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Design and Fabrication of CFRP Wheel Centre for FSAE Race-Car

VIT-Sangeet Aggarwal, Renold Elsen
  • Technical Paper
  • 2019-28-0117
Published 2019-10-11 by SAE International in United States
In this work, a Carbon Fibre Reinforced Polymer (CFRP) Wheel Centre (WC) is designed targeting key parameters such as reduced un-sprung mass and lower rotational inertia in vehicle dynamics. A Keizer Aluminium Wheel Centre was used by the team previously and it weighed around 1.8 Kg. Designing of CFRP Wheel Centre was based on previously used Keizer Aluminium wheel centre considering the design constraints such as distance between hub and wheel assembly. This was done to ensure the same trackwidth within the Formula Student rules. Initially, the Finite Element Analysis (FEA) was carried out for the Keizer Aluminium wheel centre and the results were analysed. For the same design CFRP material was used and the result was found out to be promising with a wheel centre weight of 1.3 Kg. Further to improve the performance and weight reduction, FEA was done to design a 38 layered CFRP wheel centre giving utmost priority to ease of manufacturability and safe design. After manufacturing, the CFRP wheel centre weighed 950g and was implemented on PRV17 (Pravega Racing’s FSAE…
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Performance Evaluation of an Electric Vehicle with Multiple Electric Machines for Increased Overall Drive Train Efficiency

University of Ljubljana-Mario Vukotić, Damijan Miljavec
University of Rome Niccolò Cusano-Laura Tribioli, Daniele Chiappini
Published 2019-10-07 by SAE International in United States
Proposed solutions for electric vehicles range from the simple single-motor drive coupled to one axle through a mechanical differential, to more complex solutions, such as four in-wheel motors, which ask for electronic torque vectoring. Main reasons for having more than one electric machine are: reduction of the rated power of each motor, which most likely leads to simplification and cost reduction of all the electric drive components; increased reliability of the overall traction system, enhancing fault tolerance ability; increase of the degrees of freedom which allows for control strategy optimization and efficiency improvement. In particular, electrical machines efficiency generally peaks at around 75% of load and this usually leads to machine downsizing to avoid operation in low efficiency regions. The same output performance can be achieved by using two or more electrical machines, rather than only one, of smaller size and running them at unequal load - one of the machines at higher load and the other(s) at lower load.In this paper, the performance of an electric vehicle with multiple electric machines is analyzed to…
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Axial Flow Turbine Concept for Conventional and e-Turbocharging

Brunel University-Apostolos Pesyridis
Universita di Napoli Federico II-Alessandro Cappiello, Raffaele Tuccillo, Maria Cristina Cameretti
Published 2019-09-09 by SAE International in United States
Engine downsizing has established itself as one of the most successful strategies to reduce fuel consumption and pollutant emissions in the automotive field. To this regard, a major role is played by turbocharging, which allows an increase in engine power density, so reducing engine size and weight. However, the need for turbocharging imposes some issues to be solved. In the attempt of mitigating turbo lag and poor low-end torque, many solutions have been presented in the open literature so far, such as: low inertia turbine wheels and variable geometry turbines; or even more complex concepts such as twin turbo and electrically assisted turbochargers. None of them appears as definitive, though.As a possible way of reducing turbine rotor inertia, and so the turbo lag, also the change of turbine layout has been investigated, and it revealed itself to be a viable option, leading to the use of mixed-flow turbines. Only recently, the use of axial-flow turbines, with the aim of reducing rotor inertia, has been proposed as well.The current paper documents a case study involving the…
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Valve Flow Coefficients under Engine Operation Conditions: Piston Influence and Flow Pulsation

FKFS-Michael Grill
University of Stuttgart-Sven Fasse, Michael Bargende
Published 2019-09-09 by SAE International in United States
Engine valve flow coefficients are used to describe the flow throughput performance of engine valve/port designs, and to model gas exchange in 0D/1D engine simulation. Valve flow coefficients are normally determined at a stationary flow test bench, separately for intake and exhaust side, in the absence of the piston. However, engine operation differs from this setup; i. a. the piston might interact with valve flow around scavenging top dead center, and instead of steady boundary conditions, valve flow is nearly always subjected to pressure pulsations, due to pressure wave reflections within the gas exchange ports. In this work the influences of piston position and flow pulsation on valve flow coefficients are investigated for different SI engine geometries by means of 3D CFD and measurements at an enhanced flow test bench. In the past, most research work on valve flow coefficients left aside possible piston influence and, for dynamic boundary conditions, it largely omitted subtraction of the gas inertia effects, which are already covered by 1D simulation. In this work, concerning piston influence, various valve overlap…
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Model Verification of CAE with NVH-Test Acting on Downsized Car Engines

NVH-testing Powertrain-Janos Ribarits
Volvo Cars, Engine Vibrations CAE-Urban Rönnqvist
Published 2019-06-05 by SAE International in United States
Today’s trend of combustion engine development for cars is characterized with; high torque, low engine speed, low weight, high degree of cyclic irregularity, low excitation frequency due to fewer cylinders active e.g. 4-cylinder or less.This implies in respect of vibrations that it is crucial to control powertrain rigid body modes and place these were they cannot be reached and induced by the low exciting harmonic frequencies for low engine speeds or idling. It is also important to control the overall flexible vibration modes.A mathematical CAE model is created in simulation software AVL-EXCITE in order to handle the vibration phenomenon as a first step. But it is absolutely necessary to “verify” these models with real measurements in respect of NVH and if needed upgrade the CAE model if there are detected deviations. The NVH-test is done with testing tool DEWESoft.The purpose of below paper is to do model verification on a concrete example in respect of powertrain vibrations. Volvo Cars in-line 4-cylinder VEA diesel engine in rig installation is the object for the paper of model…
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Vibro-Acoustic Analysis for Modeling Propeller Shaft Liner Material

General Motors-Rajith R. Jayaratne, Yu Liu, Mark Gehringer, Jeff Rayce, Wallace Hill
Published 2019-06-05 by SAE International in United States
In recent truck applications, single-piece large-diameter propshafts, in lieu of two-piece propshafts, have become more prevalent to reduce cost and mass. These large-diameter props, however, amplify driveline radiated noise. The challenge presented is to optimize prop shaft modal tuning to achieve acceptable radiated noise levels. Historically, CAE methods and capabilities have not been able to accurately predict propshaft airborne noise making it impossible to cascade subsystem noise requirements needed to achieve desired vehicle level performance. As a result, late and costly changes can be needed to make a given vehicle commercially acceptable for N&V performance prior to launch.This paper will cover the development of a two-step CAE method to predict modal characteristics and airborne noise sensitivities of large-diameter single piece aluminum propshafts fitted with different liner treatments. The first step is the use of a traditional CAE software to calculate prop surface response. The second step is a boundary element simulation to calculate prop surface radiated noise under the excitation obtained from the first step. Finally, acceleration and acoustic test data are presented to assess…
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Reducing Vehicle Interior NVH by Means of Locally Resonant Metamaterial Patches on Rear Shock Towers

KU Leuven - DMMS lab, Flanders Make-Luca Sangiuliano, Claus Claeys, Elke Deckers, Bert Pluymers, Wim Desmet
MotionS lab, Flanders Make-Jasper De Smet
Published 2019-06-05 by SAE International in United States
Stringent regulations for CO2 emissions and noise pollution reduction demand lighter and improved Noise, Vibration Harshness (NVH) solutions in automotive industries. Designing light, compact and, at the same time, improved NVH solutions is often a challenge, as low noise and vibration levels often require heavy and bulky additions, especially to be effective in the low frequency regime. Recently, locally resonant metamaterials have emerged among the novel NVH solutions because of their performant NVH properties combined with lightweight and compact design. Due to the characteristic of stop band behavior, frequency ranges where free wave propagation is inhibited, metamaterials can beat the mass law, be it at least in some tunable frequency ranges. Previously the authors demonstrated how metamaterials can reduce the vibrations in a simplified shock tower upon shaker excitation. In this work, the authors apply the metamaterial concept on the real rear shock towers of a vehicle. In order to be able to benchmark the solution, a test vehicle is chosen, which is equipped in its commercial version with a 1.46 kg tuned vibration absorber…
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Assessment of Hydrotreated Vegetable Oil (HVO) Applicability as an Alternative Marine Fuel Based on Its Performance and Emissions Characteristics

SAE International Journal of Fuels and Lubricants

Norwegian University of Science and Technology, Norway-Sergey Ushakov, Nicolas Lefebvre
  • Journal Article
  • 04-12-02-0007
Published 2019-05-16 by SAE International in United States
In current study, the combustion and emission characteristics of hydrotreated vegetable oil (HVO) were studied and compared to those of conventional marine gas oil (MGO). The main goal was to verify its applicability as an alternative marine fuel. All experiments were performed using generator set and propeller-law test cycles, i.e., standardized E2 and E3 cycles respectively. Additional emphasis was paid to the particulate matter (PM) emissions combining gravimetric and particle number measurements. The obtained results indicate average 10-15 % reduction in nitrogen oxides (NOx) emissions, while total unburned hydrocarbons (THC) emissions were reduced by 50-55 %. It is believed that a much higher cetane number of HVO together with its superior chemical composition (overall higher H/C ratio, absence of aromatics and heavy-boiling compounds) plays a vital role here. This may also explain the observed around 30 % PM mass reduction, which however showed a strong dependence on load (fuel-air ratio) and speed (time available for combustion) settings. Measured particle size distributions showed a clearly unimodal nature for both the tested fuels with pronounced accumulation (soot)…
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Development of Two New High Specific Output 3 Cylinder Engines for the Global Market with Capacities of 1.2l and 1.5l

Mahle Powertrain Ltd.-Adrian Cooper, Andrew Stodart, David Hancock, Simon Duke, James Miller, Simon Reader
Published 2019-04-02 by SAE International in United States
MAHLE Powertrain has developed an industrialized version of its 3-cylinder downsizing engine as a low cost, high specific output engine, for the global automotive market. The engine has been developed in both 1.2 and 1.5 liter capacities, with the maximum commonality being maintained between the two variants. Through careful design, the engines are capable of delivering exceptionally high-specific torque and power outputs whilst utilizing only simple low-cost technology. At the same time the engines have also been engineered to meet the requirements of the latest Euro 6c and China 6a emissions standards. This was demonstrated very early in the project through use of a representative development vehicle. The 1.2 and 1.5 liter engines are rated at 30bar Brake Mean Effective Pressure (BMEP) and 100 kW/l and 28 bar BMEP and 94 kW/l respectively and are both capable of achieving these outputs whilst operating on 92 RON gasoline. The engines provide the capability of delivering competitive real-world fuel economy, which has been achieved through a combination of low friction design and reduced pumping losses, enabled by…
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A Systems Approach in Developing an Ultralightweight Outside Mounted Rearview Mirror Using Discontinuous Fiber Reinforced Thermoplastics

Clemson University-Sai Aditya Pradeep, Srikanth Pilla
Clemson University - ICAR-Senthil Raj Ramesh, Veera Aditya Yerra
Published 2019-04-02 by SAE International in United States
Fuel efficiency improvement in automobiles has been a topic of great interest over the past few years, especially with the introduction of the new CAFE 2025 standards. Although there are multiple ways of improving the fuel efficiency of an automobile, lightweighting is one of the most common approaches taken by many automotive manufacturers. Lightweighting is even more significant in electric vehicles as it directly affects the range of the vehicle. Amidst this context of lightweighting, the use of composite materials as alternatives to metals has been proven in the past to help achieve substantial weight reduction. The focus of using composites for weight reduction has however been typically limited to major structural components, such as BiW and closures, due to high material costs. Secondary structural components which contribute approximately 30% of the vehicle weight are usually neglected by these weight reduction studies. This work is an attempt to prove that composites can also be used effectively in the weight reduction of secondary structural components, while meeting the desired standards on mechanical performance, cost, and scalability.…
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