Inertia Of Flywheel Research Articles

Electromagnetic Field and Variable Inertia Analysis of a Dual Mass Flywheel Based on Electromagnetic Control

The moment of inertia of the primary flywheel and the secondary flywheel in a dual mass flywheel (DMF) directly affects the vibration damping performance in an automotive driveline. To enable better minimization of vibration and noise by changing the moment of inertia of the DMF to adjust the frequency characteristics of the automotive driveline, a new variable inertia DMF structure is proposed by introducing electromagnetic devices. The finite element simulation model of the electromagnetic field of an electromagnetic device is established, the electromagnetic field characteristics in the structure are analyzed, and the variation in the electromagnetic force under different air gaps and current conditions is obtained. The electromagnetic force test system of the electromagnetic device is constructed, and the validity of the finite element simulation analysis of the electromagnetic field of the electromagnetic device is verified. A mechanical model of the electromagnetic device is established to analyze the characteristics of the displacement of the moving mass in the structure as well as the variation in the moment of inertia of the DMF at different rotational speeds and currents. The maximum adjustable proportion of its moment of inertia can reach 15.07%. A torsional model of the automotive driveline is established to analyze the effect of variable inertia DMF on the resonance frequency of the system under different currents. The results show that the electromagnetic device introduced in the DMF can realize the active adjustment of the moment of inertia and enable the resonance frequency to decrease with increasing rotational speed, which expands the idea of optimizing the vibration damping performance of the DMF and provides a reference for better control of the torsional vibration of the automobile or other mechanical transmission systems.

Effects of Inertial Flywheel Training vs. Accentuated Eccentric Loading Training on Strength, Power, and Speed in Well-Trained Male College Sprinters.

This study aimed to evaluate and compare the effects of inertial flywheel training and accentuated eccentric loading training on the neuromuscular performance of well-trained male college sprinters. Fourteen sprinters were recruited and randomly assigned to either the flywheel training (FWT, n = 7) group or the accentuated eccentric loading training (AELT, n = 7) group. The FWT group completed four sets of 2 + 7 repetitions of flywheel squats, whereas the AELT group performed four sets of seven repetitions of barbell squats (concentric/eccentric: 80%/120% 1RM). Both groups underwent an eight-week squat training program, with two sessions per week. A two-way repeated ANOVA analysis was used to find differences between the two groups and between the two testing times (pre-test vs. post-test). The results indicated significant improvements in all measured variables for the FWT group: 1RM (5.0%, ES = 1.28), CMJ (13.3%, ES = 5.42), SJ (6.0%, ES = 2.94), EUR (6.5%, ES = 4.42), SLJ (2.9%, ES = 1.77), and 30 m sprint (-3.4%, ES = -2.80); and for the AELT group: 1RM (6.3%, ES = 2.53), CMJ (7.4%, ES = 3.44), SJ (6.4%, ES = 2.21), SLJ (2.2%, ES = 1.20), and 30 m sprint (-3.0%, ES = -1.84), with the exception of EUR (0.9%, ES = 0.63, p = 0.134), showing no significant difference. In addition, no significant interaction effects between group and time were observed for 1RM back squat, SJ, SLJ, and 30 m sprint (p > 0.05). Conversely, a significant interaction effect between group and time was observed for both CMJ and EUR (p < 0.001); post hoc analysis revealed that the improvements in CMJ and EUR were significantly greater in the FWT group compared to the AELT group (p < 0.001). These findings indicate that both FWT and AELT are effective at enhancing lower-body strength, power, and speed in well-trained male college sprinters, with FWT being particularly more effective in promoting elastic energy storage and the full utilization of the stretch-shortening cycle.

Theoretical study of a novel resettable‐inertia damper: Dynamic modeling, equivalent linearization, and performance assessment

AbstractTo passively achieve an inertial device with unidirectional force transmission similar to Bang Bang control, this study introduces a novel energy dissipation device known as the resettable‐inertia damper (RID). The ingenious motion principles of the RID, encompassing a rack‐and‐pinion, bevel gear commutation system, speed transmission, and eddy current damping, are elucidated in detail. In particular, a unidirectional rotational flywheel within the device selectively engages when the primary structure reciprocates. The physical mass of the flywheel undergoes conversion into an amplified inertia through the rack‐and‐pinion mechanism, which enables the enhancement of damping effects coupling the flywheel rotation and eddy current configuration. A coupled multibody dynamic model, combining the clutching effect, the flywheel inertia, and the rotational damping, is formulated to analyze the system with RID (RIDS). Currently, an analysis of the hysteretic behaviors of RID is carried out. To facilitate the design and evaluation of the performance of RIDS, an equivalent linearization method is proposed for RIDS. The feasibility of this simplified method is validated under harmonic excitation. Additionally, the study examines the performance of equivalent linear systems (ELSs) and RIDS under natural ground motions and stochastic stationary excitation in peak and variance responses levels, respectively. Comparison of RID with traditional inerter shows that RID can achieve a more pronounced control with less force transferred to the structure and with the potential to recover vibration energy, highlighting its unique advantages.

Effect of flywheels in pump stations for reducing the volume of air chambers

ABSTRACT The most common and destructive event of unsteady flow in pipes is water hammer. This phenomenon is caused by a sudden change in boundary conditions in pressurized pipes. Unsteady flow in pipelines can lead to a significant increase or decrease in pressure. This pressure generation may cause cavitation, bursting of pipes, and failure of the whole system. One type of equipment that can control both positive and negative pressure phases is a pressurized tank. Implementing such a pressure tank can impose increased costs. In order to reduce the design costs, the combination of a flywheel with the pressure tank can be used. In this study, a transmission pipeline from Zarineh River to Tabriz city is numerically simulated, and the effect of increasing the inertia of the flywheel on the reduction of the pressurized tank volume is investigated. The results show that increasing the flywheel inertia from 125 to 165 Nm2 can reduce the pressurized tank volume from 90 to 75 m3.

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.

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.

Acute effects of eccentric overload training with different loading doses in male sprinters

ObjectiveThe primary objective of this study was to investigate the immediate effects of two doses (Dose1 and Dose2,D1 and D2) of inertial Flywheel Eccentric Overload (FEOL), Eccentric Hook (EH), and High-intensity Half Squat (HHS) on muscle explosiveness in male sprinters. MethodsTwenty-one sub-elite male sprinters were randomly assigned to three groups: the FEOL group (n=7), the EH group (n=7), and the HSS group (n=7),Measurements of athletes' explosive jumps (CMJ, SJ, SLJ) heights, relative peak power indices, and 30-m sprint times were collected before and 6 min after the intervention. ResultsAt D1 loading dose, CMJ, SJ jump height, and relative peak power increased significantly (p < 0.05) after HHS training intervention, while there was no significant change in FEOL and EH training (p > 0.05). At D2 loading dose, CMJ, SJ jump height, and relative peak power increased significantly (p < 0.01) after FEOL and EH training intervention, but at D2HHS intervention, these indexes tended to decrease (p < 0.05). None of the three training protocols significantly improved SLJ performance (p > 0.05). CMJ vertical jump height and relative peak power were significantly higher after D2FEOL and D2EH interventions than after D1HHS (P < 0.05). ConclusionD1HHS, D2FEOL and D2EH3 intervention methods can all improve the performance of sub-elite athletes in the 30-m test, CMJ test and SJ test. in the CMJ test, FEOL training demonstrated a higher acute augmentation effect compared to EH training.

Impact of Engine Inertia on P2 Mild HEV Fuel Consumption

The energy management system (EMS) of a hybrid electric vehicle (HEV) is an algorithm that determines the power split between the electrical and thermal paths. It defines the operating state of the power sources, i.e., the electric motor (EM) and the internal combustion engine (ICE). It is therefore one of the main factors that can significantly influence the fuel consumption and performance of hybrid vehicles. In the transmission path, the power generated by the ICE is in part employed to accelerate the rotating components of the powertrain, such as the crankshaft, flywheel, gears, and shafts. The main inertial components are the crankshaft and the flywheel. This additional power is significant during high-intensity acceleration. Therefore, the actual engine operation is different from that required by the power split unit. This study focuses on exploring the influence of engine inertia on HEV fuel consumption by developing a controller based on an equivalent consumption minimisation strategy (ECMS) that considers crankshaft and flywheel inertia. The optimal solution obtained by the ECMS controller is refined by incorporating the inertia effect of the main rotating components of the engine into the cost function. This reduces the engine operation during high inertial torque transient phases, resulting in a decrease in vehicle CO2 emissions by 2.34, 2.22, and 1.13 g/km for the UDDS, US06, and WLTC driving cycles, respectively.

Dose-Response Effect of an Inertia Flywheel Postactivation Performance Enhancement Protocol on Countermovement Jump Performance.

The purpose of this study was to investigate the dose-response effect of a high-load, 6-repetition, maximum effort inertial flywheel (IFw) squat postactivation performance enhancement (PAPE) protocol on countermovement jump (CMJ) performance metrics. Thirteen subjects completed 5 squat testing sessions: 1 session to determine back-squat 6-repetition maximum, 1 session to determine 6-repetition maximum IFw load, and 3 sessions to investigate the dose-response effect of an IFw PAPE protocol set at the load determined in the second session. In the IFw PAPE sessions, subjects completed either 1, 2, or 3 sets of IFw squats, then performed 5 CMJs over 12minutes (1, 3, 6, 9, and 12min post-IFw). All CMJ tests were conducted on a force platform where CMJ performance outcomes and impulse variables were calculated. There was no main time or volume effect for jump height, contact time, reactive strength index, peak force, or any of the impulse variables. A main time effect was identified for flight time (P = .006, effect size = 0.24) and peak power (P = .001, effect size = 0.28). The lack of change in jump height may indicate that too much fatigue was generated following this near-maximal IFw squat protocol, thereby reducing the PAPE effect.

Research on Nonlinear Vibration of Dual Mass Flywheel Considering Piecewise Linear Stiffness and Damping

Nonlinear torsional vibration differential equation of the nested arc-shaped short spring dual mass flywheel (DMF) is established, considering the piecewise linear stiffness and damping of the spring. The first-order approximate analytical solution under sinusoidal excitation and the amplitude–frequency characteristic function are obtained by means of the average method which verified by the Runge–Kutta (R–K) method. The effects of the parameters of input excitation, inertia, and piecewise linear stiffness and damping of DMF on the resonant amplitude, resonant frequency band, and equivalent linear natural frequency of the system are analyzed. The results show that the amplitude–frequency characteristic curve bending and jumping with the changes of excitation frequency and the peak of resonant amplitude can be obviously reduced by increasing the inertia of the primary flywheel and decreasing the inertia of the secondary flywheel. The complex nonlinear dynamic phenomena such as Period 1, quasi-periodic, and chaos are obtained by analyzing the forced vibration response under the different excitation frequencies.

Co-design of a wave energy converter for autonomous power

A “bolt-on” wave energy converter is designed to provide power for sensors on an existing oceanographic buoy. The narrow-banded pitch/roll response of the target oceanographic buoy lends itself to a tuned-resonator design, for which we suggest a novel “pitch resonator” wave energy converter concept. Using a pseudo-spectral method, the performance of the proposed wave energy converter is modeled in the range of sea states expected to be present at the target deployment location to study the effect of flywheel inertia on performance. The results show that the system can marginally meet the desired power demands, but suggest that related design concepts may be worth consideration.

Dynamic performance of structures with clutching inertia‐damping system: Theoretical study

AbstractThis paper addresses performance limitations in passive clutching inertia devices due to the absence of flywheel deceleration damping. A solution introducing viscous damping to serve as the flywheel deceleration mechanism is proposed, thus forming the “CIDS” (Clutching Inertia‐Damping System). The study establishes a multi‐body motion analysis model for the CIDS within a single‐degree‐of‐freedom structure. Simulations investigate the impact of control force model parameters on the computation. The impact of additional damping on structural dynamic responses and the system's relative motion is thoroughly elucidated and revealed through dynamic simulations and multi‐body motion decomposition. The “ELS” (Equivalent Linear System) is introduced for the simplified performance assessment of CIDS. Expressions for equivalent damping and inertance are derived based on the equivalence of vibration period and energy in sinusoidal steady‐state vibration. The feasibility and accuracy of ELS for assessing CIDS's performance are validated through response analyses under harmonic and seismic excitations. Notably, displacement indicators exhibit higher precision than acceleration. When subjected to seismic excitation, selecting a more suitable excitation frequency to determine the corresponding equivalent damping can enhance the accuracy of ELS. Considering the frequency dependence of equivalent damping, a frequency‐domain‐based random response evaluation method is proposed. The influence of additional rotational damping, flywheel inertia, and structural natural period on random response is evaluated and analyzed. In CIDS with similar rotational damping and inertia, its control effect is related to the excitation. In summary, this study offers a structured framework for comprehending and evaluating the performance of CIDS, offering valuable insights into its potential engineering design, applications, and analysis.

Performance Analysis of a Designed Prototype of a Motor Coupled Variable Inertia Flywheel System

The presence of a substantial moment of inertia in a flywheel poses challenges at the initiation of rotation in a rotating machine. During stable operation at high velocities, several energy-saving advantages can be efficiently attained, allowing for the potential of achieving adequate energy savings in specific applications. One potential solution to address this issue is the implementation of a flywheel that possesses the ability to modify its moment of inertia. While it is possible to derive the concept of variable inertia by adjusting the radii of the masses in relation to the axis of the flywheel, the techniques employed to regulate the variable inertial flywheel are rather intricate. This study presents an implementation of a variable inertia flywheel system coupling with electrical machinery to reduce power consumption. The main objective of the study is to reduce energy consumption utilizing variable inertia flywheel. Under various motion scenarios, the advanced machine’s dynamic reaction is examined. Finally, a standard testing method demonstrates almost ninety seven percent similarity between an analytical and practical analysis.

Design, Dynamics Modeling, and Experiments of a Vibration Energy Harvester on Bicycle

Harvesting vibration energy during riding for powering on-board appliances has been demanded. However, few vibration energy harvesters on bicycle have been reported and the output power can hardly satisfy the requirement. A vibration energy harvester for bicycle is proposed based on a directional variable inertia flywheel and coaxial mechanical motion rectifier, in order to improve the output power and stability via improving the ratio of inertia and damping. The coaxial mechanical motion rectifier is designed to convert reciprocating rotation to unidirectional rotation, and the directional variable inertia flywheel is designed to extend the overrunning phase. Dynamic modeling with two-degree-of-freedom is proposed with the consideration of the nonlinear velocity response in the overrunning phase. The input force and output voltage are simulated with different input signals and external resistances. Lab tests demonstrate that the directional variable inertia flywheel is beneficial to increasing the output power, and maximum output power of 1.73 W is achieved. Finally, road tests of applying the vibration energy harvester on a bicycle are carried out, and average output power of 2.11 W and maximum power of 9.77 W are achieved.

Investigation into the Optimal Number of Repetitions Needed to Maintain Power Output in the Flywheel Romanian Deadlift Exercise

The aim of this study was to investigate the desired number of repetitions required to maintain a consistent maximum power output of concentric, eccentric, and eccentric overload in a flywheel Romanian deadlift (FW RDL). Fourteen male recreational athletes (27.9 ± 6.4 years old, 90 ± 10.7 kg, 180.7 ± 5.5 cm tall) participated in the study. They had a minimum of two years resistance training experience, but none of them had any experience in flywheel inertia training (FIT). The participants performed FW RDL on an FW device (kBox 3, Exxentric, ABTM, Bromma, Sweden). Each participant attended a single test session. The testing session consisted of four sets of 14 repetitions of the RDL. Both the first and second repetitions of each set were used to ‘increase momentum’ and were excluded from data analysis. Each set incorporated different inertial loads. The order of inertial load settings was randomised for each participant. A five-minute inter-set rest period was given to allow the cessation of any fatigue effects and to enable adequate recovery. During the repetition analysis, a ≥ 20% drop in value from the preceding repetition was used as a cut-off point and recorded. The optimal number of repetitions required to maintain peak concentric and eccentric power was between 10 and 11, whereas 6 to 8 repetitions is advised to maintain eccentric overload.

The Relationship between Bodyweight, Maximum and Relative Strength, and Power Variables during Flywheel Inertial Training

The main aim of this study was to examine the relationship between body weight, absolute and relative strength and power variables in a flywheel Romanian deadlift. A secondary aim was to assess the inter-day reliability of a novel power assessment protocol previously used to determine the inertial load that produced the maximum power output in Flywheel Inertia Training. Ten physically active males took part in this study. Participants had some experience with flywheel devices, but all had a minimum of 24 months of traditional resistance training experience. The first testing session consisted of three sets of 10 repetitions with a different inertial load for each set (0.050, 0.075, and 1.00 kg·m2). Each set’s first and second repetitions were used to build momentum and were excluded from data analysis. The order of inertial load used in each trial was standardized for all participants: first, 0.050 kg·m2, second, 0.075 kg·m2, and last, 0.100 kg·m2. The secondary testing session followed the same procedure as the first. No statistically significant (p &lt; 0.05) effect was found between any of the variables in the correlation analysis. There were large positive correlations between the 1 repetition max flywheel Romanian deadlift and peak concentric power, relative strength, and peak concentric and eccentric peak powers. Both body weight and relative strength showed moderate negative correlations with % eccentric overload, whereas moderate positive correlations were observed between 1RM and peak eccentric power. Both concentric power and eccentric power showed excellent reliability, while the reliability for % eccentric overload ranged from poor to excellent depending on the inertial load. In conclusion, this study shows that a protocol to assess the maximum power output has excellent reliability for both ECC and CON power and may be used in future flywheel training. The results also showed that body weight, maximum strength, and relative strength were not largely related to power variables. An individualized approach to flywheel training is required.

Simulation of a loss of flow transient of a small Lead-Cooled reactor using a CFD-Based model

The recent development of small modular reactors needs to be followed by safety analysis using the newest available tools. This work focuses on one type of reactor, SEALER, which is a small lead cooled reactor intended for remote communities in Canada. Simulations of a loss of flow transients are performed using a CFD-based model that was specifically developed for this project. The CFD geometry includes the entire primary circuit with some simplifications. The fuel channel, steam generator and pumps use a simple geometry with momentum source and heat source/sink. Free surface level is modelled with the multiphase volume of fluid (VOF) method. The CFD part of the model is coupled to a custom code for heat transfer in the fuel rods and point kinetics for neutronics. Transient results show that core temperatures do not increase significantly and stay well below coolant boiling and fuel melting points. The CFD-based model presented here is compared against a lumped-parameter model using the same transient. It is shown that the evolution of the mass flow and temperature is significantly different and more detailed with the CFD-based model. Finally, the influence of the moment of inertia of the pump flywheel on the transient is explored.

Effect of Fabricated Twin Roller Arrangement of Chassis Dynamometer on Measurement of Performance Parameters of Electric Two Wheelers

The majority of vehicle dynamometer test rigs available in the market are constructed rigidly, which can test vehicles with a very narrow range of specifications, so there is a need for provision for load compensation to simulate the vehicle in order to test different vehicles &amp; enhance the quality of measured results. The fabricated twin roller arrangement improves tire-roller contact and the provision for balancing system inertia with the inertia of the vehicle improves the accuracy of results during testing &amp; makes the chassis dynamometer system a versatile test rig to test different vehicles and test parameters like speed, acceleration, brake force and brake distance, etc. A light weight and low base inertia fabricated twin roller arrangement is designed in the present study, and an inertia flywheel arrangement is connected to it for load compensation during acceleration, and an experiment is performed by loading an electric two-wheeler onto a two-roller setup to evaluate its performance. After testing an electric vehicle, the maximum speed and acceleration were determined to be 95 km/h and 3.65 m/s², respectively, and the brake force was 279.8 N with a braking distance of 7.48 m when applied from a speed of 20 km/h to zero. The obtained results were precise due to vehicle stability, provision for load compensation for vehicle simulation, and use of a mechanical inertia simulation using a flywheel in this test rig, which can be used to test different vehicles with a wide range of test specifications.

Mechanically-driven energy harvester in railway freight system: Integrated modeling and performance analysis

Vibration energy harvesters (VEHs) convert mechanical energy of unpowered freight wagons into electricity and unlock more smart devices to improve operating conditions. In this paper, the nut-screw-based mechanically-driven VEHs (MD-VEHs) along with several mechanical motion rectifiers (MMRs) are proposed and compared in nonlinear railway freight system. Firstly, the working principles of harvesters with non-MMR, half-wave and full-wave MMRs are researched, and equivalent circuit models are established to better reveal the engagement and disengagement of one-way clutches, followed by the integrated model of wagon-harvester system which studies the suspension vibration response and assesses harvester performance. The harvester equivalent circuit model is validated on a horizontal test bench, and presents a good consistency with test data. In addition, the effects of harvester equivalent damping and inertia on performance are explored systematically. The analysis results indicate that full-wave MMR presents the best power performance under the same parameter configuration. The increase of flywheel inertia will decrease the power generation capacity of non-MMR configuration, but further enhance those of half-wave and full-wave MMRs and narrow the performance gap between both. This analysis based on system coupling will be instructive for the engineering design and application of railway VEHs.

An electromagnetic energy harvester for applications in a high-speed rail pavement system

Energy harvesting from ambient environment is one of the effective solutions to supply power for low power electronic devices. There are still some challenges such as poor space utilization and low power density for pavement energy harvesters. In this paper, an electromagnetic energy harvester with the double rockers is proposed to harvest the human footstep energy from high-speed rail pavement environment. Combined with two one-way bearings, the proposed double-rocker structure converts up and down motion of plate into a unidirectional rotation motion of the shaft. As the effect of the inertia flywheel, the velocity attenuation of the shaft of generator is slowed down. The dynamic model of the energy harvester with the engagement and disengagement phase is explored. Moreover, the input force and the angular velocity are simulated under the input of the various sinusoidal displacements and frequencies. The simulation and experimental results show that it can obtain the maximum output power of 466.6 mW under the vibration frequency of 5 Hz and the displacement of 10 mm. Further, the inertia flywheel can enhance the system stability and achieve the improvement of average output power by 49.45 % compared with no flywheel system. A pavement block with four energy harvesters is assembled and the actual field test proves it can obtain the maximum voltage of 54.4 V and the output power of 1.034 W, which proves the proposed electromagnetic energy harvester has great potential to achieve self-powered monitoring system and power for the low power electronic devices in high-speed rail environment.