from the pulley of the variable moment of inertia, in which its weight and material consumption may be reduced. The optimization of geometric dimensions will be made using the Solidworks automated modeling and design system using SW Simulation.

Influence of Non-Uniform Rail Loads on the Rotation of Railway Sleepers

This article presents an innovative, two-stage railway track model, which takes into consideration the rotation of railway sleepers due to non-uniform loads on rails. Examples of determining the dynamic response of the railway track are provided. The calculations were performed for a curve, in which non-uniform loads on rails result from the distribution of vertical loads at different train speeds. The analysis was performed using a variable moment of inertia of a sleeper.

Selection of reference model for adaptive PMSM drive based on MRAC approach

The selection of a reference model (RM) for a Model-Reference Adaptive Control is one of the most important aspects of the synthesis process of the adaptive control system. In this paper, the four different implementations of RM are developed and investigated in an adaptive PMSM drive with variable moment of inertia. Adaptation mechanisms are based on the Widrow-Hoff rule (W-H) and the Adaptation Procedure for Optimization Algorithms (APOA). Inadequate order or inaccurate approximation of RM for the W-H rule may provide poor behavior and oscillations. The results prove that APOA is robust against an improper selection of RM and provides high-performance PMSM drive operation.

An implementation of inertia control strategy for grid-connected solar system using moth-flame optimization algorithm

As the solar power system power system grows rapidly, inertia control strategy (ICS) becomes crucial to enable stable grid integration. However, the existing ICS lacks of dynamic weather analysis with maximum power point tracking (MPPT) and fault-ride through (FRT) capabilities such as low voltage ride-through (LVRT) and high voltage ride-through (HVRT). In this work, an inertia weighting strategy and the Cauchy mutation operator are introduced to improve the moth-flame optimization (MFO) algorithm to support vector machine prediction of photovoltaic power generation. In this paper, the proposed adaptive VICS with variable moment of inertia (J) and damping factor ( D P ) demonstrates its effectiveness with faster frequency recovery, less overshooting and continuous stable operation under grid fault and dynamic weather. The MFO algorithm is used to implement inertia control strategies for grid-connected solar systems. Accurate simulation results confirm the inertia control of the emulsion and the control of the solar system. The results of the simulation show a significant improvement in frequency with the designed MFO and compared to Horse Herd Optimization (HHO). The proposed method contributes to improve photovoltaic energy prediction, reduces the impact of photovoltaic power penetration into the grid and maintains the system reliability.

Performance Validation of Resonant Wave Power Converter with Variable Moment of Inertia

This study focuses on the performance validation of a wave energy converter (WEC) equipped with resonant frequency adjustment capability. Achieving resonance with the oscillation period of waves is crucial for maximizing the efficiency of wave energy conversion systems. For this purpose, we introduce a variable moment of inertia (VMI) device that allows for tuning of the resonant frequency by adjusting the position of the mass. For validation of the proposed approach, performance verification experiments were conducted using a vibration platform. Through free vibration experiments, we identified the system’s resonant frequency and characteristics. In our forced vibration tests considering the wave frequency band of the coastal area, harmonic vibration experiments were performed over a range of 0.4–0.8 Hz. In these experiments, we considered three separate cases by adjusting the distance from the reel’s center to the mass. As a result, we found that the resonant frequency of the WEC can be adjusted from 0.65 Hz when the mass is furthest away to 0.55 Hz when it is closer. This research confirms the benefits obtained by utilizing VMI to adjust the resonant frequency of WECs without changing the mass or springs. This offers a promising opportunity to enhance the energy conversion efficiency of resonant-type WECs utilizing wave energy.

Search for Super-Deformed Identical Bands in the A = 190 Mass Region on the Basis of Level Spin

The systematic study of Super-Deformed (SD) bands in the A=190 mass region has been performed. We observed a large number of pairs of SD bands, with different mass numbers, having transition energies nearly equal (within 3 keV) and having identical dynamic moments of inertia. The bands having nearly equal transitions energies and other parameters are called identical bands. We have performed detailed analysis and found 16 pairs of Super-Deformed Identical Bands (SDIBs) whose Eγ energies and moment of inertia are in good agreement with each other. The modified Variable Moment of Inertia (VMI) model is applied to 16 pairs of SDIBs to estimate the band spins by fitting the two parameters J0 and C. We found that out of 16 pairs, the band-head spin is consistent with moment of inertia and transition energies for four pairs. For another seven pairs, the transition energies and moment of inertia are identical, but originate from levels with different spins. The remaining five pairs have the identical energy but spins are either increasing or decreasing by one unit in the pair. Secondly, the NpNn scheme is applied to verify the existence of SDIBs. The parameters deduced from the NpNn scheme are also in good agreement for the mentioned case. The study indicates that each pair of conjugate nuclei have nearly identical spin, moment of inertia (dynamic) and gamma transition energy.

Describe of Nuclear Structure for Germanium (_32^66)Ge_34) Nucleus under frame (IBM-1, GVMI and VMI) Models

In this paper, the interacting bosons model-1 (IBM-1), a variable moment of inertia (VMI) and generalized moment of inertia (GVMI) models were used to calculate the energy levels of the positive parity and its gamma transitions as a function of the angular momentum of even-even (_32^66Ge_34) nucleus. To determine the dynamic symmetry of this nucleus, the ratios of the energy levels (E_4^+)⁄(E_2^+ ), (E_6^+)⁄(E_2^+), and (E_8^+)⁄(E_2^+) were evaluated and compared with experimental energy values and the ideal scheme of the three dynamic symmetries SU(5), SU(3), and O(6). The current study showed that the dynamic symmetry of this nucleus is determined to be O(6) - SU(5). The intersection of the energy band and the phenomenon of back bending were also studied using the (VMI) and (GVMI) models. These consequences were compared with the experimental results, and the results obtained have been in good agreement.

Theoretical Description of even- even Platinum Pt-186 nucleus using IBM and (VMI) Models

The aim of this study, is to investigate, in a phenomenological way, the backbending effect in platinum Pt-186 nucleus, in order to get a good description of the bends by using new parameters. VMI model and interacting boson model IBM-1 have been used to perform this research for a heavy mass nucleus (Z = 78). Energy ratios and arrangement of the bands show that the platinum Pt-186 have O(6)-SU(3) dynamical symmetry. Our current calculations gave results that are reasonably consistent with the most recent experimental data, especially the results calculated according to the VMI-model. Variable moment of inertia has been applied to describe successfully the effect of backbending in deformed even-even Pt-186 nucleus. Backbending was observed in the ground and β-bands, due to the change of the moment of inertia but not for (γ1, γ2 bands, because no changing in the moment of inertia.

Investigation of the Free-Fall Dynamic Behavior of a Rectangular Wing with Variable Center of Mass Location and Variable Moment of Inertia

In recent years, the air-drop launch technology of near-space UAVs has attracted much attention. Between downfall from the carrier and the flight control system’s initiation, the UAV presents free-fall movement. This free-fall process is very important for the control effect of the flight control system and is also crucial for the safety of the UAV and the carrier. Focus is required on two important dynamic parameters of the UAV: the moment of inertia and the center of mass position. In this paper, we used a quasi-steady model proposed by predecessors to address the flat-plate falling problem with modifications to describe the freely falling motion of the wing. Computational fluid dynamics (CFD) were used to simulate the free-fall movement of the wing with various parameters, and the wing release behavior was analyzed to check the quasi-steady model. Research shows that the movement characteristics of the falling wing are mostly reflected in the longitudinal plane, and the developed quasi-steady analytical model can more accurately describe the dynamic behavior of free-fall to some extent. By using CFD methods, we further investigated the aerodynamic performance of the free-fall wing. The results show that the wing mainly presents tumbling and fluttering motion. Changing the moment of inertia around the tumbling axis changes the tumbling frequency and the time point as the wing enters tumbling. In contrast, changing the position of the center of mass significantly changes the form of falling and makes the free-fall motion more complex. Therefore, it is necessary to carefully configure the center of mass in the UAV design process.

Analysis of super-deformed bands in A∼150 mass region: The principal-axis cranking versus the variable moment of inertia

A systematic study of the super-deformed (SD) bands in [Formula: see text] mass region is carried out by using two different approaches, namely, the Principal-axis Cranking (PAC) and the Variable Moment of Inertia (VMI). Both these approaches not only support each other’s results but also their hand-in-hand calculations help us in establishing the prominent features, like the band-head spin, parity, quadrupole moment and excitation energy, of the observed SD bands. Since the rotational frequency in the PAC model depends on angular momentum, parity, and quadrupole moment, by identifying the most common rotational frequency between the calculations and the experimentally observed ones, the band-head spin, and parity are likely to be extracted. On the other hand, the VMI model calculations are quite simple and are capable of predicting the threshold limits of band-head spin, the quadrupole moment, and the excitation energy, which in turn are significantly useful for deciding an appropriate configuration assignment in the PAC model calculations of the existing as well as upcoming SD bands. Further, the VMI model calculations involve the variation of the moment of inertia with angular momentum, which in turn is quite helpful in understanding the mechanism of the observed identical SD bands between a pair of neighboring nuclei.

An Adaptive Sliding Mode Control for Multi-Span Nonlinear Web Material Linkage Systems

This study presents an adaptive controller for multi-span nonlinear web material linkage systems with the characteristic of a variable moment of inertia and operating radius of rolls. Sliding mode control is used to control web tensions as well as velocities of the system due to its robustness against modeling imprecision. In addition, an adaptive law combined with sliding mode control is proposed to estimate the moment of inertia. As a result, the adaptive sliding mode control structure takes advantage of nonlinear sliding mode control and adaptation algorithm to deal with parameter changes. To verify the controller, the stability of the whole system is proved based on Lyapunov’s stability theory. The simulation results illustrate reliable performance by comparing several nonlinear controllers.

磁気粘性流体を用いた可変慣性モーメント型振動抑制装置（強化学習による慣性接続質量切替時の地震波加振実験）

磁気粘性流体を用いた可変慣性モーメント型振動抑制装置（強化学習による慣性接続質量切替時の地震波加振実験）

Variable Moment of Inertia of Area Type Stiffness Changing Mechanism with Archshaped Thin Flat Spring

Variable Moment of Inertia of Area Type Stiffness Changing Mechanism with Archshaped Thin Flat Spring

On the applicability of Southwell’s method to the determination of the critical force of elastic columns of variable cross sections

Brilliant in its simplicity, Southwell’s method of experimentally determining the critical force on the basis of the so-called Southwell diagram has been of interest to structural stability specialists since its presentation in 1932. In its original version, the correctness of the Southwell method was proved for compressed bars with a constant cross section and showing the loss of stability only within the elastic range while maintaining the constant value of Young's modulus. In numerous works on the method, proposals for its modification have emerged ensuring the extension of the scope of applications with problems other than the classic buckling of a compressed bar. There has also been an attempt to justify the correctness of Southwell’s method in the case of a bar with a variable cross section. This paper presents a strict solution of the differential equation of bar stability with a parabolic variable moment of inertia of the cross section and a parabolic form of initial geometric imperfections. The solution arrived at with the use of the Mathematica™ system was the basis for constructing the Southwell diagram and justifying the correctness of the method for this particular case of a bar. To confirm the correctness of Southwell’s method also the numerical approach exploiting FEM was adopted. Two different cases of column’s shape variabilities and different boundary conditions were considered.

Extended Kalman filter and Takagi-Sugeno fuzzy observer for a strip winding system

This paper proposes two nonlinear estimation approaches, namely based on Extended Kalman Filter (EKF) and a Takagi-Sugeno Fuzzy Observer with 32 rules (TSFO-32), for a Strip Winding System (SWS) characterized by variable reference input, variable moment of inertia with constant increasing tendency and variable parameters. The SWS is a complex and nonlinear mechatronic system viewed as a controlled process, which wraps a strip with constant linear velocity on a reel, and the variable radius modifies both the angular velocity and the moment of inertia. The motivation of using EKF is the zero stationary error at low speeds. The motivation of using TSFO-32 is that once the Takagi-Sugeno fuzzy models are obtained, various analysis and design tools initially developed for linear systems, which facilitate the observation and/or synthesis of the controller for complex nonlinear systems, can be adapted appropriately and used in these nonlinear systems. Therefore, these tools simplify the design as well-established approaches and algorithms are available. The fuzzy control system stability and observer design conditions are derived and expressed as linear matrix inequalities. The efficiency of TSFO-32 is discussed in this paper in terms of setting a certain convergence rate. The performance of the two nonlinear estimation approaches is validated by means of digital simulations conducted for three values of the moment of inertia.

INFLUENCE OF ELASTIC AND INERTIAL PARAMETERS OF THE PULLEY OF VARIABLE MOMENT OF INERTIA ON ITS DYNAMIC CHARACTERISTICS

In order to reduce the dangerous effects of resonant phenomena that occur during the start of the ropeway drive, this paper proposes the use of a pulley of variable moment of inertia. The influence of elastic and inertial parameters of the pulley on the values of eigenfrequencies was investigated using simulation modeling in the Solidworks computer-aided design system with Motion application. As a result, it was found that a decrease in the mass of the load with a proportional increase in stiffness and dissipation coefficient of the spring blocks leads to a decrease in the eigenfrequency of the pulley; reducing the stiffness of the spring blocks under conditions of constant weight of the load causes a significant reduction in the eigenfrequency of the pulley, but requires the use of load limiters; increasing the share of the mass of the load in the total mass of the pulley leads to an expansion of the range of changes in the moment of inertia of the pulley.

Optimization of powered wheels for commercial aircraft and design of test scheme

Electric landing gear drives equipped with traction motors are able to power the wheels of single-aisle commercial aircraft to provide the capability of taxiing on the ground. The powered wheels are utilized to solve the problems of low engine efficiency, high fuel consumption and high pollution of the aircraft during the taxiing process. The powered wheel electric drive system consists of an electric traction motor, a set of planetary gear assembly, and a wheel. This paper optimizes the parameters of the planetary gear assembly of the electric drive system to improve the outputted torque of the powered wheel. After that, two test schemes are designed for the powered wheel electric drive system to measure its torque. These two test schemes use moment of inertia and resistance loading to replace the actual vertical load of the aircraft applied on the powered wheel during the taxiing process. The first scheme uses the mass block to simulate the mass of the general aircraft, whereas the second scheme uses a flywheel with a variable moment of inertia to simulate the mass of large commercial aircraft.