Investigation of a Passenger Cars Dynamic Response due to a Flywheel Based Kinetic Energy Recovery System - Research Proposal Example

INVESTIGATION OF A PASSENGER CAR’S DYNAMIC RESPONSE DUE TO A FLYWHEEL BASED KINETIC ENERGY RECOVERY SYSTEM : Submission Date: Purpose of the study Flywheel-based kinetic energy recovery system is used in most modern automotive applications to perform defined purposes of recovering moving vehicle’s kinetic energy in cases where the car in question will have its breaks applied [1 & 2]. It would however be appreciated that even though kinetic energy recovery system (KERS) is not a new concept, using flywheel for this purpose remains relatively new as the use of high voltage batteries had largely been used for the storage of recovered energy [3]. Valid claim can be made to for the popularity of flywheel-based (KERS) based on several reasons including the commercial use of 24cm diameter flywheel which comes with the weight of 5000g and performs revolution to the tune of 64,500 rpm [4]. This popularity notwithstanding, not much seems to have been covered by way of empirical research on the dynamic response of passenger vehicles when argued with reference to gyroscopic effects of these vehicles [4]. This identified gap forms the basis for the purpose of the proposed study which seeks to investigate the influence of flywheel-based KERS for the dynamic response of an average passenger vehicle. Background Many researchers have commented on the factors leading to the growing reliance on KERS, citing the need to guarantee improved fuel efficiency and reduced emissions as some of the most crucial advantages that the system offers [22]. This is because the overall functioning of the KERS, particularly the high-speed flywheel is based on the ability to internally utilise energy that would have otherwise gone wasted or unused. For this to be possible, the KERS performs a multiplicity of functions including the recovery, storage and reapplication of vehicle kinetic energy which would have gone waste whiles applying brakes [16]. In recent times, the real concern of most automotive system developers has been to differentiate between KERS platforms that function well for electrical hybrid systems as against mechanical hybrid systems. This is because of the growing penetration levels of these two hybrid systems on the market even though their mechanisms for recovering kinetic energy under braking are different [15]. In this, [10] observed the use of chemical battery or ultracapacitors as the preferred platform for performing the functionalities of KERS in electrical hybrid systems as against the use of flywheel in mechanical hybrid systems. From the premise developed above, it would be noted that the emphasis of the study shall be on mechanical hybrid systems, where particular reference shall be made to passenger car. The issue of a vehicle’s dynamic response under flywheel-based KERS has been of particular importance in literature. the reason for this is that apart from the fact that these cars have systems which uses a flywheel for their major energy storage device, they also rely on variable transmission to actually control and transfer the energy to and from the driveline [4]. Meanwhile, for such combined energy utilisation, it is always important that the storage systems in question would have some qualities such as energy density resistance, robustness and simplicity in operation that can accommodate KERS functionality [4]; [19]. However, [11] noted it is electrical energy storage systems rather than mechanical energy systems that possess these qualities even though the former lacks recharge efficiency. The absence of energy density resistance, robustness and simplicity in operation makes is the background based on the proposed study is being performed. This is because it is important to know how the absence of these qualities in flywheel-based KERS affects dynamic response of passenger cars as influence by gyroscopic effects. Research questions Based on the given background and in order to achieve the purpose of the study, the researcher has set some questions which will be pursued through the research methods and techniques. 1. What safety issues accompany the use of flywheel-based KERS given the high rotational speed of flywheel? 2. What is the influence of gyroscopic effects in flywheel-based KERS on vehicle dynamics? 3. How does the equation of motion of a gyroscope explain a passenger car’s dynamic response? Methods and techniques The overall method that will be used in achieving the study’s purpose is the simulation of passenger vehicle’s dynamic response under the influence of flywheel-based KERS. This means that a desk-based experimentation technique will be used in implementing the research as used in similar studies as [13, 8, 20, and 14]. Ahead of the simulation, there will be the derivation of the gyroscopic torques to be used in determining “effects of the vehicle’s motion on the flywheel, and its reactive gyroscopic forces exerted back on the vehicle” [4, p. 203]. The derivation of gyroscopic torques will be performed with the use of equations which help to establish the transverse torques acting on the spinning rotors of the vehicle to cause rotation about its centre of mass [18]. [4] developed a similar equation using a 3 x3 unit matrix to constitute the moment of inertia tension Ir as found in the flywheel. This inertia tension was made up of transverse inertia It and axial inertia Is to define the resistant changes in rotational speed based on the flywheel’s moment of inertia [4, 12]. [9] observed that relationship between energy transferred to the flywheel and rotational speed by stating that gyroscopic torques can be applied to increase these rotational speed. It is for this reason that the equation as given below puts emphasis on rotational speed and thus moment of inertia. Ir = From the equation above, transverse inertia is It and axial inertia is Is. With the moment of inertia tension established, KERS will be integrated in a simulation built in the passenger car to know its dynamic response based on flywheel-based KERS as was in the case in [4; 5; and 7]. The simulation will be based on the veDYNA model which uses the Jourdian’s principle [17]. Based on the model, the two brake pads are assumed to produce brake torque at each wheel [4]. This technique helps to define the energy recovery strategy that will be produced under regenerative braking. As part of the simulation therefore, a typical Cambridge Passenger/Commercial Vehicle Kinetic Energy Recovery System (CPC-KERS) will be chosen with a path that has already been described, and a target speed profile reviewed instead of preview control strategy as was the case in [4]. This will be done as part of the basic driver without preview algorithm as used in [4]. Different driving manoeuvres such as straight-line driving, ISO 3888 lane change, ISO 7975 braking in a turn, and speed bump will then be applied on the selected vehicle. As these different driving manoeuvres are performed, their dynamic response will be calculated from the computer simulations based on the gyroscopic torque equation. Motivation My motivation for taking the PhD course is to help me gain an elevation in my academic knowledge and experience, which can help me become a useful engineer after school. With the changing dynamics of the engineering and construction industry, it is very important that a person who wants to succeed in the industry have the relevant knowledge base that meets the present demand on the market. In my estimation, one of the best ways to accomplish this is to take up some of the highest levels of learning such as the PhD program. Indeed, ever since I started the course, I have gained multiple skill and ability in several areas of engineering. My motivation for selecting the current institution was based on a longstanding track record it has as training several reputable engineers of our day. I was enthused to learn about testimonials from previous graduates on their website and I must confess that my expectation has been met ever since I started the PhD. What has been particularly outstanding about the university is its dedicated and supportive faculty base who offers maximum assistance to students in helping them maximise their potentials. 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(2010). “Modeling of engine and vehicle for a compact car with a flywheel based kinetic energy recovery systems and a high efficiency small diesel engine” SAE Technical Paper 2010-01-2184.Warrendale (PA): SAE International. [7] Brockbank C & Greenwood C (2010). “Fuel economy benefits of a flywheel & CVT based mechanical hybrid for city bus and commercial vehicle applications” SAE Int J Commer Veh. Vol. 2 No. 2, pp. 115–122. [8] Chucholowski C, Vögel M, Stryk O,Wolter TM (1999). Real time simulation and online control for virtual test drives of cars. In: Bungartz H-J, Durst F, Zenger C, editor. High Performance Scientific and Engineering Computing. Berlin: Springer; p. 157–166. [9] Cross D & Brockbank C. (2009). “Mechanical hybrid system comprising a flywheel and CVT for motorsport and mainstream automotive applications” SAE Technical Paper 2009-01-1312. Warrendale (PA): SAE International. 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[17] Moro D, Cavina N, Trivi´c I & Ravaglioli V. (2010). “Guidelines for integration of kinetic energy recovery system (KERS) based on mechanical flywheel in an automotive vehicle” SAE Technical Paper 2010-01-1448.Warrendale (PA): SAE International. [18] Post R. (1996). “A new look at an old idea – the electromechanical battery” Sci Technol Rev. 4, pp. 12–19. [19] Pressl MC (2003). Internal torques and forces in gyrostats with magnetically suspended rotors. Blacksburg (VA): Virginia Polytechnic Institute and State University. [20] Rill G. (2011). Road vehicle dynamics: fundamentals and modeling. Boca Raton, FL: CRC Press Inc. [21] Schilke NA, Dehart AO, Hewko LO, Matthews CC, Pozniak DJ & Rohde SM. (1984). “The design of an engine-flywheel hybrid drive system for a passenger car” SAE Technical Paper 841306. Warrendale (PA): SAE International. [22] Yoshihiro S, Junhoi H, Masahiko A, Lin S, Takahata R & Mukaide N (2013). “Study on rollover prevention of heavyduty vehicles by using flywheel energy storage systems” Proceedings of the FISITA 2012 World Automotive Congress, Lecture Notes in Electrical Engineering. Vol. 197, pp. 693–701. Read More