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ICICLE: A Model for Glaciated & Mixed Phase Icing for Application to Aircraft Engines

Rolls-Royce Plc-Geoffrey Jones, Benjamin Collier
University of Oxford-Alexander Bucknell, Matthew McGilvray, David Gillespie, Xin Yang
Published 2019-06-10 by SAE International in United States
High altitude ice crystals can pose a threat to aircraft engine compression and combustion systems. Cases of engine damage, surge and rollback have been recorded in recent years, believed due to ice crystals partially melting and accreting on static surfaces (stators, endwalls and ducting). The increased awareness and understanding of this phenomenon has resulted in the extension of icing certification requirements to include glaciated and mixed phase conditions. Developing semi-empirical models is a cost effective way of enabling certification, and providing simple design rules for next generation engines. A comprehensive ice crystal icing model is presented in this paper, the Ice Crystal Icing ComputationaL Environment (ICICLE). It is modular in design, comprising a baseline code consisting of an axisymmetric or 2D planar flowfield solution, Lagrangian particle tracking, air-particle heat transfer and phase change, and surface interactions (bouncing, fragmentation, sticking). In addition, an efficient particle tracking method has been developed into the code, which employs the representative particle size distribution at each injection location and a deterministic particle sticking method by using an in-situ particle based…
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Gasoline Fueled Pre-chamber Ignition System for a Light-Duty Passenger Car Engine with Extended Lean Limit

SAE International Journal of Engines

Technische Universitat München, Germany-Andreas Stadler, Maximilian Wessoly, Sebastian Blochum, Martin Härtl, Georg Wachtmeister
  • Journal Article
  • 03-12-03-0022
Published 2019-06-07 by SAE International in United States
In this work, a light-duty research engine based on a passenger car engine is equipped with an in-house developed pre-chamber (PC) ignition system replacing the conventional spark plug. By using such kind of ignition system, the combustion in the main chamber is enhanced by radical seeding through jets travelling from the pre-chamber to the main chamber. These radicals serve as high-energy ignition sites for the mixture in the main combustion chamber leading to enhanced burn rates and combustion speed. In contrast to conventional spark-ignited combustion starting from the spot of the electrode gap, an extended lean misfire limit and a mitigated knocking tendency are achieved. The presence of a gasoline direct injector inside the PC enables the system to operate in both passive and active modes. The injection of a small fuel amount allows separating the air-to-fuel equivalence ratio of the pre-chamber and the main chamber. By this, an overall lean mixture is ignited by providing a stoichiometric mixture near the PC spark plug. In this study, different orifice nozzles of the PC are investigated…
 
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Process Regulations and Mechanism of WEDM of Combustor Material

National Institute of Technology, Kurukshetra, India-Bhupinder Singh, Joy Prakash Misra
  • Journal Article
  • 01-12-01-0004
Published 2019-06-07 by SAE International in United States
This study discusses the experimental investigation on WEDM of combustor material (i.e., nimonic 263). Experimentation has been executed by varying pulse-on time (Ton), pulse-off time (Toff), peak current (Ip), and spark gap voltage (Sv). Material removal rate (MRR), surface roughness (SR), and wire wear rate (WWR) are employed as process performance characteristics. Experiments are designed as per the box-Behnken design technique. Parametric optimization has also been performed using response surface methodology. Besides this, field-emission scanning electron microscope (FE-SEM) and an optical microscope are utilized to characterize WEDMed and worn-out wire surfaces. It is observed that both surfaces contain micro-cracks, craters, spherical droplets, and a lump of debris. Furthermore, the mechanism of recast layer formation has been critically evaluated to apprehend a better understanding of the technique. The key features of the experimental procedure are also highlighted.
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Benefit of a Lightweight Frunk

Autoneum Management AG-Federico Di Marco, Flavio Pezzani, Andreas Daving, Luca Mazzarella
Published 2019-06-05 by SAE International in United States
Due to the increasing number of battery electric vehicles (BEVs), the engineering fields regarding driving comfort and NVH issues are becoming more and more challenging: many new factors affect the development of BEVs NVH package. The noise sources related to the powertrain are different from the traditional ones of internal combustion engines, for instance due to the presence of tonal components, strong harmonics and potential whining noise.To satisfy NVH specifications and the need for lightweight solutions to increase driving range, it is important to mask as much as possible the noise coming from the engine bay with materials both lightweight and acoustically performing. Moreover, for electric vehicles new interesting solutions are possible with the introduction of new components that do not find room under the hood of ICE or hybrid vehicles. These components, if properly designed, could lead to significant NVH benefits. The present paper reports the NVH effects of one of these new components, the frunk, a small compartment inside the engine bay, functionally similar to the trunk.In this paper, the design-by-simulation of a…
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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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Noise and Vibration End-of-Line Production Testing and Analysis Challenges

Bruel & Kjaer North America, Inc.-Chris Moon
Published 2019-06-05 by SAE International in United States
Theoretical modeling continues to play a larger role in noise and vibration engineering; however, until products are perfectly made, there will be a need to evaluate their end of the production line performance. Manufacturing production of a wide range of items has classically involved some amount of subjective and/or evolved objective quality testing along, or at the end of the production line. This testing can have goals of determining product safety, durability, functionality, and/or the vibration/sound quality. A vibration-based measurement approach is frequently used for many of those goals. Often, many modern products utilize some combination of electric motors, internal combustion engines, and power transmission rotational components. The end-of-line testing for many of these rotational components is after many years now heavily refined in the measurement and analysis methods, and the separation of good, bad and marginally bad samples may not always be challenging. It is frequently the non-standard types of products or unique operating conditions, either as subcomponents or assemblies, which may provide unique challenges to the typical measurement and analysis methods. Additionally, depending…
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Structure-Borne Path Identification of Rumbling Noise in a Passenger Car Based on In-Situ Blocked Force Transfer Path Analysis

Hyundai & Kia Corp.-Doohee Han
Hyundai Motor Group-Insoo Jung
Published 2019-06-05 by SAE International in United States
It is known that the major source of rumbling noise the combustion force of an engine. The combustion force excites the engine and induces vibrations of the powertrain. These vibrations are then transferred to the body of the vehicle via its structural transfer path. Moreover, the vibrations of the vehicle’s body emit internal vibra-acoustic noise. This noise is often referred to as the rumbling noise due to the structural borne path. If there are structural resonances among the structural paths such as the engine, transmission, mount bracket, suspension, and the vehicle’s body, the rumbling noise could be amplified. To identify the major resonances of the structural transfer path, classical transfer path analysis (CTPA) has been traditionally utilized. The method has a significant limitation in that it is necessary to decouple the substructures to obtain the contact force between individual components and to identify the transfer path of the structure-borne sound. Recently, blocked force transfer path analysis (BF-TPA) was introduced and this approach does not require the decoupling of the substructures. In this study, we identify…
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A Case Study on Golf Car Powertrain NVH Sources and Mitigation Methods

Club Car, LLC-Adam Clark
Roush Industries, Inc.-Steven Carter, Kenneth Buczek, Mayuresh Pathak
Published 2019-06-05 by SAE International in United States
The golf market has remained flat in North America. Whereas, it has grown worldwide. A trend is seen where the number of young adults and adults over the age of 65 years involved with the game has increased. The demographics in golf showing the most growth also have high standards for the operation of the golf car. They have transcended their expectations to align with some of the qualities expected of automobiles. There is a shift in consumer expectations. Moreover, the market competition has also increased. This drives the OEMs to deliver refined golf cars with NVH being a key aspect in development. This paper showcases a recent study to improve the powertrain N&V performance of an internal combustion engine golf car. Primarily, a test-based approach is followed. Chassis rolls and on road testing are performed for benchmarking and target setting. System and component tests are performed to root cause issues. The tests further help to provide input for mitigation methods for application on the golf cars. Structural modifications address structure-borne noise and perceived vibration.…
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On the Measurement and Simulation of Flow-Acoustic Sound Propagation in Turbochargers

FEV Europe GmbH-Ralf Stienen
Institute for Combustion Engines, RWTH Aachen University-Hendrik Ruppert, Felix Falke, Stefan Pischinger, Marco Günther
Published 2019-06-05 by SAE International in United States
Internal combustion engines are increasingly being equipped with turbochargers to increase performance and reduce fuel consumption and emissions. Being part of exhaust and intake systems, the turbocharger strongly influences the orifice noise emission. Although 1D-CFD simulations are commonly used for the development of intake and exhaust systems, validated acoustic turbocharger models are not yet state-of-the-art. Consequently, the aim of the paper is the investigation of the turbocharger’s influence on the orifice noise and the development of an accurate 1D-CFD model.The passive acoustic transmission loss was measured for a wide operating range of four turbochargers, including wastegate and VTG-system variations. Low frequency attenuation is dominated by impedance discontinuities, increasing considerably with mass flow and pressure ratio. High frequency transmission loss is generated by destructive interferences in the stator, which depend on the stator mass flow distribution and the turbocharger size.A new generic turbocharger model was developed to model both low frequency impedance discontinuities and high-frequency interferences by linking an idealized stator geometry with potential sources and turbocharger performance maps. In this way, high acoustic and thermodynamic…
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Test and Analysis of Electromagnetic Noise of an Electric Motor in a Pure Electric Car

Geely Automoile Research Institute-Qiang Kang, Perry Gu, Chao Gong
Tongji University-Shuguang Zuo
Published 2019-06-05 by SAE International in United States
Compared with the low-frequency ignition order of mechanical and combustion noise of an internal combustion engine, the noise of electric drive assembly of electric vehicles is mainly the high-frequency whining noise generated by electromagnetic forces of motors and gear meshing of reducers, as well as the high-frequency umbrella-shape noise generated by DC/AC pulse width modulation. Although the radiated sound power of these high frequency noise is far less than that of an internal combustion engine, the high frequency noise of the motor and the reducer is subjectively quite annoying. This paper studies the characteristics of electromagnetic noise of a permanent magnet synchronous motor in an electric car. By testing and analyzing of noise sources of an electric motor in the car and on a test rig, the spatial order characteristics and amplitude-frequency characteristics of the electromagnetic forces are revealed. The noise orders are multiples of the number of motor poles. The most critical order is 48th order, and its spatial order is 0th order. The peak of this 48th order is due to the stator’s…
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