Browse Topic: Flywheels

Items (405)
ABSTRACT The next generation of military vehicles will require new and improved power systems. As fuel prices continue to rise and as power draws become greater on tactical wheeled vehicles, the performance and efficiency of the power system becomes more important. Up to 40% of vehicular traffic in combat theater is dedicated to fuel and water logistics. Reduction in fuel consumption will result in less traffic and reduced exposure to IED’s as well as gains in cost efficiency. Advances in powertrain and vehicle systems are required to achieve these gains. Hybrid propulsion systems have been proven in passenger automobiles as well as some commercial applications. This technology enables fuel economy improvements upwards of 25%. Hybrid systems can also provide export power and silent watch capability for military vehicles. Duty cycle and environmental demands are more severe in military applications and current energy storage devices are not robust. Several hybrid military platforms have
Milner, DavidSmith, WilfordAlbers, Ken
In crank- train system, the prime objective of crankshaft is to facilitate the transformation of reciprocating motion of connecting rod into rotational motion at flywheel end. Moreover, the contribution of mass from crankshaft is in the same order as of flywheel assembly mass which accounts to approximately 40% to 50% of total mass of engine. Therefore, to accomplish the development of an efficient engine it is vital to optimize the crankshaft based on simulation parameters like balance rate, mass, torsional frequency, web shear stress etc. In the given work, crankshaft has been designed and developed for an engine used in light duty commercial vehicle. The defined work demonstrates the application of 1D simulation tool AVL Excite in development phase of the engine. To establish equilibrium between the weight and simulation guidelines, many iterations of models were evaluated and finally we were able to achieve mass reduction of nearly 8% from the base model. Thenceforth, validation of
Khandelwal, MehaKaundabalaraman, KaarthicRathi, Hemantkumar
This research paper focuses on the modelling and analysis of a flywheel energy storage system (FESS) specifically designed for electric vehicles (EVs) with a particular emphasis on the flywheel rotor system associated with active magnetic bearings. The methodology used simulation approaches to investigate the dynamics of the flywheel system. The objective of this study is to explore the effects of implementing the flywheel energy storage system on the performance of the EV. The paper presents a comprehensive model of the flywheel energy storage system, considering the mechanical and electrical aspects. The mechanical model accounts for the dynamic behaviors of the flywheel, including parameters such as rotational speed, inertia, and friction. The electrical model describes the interaction between the flywheel and the power electronics, such as the converter and motor/generator. To evaluate the benefits of the flywheel energy storage system, simulations are conducted. Simulation studies
Akhtar, Juned
Estimated engine torque is an important parameter used by automotive systems for automated transmission and clutch control. Heavy-duty engine and transmission manufacturers widely use SAE J -1939 based ECU torque calculation based on mass air/fuel flow steady state maps created during calibration of the engine for this purpose. As an alternative, to enhance the accuracy of this important control variable, a virtual flywheel torque sensor (VFTS) was developed. It measures the engine torque based on the harmonics of the instantaneous flywheel speed signal. Initial dynamometer testing showed the VFTS estimated torque values exhibited a maximum inaccuracy of 12% of the actual measured torque over the range of conditions tested. In this paper we report the results of on road truck testing of the VFTS. A loaded heavy truck with a gross vehicle weight rating of 80,000 pounds was used. The performance of the VFTS was tested in different gears at full throttle in the diesel engine speed range
Iddum, VivekBair, JohnChahal, Iqbal SinghMason, PaulGhantasala, Muralidhar K.
This paper describes a simulation methodology developed for gear rattle severity evaluation and drivetrain architecture optimization. The noise generated by gear rattle is one of the main contributors towards customer’s overall NVH perception. This study adopts a model-based design approach to simulate the tendency of gear rattle in neutral and drive conditions. Gear rattle simulation model for Tractor driveline developed in 1-D environment and correlated with test data acquired on tractor drivelines for multiple field applications. This analytical physics-based model includes engine torsional signature, clutch damper torsional characteristic and dynamics of traction and PTO driveline. This dynamic simulation model helps to understand and predict the gear rattle severity of various drivetrain architecture early in the product development cycle and assess & Optimize driveline NVH performance. The simulation model predicts the mesh force variation between the gear pairs based on engine
Kumar, SuneelVeerkar, VikrantMemane, Nilesh
Although electricity is necessary for a country's economic development, many countries lack suitable grid infrastructure. Portable generators offer a consistent electric supply in the event of a blackout. Be-Rex B.V. develops and already assembled a revolutionary engine-generator prototype. It eliminates the use of camshafts, crankshafts and flywheels while integrating the generator parts into the same spherical housing. Thus, it constitutes a compact, lightweight and cost-efficient singular unit. There is no mechanical power output while the load of the engine is determined by the demanded load of the generator. The four combustion chambers are arranged in pairs on the north and south hemisphere and the magnets of the stator are placed circumferential at the equator of the spherical housing. The rotating disc and the joiner build the rotor of the generator. While developing the engine special emphasis has been put on its multi-fuel capability. Optimized gas exchange together with an
Bekking, PimPuts, GodfriedSpiller, MartinBikas, Georgios
In this work, the progressive disassembly method is used to determine the mechanical losses contributed by the different components of a single-cylinder spark ignition engine tested at crankshaft angular speeds of 300−1900 min-1, and lubricant temperatures between 30−35 °C. From the experimental measurements, the losses due to the intake and exhaust manifolds, cylinder head, valve train, camshaft bearings, connecting rod-piston assembly, flywheel, and crankshaft bearings are determined. It is obtained that the elements with the highest contribution are the piston-connecting rod assembly and the cylinder head with contributions of 19.2−36.9% and 27−33.3%, respectively. Additionally, the indicated diagram method is applied to assess the pumping, heat, and blow-by losses of the complete motored engine during the intake and exhaust processes. Pumping losses, heat and blow-by transfers, friction, and auxiliary losses are characterized, obtaining contributions between 5.8−14.7%, 14.8−37.9
Romero, Carlos AlbertoRamírez, Juan DavidHenao Castañeda, Edison de Jesús
This SAE Standard was developed to provide a method for indicating the direction of engine rotation and numbering of engine cylinders. The document is intended for use in designing new engines to eliminate the differences which presently exist in industry
Engine Power Test Code Committee
Suppose we have two identical variable-inertia flywheels and we connect them to the inputs of a differential. The output is connected to the driveline of a vehicle. There are several types of three-element mechanical differentials (e.g. ring-gear/carrier, epicyclic, etc.). The specific type of 3-element mechanical differential is inconsequential in the following analysis except to say there are two inputs (e.g. side gears) and one output (e.g. carrier/ring-gear). What’s important is simply the relationship - For example, using the notation ‘a’ for the first side gear and ‘b’ for the second side gear and ‘c’ for the carrier, then the relationship is: c=(a+b)/2. Understand that ‘a’, ‘b’, and ‘c’ can each be an input or an output. Using the designation ‘omega’ (ω) then the relationship looks like this: ωc=(ωa+ωb)/2. So, we have one variable inertia flywheel (VIFa) and a second variable inertia flywheel (VIFb) connected to two side gears, a and b, and a vehicle driveline connected to the
Gramling, James
Automotive companies are constantly looking to increase the fuel efficiency, shift quality, passenger comfort, and to reduce wear and tear on the components. Most of these aspects depend on the accuracy of torque used for transmission control, which determines the required operational gear position at a given speed and road conditions. Currently, SAE J-1939 CAN bus torque estimation relies on steady state maps that are generated during the calibration of the engine for different speeds and loads. In this paper we report the development of a Virtual Flywheel Torque Sensor (VFTS) useful for real time torque measurement based on an engine speed harmonics analysis. The VFTS uses a signal from the flywheel speed sensor to estimate the flywheel angular acceleration, which and provides a proportional torque value which corresponds to torque at the flywheel. The performance of the VFTS is evaluated using an engine with flywheel attached to driving a dynamometer at different torque loads (100
Iddum, VivekChahal, Iqbal SinghBair, JohnGhantasala, Muralidhar K.
Dual mass flywheel (DMF) is an excellent solution to improve the noise, vibration, and harshness (NVH) characteristic of any vehicle by isolating the driveline from the engine torsional vibrations. For the same reason, DMF’s are widely used in high power-density diesel and gasoline engines. However, the real-world usage conditions pose a lot of challenges to the robustness of the DMF. In the present work, by capturing the Real-World Usage Profile (RWUP) conditions, a new methodology is developed to evaluate the robustness of a DMF fitted in a Sports utility vehicle (SUV). Ventilation holes are provided on clutch housing to improve convective heat transfer. Improvement in convective heat transfer will increase the life and will reduce clutch burning concerns. Cities like Mumbai, Chennai, Bangalore, roads will have clogged waters during rainy season. When the vehicle was driven in such roads, water enters inside the clutch housing through ventilation holes. Prolonged usage of vehicle in
S, KesavprasadM, SudhanVijayarangan, DeepakRai, Vikas
The goal of reducing fuel consumption and CO2-Emission is leading to turbo-charged combustion engines that deliver high torque at low speeds (down speeding). To meet NVH requirements damper technologies such as DMF (Dual Mass Flywheel) are established, leading to reduced space for the clutch system. Specific measures need to be considered if switching over from SMF (Single Mass Flywheel) to DMF [8]. Doing so has an impact on thermal behavior of the clutch system, for example due to reduced and different distribution of thermal masses and heat transfer to the surroundings. Taking these trends into account, clutch systems within vehicle powertrains are facing challenges to meet requirements e.g. clutch life, cost targets and space limitation. The clutch development process must also ensure delivery of a clutch system that meets requirements taking boundary conditions such as load cycles and driver behavior into account. Relevant load cycles are derived based on feedback and analysis of
Kapse, Ravi RameshLakshminarayanan, SaravananNémeth, ÁkosThakare, AnkitBernhardt, Johannes
This paper investigates the FPGA resources for the implementation of in-cycle closed-loop combustion control algorithms. Closed-loop combustion control obtains feedback from fast in-cylinder pressure measurements for accurate and reliable information about the combustion progress, synchronized with the flywheel encoder. In-cycle combustion control requires accurate and fast computations for their real-time execution. A compromise between accuracy and computation complexity must be selected for an effective combustion control. The requirements on the signal processing (evaluation rate and digital resolution) are investigated. A common practice for the combustion supervision is to monitor the heat release rate. For its calculation, different methods for the computation of the cylinder volume and heat capacity ratio are compared. Combustion feedback requires of virtual sensors for the misfire detection, burnt fuel mass and pressure prediction. Different alternatives proposed in the
Jorques Moreno, CarlosStenlaas, OlaTunestal, Per
Internal combustion (IC) engines incorporating the conventional slider-crank mechanism are subjected to high frictional power losses mainly due to the piston-rod assembly. Due to its simplicity, IC engines have utilized this mechanism almost unchanged since its introduction. This study introduces the hypocycloid gear mechanism (HGM) as an alternative to the conventional slider-crank mechanism for IC engine systems. The HGM provides several advantages that allow for enhancing both the thermal and mechanical efficiencies of IC engines. In this study, the kinematic and dynamic performances of the HGM engine are analyzed in detail. The geometric relations of the HGM are used to derive the kinematic equations that describe the piston motion. These equations are then used to derive the dynamics equations considering gas and inertia forces acting on the HGM. This study also investigates the effect of attaching a flywheel to the HGM engine and suggests a mass-balancing approach for the engine
ElBahloul, Mostafa A.Aziz, ELsayed S.Chassapis, Constantin
Ensuring continuous electrical power within mission-critical facilities is top of mind for today’s facility managers, data center operators, hospital IT managers, and electrical engineers. Thoughtful planning, design, equipment selection, and maintenance of an organization’s power infrastructure is vital for continuous operations. According to U.S. Energy Information Administration findings, typical utility customers experienced nearly six hours of power interruptions in 2018 in the U.S., largely a result of severe weather or devastating wildfires. With businesses losing upwards of $150 million as a result of blackouts (according to the U.S. Department of Energy), protecting against power outages and disturbances is essential. Equally important is incorporating environmentally friendly power solutions to advance organizations’ green initiatives
In electric vehicles, there is a continuous shift in the charging and discharging of the battery due to energy generation and regeneration. This adds up to the total number of charging-discharging cycles of the battery. This fluctuation amounts to faster battery degradation and life-cycle reduction. Also, we are exploring solutions to improve the low regeneration efficiency of EVs. For example, overall regeneration efficiency from wheels-to-wheels is only around 64% in Tesla Roadster. Even in current EV powertrains, the regeneration efficiency only reaches up to around 75%, which is much lower compared to the potential efficiency of flywheel-based energy storage (FES) as no energy conversion takes place from one form to another. We implemented FESS in a parallel hybrid setup solely for regenerative braking. Based on the power requirements from the vehicle, the drivetrain smartly switches its power source between the Electric motor and flywheel during the drive cycle. It uses a high
Seshadri Venkatesh, PawanChandran, VishnuAnil, Sreeram
The development of energy storage systems has gained increasing interest in recent years, as global energy policies and protocols demand to regulate and use available energy efficiently. Inertia flywheels constitute a simple means of energy storage, which has been integrated into different mechanical systems such as die-cutting machines, internal combustion engines, modern systems such as regenerative braking in automobiles, uninterruptible power systems, etc. In this research work, the design process of a flywheel-based experimental test bench to be used as an up-to 130 kilojouls energy storage capacity, and also to test small capacity internal combustion engines, and to diagnose the performance of engine starters. Setting the requirements and main specifications, the paper presents the followed design process, including the solid modeling, the calculations for the dimensioning of the final concept and prototype. Some experimental performance plots obtained during the preliminary
Romero Piedrahita, Carlos AlbertoRodríguez, Andrés Felipe
This SAE Standard specifies the major dimensions and tolerances for Engine Flywheel Housings and the Mating Transmission Housing Flanges. It also locates the crankshaft flange face or the transmission pilot bore (or pilot bearing bore) stop face in relation to housing SAE flange face. This document is not intended to cover the design of the flywheel housing face mating with the engine crankcase rear face or the design of housing walls and ribs. Housing strength analysis and the selection of housing materials are also excluded. This document applies to any internal combustion engine which can utilize SAE No. 6 through SAE No. 00 size flywheel housing for mounting a transmission
Automatic Transmission and Transaxle Committee
Vehicles with manual transmission are still the most preferred choice in emerging markets like India due to their benefits in cost, simplicity and fuel economy. However, the ever-increasing vehicle population and traffic congestion demand a smooth clutch operation and a comfortable launch behaviour of any manual transmission vehicle. In the present work, the launch performance of a sports-utility vehicle (SUV) equipped with dual mass flywheel (DMF) and self-adjusting technology (SAT) clutch could be improved significantly by optimizing the clutch system. The vehicle was observed to be having a mild judder during clutch release (with 0% accelerator pedal input) in a normal 1st gear launch in flat road conditions. An extensive experimental measurement at the vehicle level could reveal the launch judder is mainly due to the 1st order excitation forces created by the geometrical inaccuracy of the internal parts of the clutch system. Moreover, the forces are amplified by the resonance of
Vellandi, VikramanSomarajan, Suresh KumarNagarajan, JaganathanVIJAYAN, Arunkumarkarbade, RohanRamanathan, Muthuraman
Dual mass flywheel (DMF) is an excellent solution to improve the noise, vibration and harshness (NVH) characteristic of any vehicle by isolating the driveline from the engine torsional vibrations. For the same reason, DMFs are widely used in high power-density diesel and gasoline engines. However, the real-world usage conditions pose a lot of challenges to the structural robustness of the DMF. In the present work, a new methodology is developed to evaluate the robustness of a DMF fitted in a compact sports utility vehicle (SUV) with rear-wheel drive architecture. The abuse conditions (mis-gear, sudden braking, etc) in the real-world usage could lead to a sudden engine stall leading to an abnormally high angular deceleration of the driveline components. The higher rate of deceleration coupled with the higher rotational moment of inertia of the systems might end up in introducing a significantly high impact torque on the DMF. Hence, prolonged usage of the vehicle in abuse conditions
Vellandi, VikramanAP, BaaheedharanVijayarangan, Deepak
Gear rattle is due to impact noise of unloaded gears in transmission having freedom to move in backlash region. Engine order vibrations in the presence of backlash in meshing pairs induce the problem. It is a system behavior wherein flywheel torsional vibrations, the pre-damper characteristics and transmission drag torque plays a vital role in an engine idle condition (hot & cold). Idle rattle is a severe issue, which is highly noticeable in cold condition or after 1st engine crank. Gear rattling observed in idle condition is idle gear rattle or neutral gear rattle, specifically in cold condition is a “Cold idle rattle” and this is one of the critical noise parameters considered for entire vehicle NVH. Damper mechanism in the clutch, is used to serve better isolation (by reducing the input excitation to transmission parts) of vibrations between engine and transmission their by reducing gear rattle intensity. Engine firing order, engine downsizing, down speeding (means high peak torque
Kapse, Ravi RameshMore, VivekGangane, Swapnil
Automotive clutches are rotary components which transmits the torque from the engine to the transmission. During the engagement, due to the difference in speed of the shafts the friction lining initially slips until it makes a complete engagement. Enormous amount of heat is generated due to the slippage of the friction lining, leading to poor shift quality and clutch failure. Depending on the road & traffic conditions, and frequency of engagement and disengagement of the clutch, it generates transient heating and cooling cycles. Hill fade test with maximum GVW conditions being the worst case scenario for the clutch. A test was conducted to understand the performance of the clutch, in which clutch burning was observed. The clutch lining got blackened and burning smell was perceived. The friction coefficient drops sharply to a point until it cannot transmit the torque required to encounter the slope. This further worsen clutch slippage and lead to more severe temperature rise. The major
Santra, Tanmay SushantGopinathan, NagarajanRaju, KumarSugumar, GaneshParadarami, UdayaVellandi, Vikraman
The present work is focussed on the real-world challenges of a dual mass flywheel (DMF) equipped vehicle in the Indian market. DMFs are widely used to isolate the drivetrain from the high torsional vibrations induced by the engine. While DMFs can significantly improve noise, vibration and harshness (NVH) characteristics of a vehicle, there are multiple challenges experienced in real-world operating conditions when compared with the single mass flywheel (SMF). The present work explains the challenges of using a DMF in a high power-density diesel powertrain for a multi-purpose vehicle (MPV) application in the Indian market. Measurements on the flat-road operating conditions revealed that the DMF vehicle is very sensitive for launch behaviour and requires a higher clutch modulation. Vibration measurements at the driver’s seat confirm that the SMF vehicle could be launched more comfortably at the engine idle speed of 850 RPM. However, the DMF vehicle needs a "launch assist" of an
Vellandi, VikramanSomarajan, Suresh KumarGanesh, Mohan Selvakumar
During some critical maneuvers, transmission systems using Dual Mass Flywheel (DMF) may experience overtorques, which could lead to structural damages of the transmission components. In a dual mass flywheel, total inertia is divided into two parts: a primary mass connected to the engine and a secondary mass to the transmission. The torque delivered by the engine is transferred from one mass to the other through a drive plate and a set of arc springs, the latter absorbing the torsional oscillations coming from internal combustion engine and the shocks caused by fast clutch engagements. This paper investigates overtorque issues and proposes a solution based on a torque limiter, consisting of a friction clutch inserted between the two masses, that limits the maximum torque transmitted through it. The basic idea is to replace the classic flat drive plate with a tapered drive plate that functions as a Belleville spring. The experimental analysis carried out on dedicated benches has tested
Galvagno, EnricoVigliani, AlessandroCalenda, Giuseppe
Combustion closed-loop control is now being studied intensively for engineering applications to improve fuel economy. Currently, combustion closed-loop feedback control is usually based on the cylinder pressure signal, which is the most direct and exact signal that reflects engine working process. Although there were some relatively cheap types of in-cylinder pressure sensors, cylinder pressure sensors have not been widely applied because of their high price now. Moreover, the combustion analysis based on cylinder pressure imposes high requirements on the information acquisition capability of the current ECU, such as high acquisition and analog-digital conversion frequency and so on. For developing a low price and feasible technology, a new engine information feedback method based on model calculation and crank angular velocity measurement was proposed. A simplified combustion model was operated in ECU for the real-time calculation of cylinder pressure and combustion parameters. At the
Shi, lichunChen, Tao
The control and design optimization of a Free Piston Engine Generator (FPEG) has been found to be difficult as each independent variable changes the piston dynamics with respect to time. These dynamics, in turn, alter the generator and engine response to other governing variables. As a result, the FPEG system requires an energy balance control algorithm such that the cumulative energy delivered by the engine is equal to the cumulative energy taken by the generator for stable operation. The main objective of this control algorithm is to match the power generated by the engine to the power demanded by the generator. In a conventional crankshaft engine, this energy balance control is similar to the use of a governor and a flywheel to control the rotational speed. In general, if the generator consumes more energy in a cycle than the engine provides, the system moves towards a stall. If the generator consumes less energy, then the effective stroke, compression ratio and maximum translator
Bade, MeharClark, NigelFamouri, ParvizGuggilapu, PriyaankaDevi
The new Stage 5 European regulation for Non Road Mobile Machinery has lowered the limits on pollutant emissions for all the categories of internal combustion engines. An interesting alternative to the implementation of sophisticated after-treatment systems is to downsize the engine, and provide the extra power for peak demands with an electric motor, installed in place of the flywheel. The paper explores the potential of this concept, applied to an industrial engine, manufactured by Kohler, and delivering a maximum power of 56 kW@2600 rpm. The study is supported by a comprehensive experimental characterization of the internal combustion engine and of the electric components. A representative duty cycle is also defined, on the basis of a set of measures, taken in real operating conditions. The analysis of this reference cycle is performed by using a GT-Suite model, comparing different power split strategies. It is found that the ICE total displacement can be reduced from 2.5 to 1.9 L
Mattarelli, EnricoRinaldini, Carlo AlbertoScrignoli, FrancescoFregni, PaoloGaioli, SimoneFranceschini, GiovanniBarater, Davide
As engines become lighter and achieve higher output to meet carbon dioxide emissions targets, it becomes more challenging to design a crankshaft that is both lighter and capable of handling higher loads. Therefore, it is necessary to understand the characteristics of forces imposed on the crankshaft, and the mechanisms by which stresses are created in the crankshaft. This paper describes the characteristics of bending stresses measured on the rearmost crank pin fillet of a crankshaft. Two basic crankshaft resonant modes are described. Forward crankshaft whirl then has the effect of increasing the system natural frequencies by the stiffening effect, while reverse whirl reduces the system natural frequencies by the softening effect. The effect of whirl grows with increasing engine speed. This results in what appears to be four crankshaft natural frequencies rather than two. The four resonances appear at all non-zero engine speeds. The influence of flywheel mass on the stresses and
Kobayashi, Shinichiro
Linear engine alternator (LEA) design optimization traditionally has been difficult because each independent variable alters the motion with respect to time, and therefore alters the engine and alternator response to other governing variables. An analogy is drawn to a conventional engine with a very light flywheel, where the rotational speed effectively is not constant. However, when springs are used in conjunction with an LEA, the motion becomes more consistent and more sinusoidal with increasing spring stiffness. This avoids some attractive features, such as variable compression ratio HCCI operation, but aids in reducing cycle-to-cycle variation for conventional combustion modes. To understand the cycle-to-cycle variations, we have developed a comprehensive model of an LEA with a 1kW target power in MATLAB®/Simulink, and an LEA corresponding to that model has been operated in the laboratory. This MATLAB®/Simulink numerical model has been used to examine the sensitivity of the LEA
Bade, MeharClark, NigelFamouri, ParvizGuggilapu, PriyaankaDeviDarzi, MahdiJohnson, Derek
Recent technical advances have enabled flywheel energy storage systems (FESS) to become more compact and able to support higher-power applications. Due to their proven reliability, low cost of ownership, and favorable green environmental aspects, engineers and managers of data centers, hospitals, industrial systems, electric rail, and microgrid applications are reaping the benefits of clean energy storage that flywheels offer
Three-cylinder engines were launched, given the increasing demand for improved fuel economy and efficiency along with reduced friction and weight. Unlike four-cylinder engines, these engines are not naturally balanced. So, in order to compete with four-cylinder engines, some methods to solve this inherent weakness, such as balance shaft, mass unbalancing of flywheel and crankshaft pulley, or counterweights configuration (angular orientation and correction amount), have been used. Considering the undesirable characteristics of the balance shaft, such as cost, weight, friction, and noise, as well as dynamically inappropriate mass unbalancing method, this research proposes multi-objective optimization of counterweights to reduce vibrations. In this regard, after modeling a three-cylinder engine in constant speed and without the gas force effects, counterweights are optimized by non-dominated sorting genetic algorithm (NSGAII) method, to reduce shaking force, pitch and yaw moments, and
Mohammadi, SomayeOhadi, AbdolrezaKeshavarz, Reza
Gear oscillations are one of the most common sources of Noise, Vibration and Harshness (NVH) issues manifested in automotive powertrains. These oscillations are generated mainly due to impacts of the meshing gear teeth over a broad frequency range. To mitigate NVH phenomena, automotive manufacturers traditionally couple linear tuned vibration absorbers to the driveline. Common palliatives used are clutch dampers and dual mass flywheels, which generally suppress vibrations effectively only over narrow frequency bands. Nonlinear Energy Sinks (NESs) are a class of vibration absorbers with essentially nonlinear characteristics that are designed for dissipating vibration energy over broad frequency ranges (due to the employed nonlinearity). The NES does not have a preferential natural frequency; this is rather characterized by the nonlinear stiffness. An NES functions on the principle of transferring energy between the primary system (e.g. driveline) and the absorber in two ways: (i) the
Friskney, BrettMotato PhD, EliotHaris, AhmedMohammadpour, MahdiTheodossiades, Stephanos
In this work, the bearing loads of a flywheel-based kinetic energy recovery system caused by gyroscopic torques and dynamic forces during vehicle maneuvering are investigated. This paper is a follow-up study to a preliminary investigation where the flywheel was assumed to be rigidly supported, thus neglecting the effect of rotor precession. At finite stiffnesses of real bearings, however, the flywheel is enabled to move, due to the compliance of the bearing itself, relative to the vehicle chassis with high angular velocities. Based on the equations for elastic rotor-platform interactions, which relate the vehicle’s roll, pitch and yaw rate with the internal transverse torques acting on the elastically supported flywheel, the radial bearing loads are re-investigated in this work for some selected standardized driving maneuvers. The simulation results of the present work are consistent with the results of the rigid model, provided that the elastic approach is subjected to high bearing
Zwölfer, AndreasBischof, Günter
The application of fluid power technology in the United States is widespread, seeing use in industries as diverse as dentistry, military vehicles, and mining. Fluid power is also attracting interest in hybrid vehicle applications, which require an energy storage component. While most hydraulic energy storage is accomplished using hydraulic accumulators, energy storage flywheels also provide an attractive alternative for use in mobile hydraulic systems. The main difference between the system architectures proposed in literature has been whether to include distinct, separate hydraulic pump/motors for the engine and the flywheel. Previous studies have compared the various topographies to traditional drivetrains, using both numerical simulation and experimentation, with favorable results. This study uses numerical simulation based on previously validated models to directly compare performance for the prevalent flywheel hydraulic hybrid vehicle topologies to determine which topology
Cronk, PaulVan de Ven, James
A four-chamber Otto cycle rotary engine, the Szorenyi Rotary Engine, has been invented and developed by the Rotary Engine Development Agency (REDA) in Melbourne, Australia. The engine concept has been awarded a U.S. Patent (Number 6,718,938 B2). A prototype engine has been constructed and a successful proof-of-concept engine test was achieved in 2008. The stator of the Szorenyi engine is a similar shape to a Wankel engine. However, the geometric shape of the engine rotor is a rhombus, which deforms as it rotates inside the contour of the mathematically defined stator. This geometry translates to a rotary engine with four combustion chambers. Each revolution of the crankshaft produces one revolution of the rotor; a complete engine cycle in each of the four chambers; and therefore four power strokes. In contrast, the Wankel engine produces one power stroke per crankshaft revolution. Additionally, the Wankel engine is rev limited due to the excessive crankshaft bending resulting from the
King, Peter
This SAE Standard describes a procedure to be used to evaluate a disturbance known as “idle gear rattle” which can exist in vehicles equipped with manual transmissions and clutches. Other types of noises associated with operation at idle are also briefly described
Truck and Bus Powertrain Committee
Although not limited to, these flywheels are normally used on trucks considered as Medium-Duty (Class 6 and 7), as well as Heavy-Duty (Class 8) trucks
Truck and Bus Powertrain Committee
Although not limited to, these clutches are normally used on trucks considered as Medium-Duty (Class 6 and 7), as well as Heavy-Duty (Class 8
Truck and Bus Powertrain Committee
Since the sizes of the flywheel and clutch have been enlarged due to downsizing of diesel engines, the mass and moment of inertia at the crankshaft rear end have increased. Consequently, the serious bending stresses have appeared in the crankshaft rear. This paper describes the characteristics of those serious bending stresses, based on the mechanism for whirl resonance. The whirl resonance is largely impacted by the mass of the flywheel and clutch and by the distance from the crank-journal center of the rear end to the center of gravity of the flywheel and clutch
Kimura, JoujiTanaka, TatsuyaHakomoto, KenjiroKawase, KousukeKobayashi, Shinichiro
At present, a Dual Mass Flywheel (DMF) system is widely known to provide benefits on driveline induced noise, vibration and drivability over a Single Mass Flywheel (SMF). A well-tuned DMF provides nice isolation of torsional vibrations generated in periodic combustion process of automobile IC engines. Similarly, a torsional vibration damper mounted on driveline component reduces the torsional excitation and results a lower torsional vibration at driveline components. Noise and vibration issues like boom noise and high vibrations at low engine RPM range drive are often resulted due to high engine firing order torsional excitation input to the driveline. More often, this becomes one of the most objectionable noise and vibration issues in vehicle and should be eliminated or reduced for better NVH performance. A 4 cylinder, 4 stroke small diesel engine equipped with SMF is found to have high engine firing order torsional excitation. The engine is chosen to carry out a comparative study of
Gupta, KapilChoudhary, ArunBidre, Rakesh
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