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Viewing 181 to 210 of 7824
2017-05-18
Journal Article
2017-01-9678
G Agawane, Varun Jadon, Venkatesham Balide, R Banerjee
Abstract Liquid sloshing noise from an automotive fuel tank is becoming increasingly important during frequent accelerating/decelerating driving conditions. It is becoming more apparent due to significant decrease in other noise sources in a vehicle, particularly in hybrid vehicles. As a step toward understanding the dynamics of liquid sloshing and noise generation mechanism, an experimental study was performed in a partially filled rectangular tank. A systematic study was performed to understand the effects of critical parameters like fill level and acceleration/deceleration magnitude. Response parameters like dynamic pressure, dynamic force, dynamic acceleration and sound pressure levels along with high speed video images were recorded. The proposed experimental setup was able to demonstrate major events leading to sloshing noise generation. These events in the sloshing mechanism have been analysed from the dynamic sensor data and correlated with high speed video images.
2017-04-11
Journal Article
2017-01-9625
Souhir Tounsi
Abstract In this paper, we present a design and control methodology of an innovated structure of switching synchronous motor. This control strategy is based on the pulse width modulation technique imposing currents sum of a continuous value and a value having a shape varying in phase opposition with respect to the variation of the inductances. This control technology can greatly reduce vibration of the entire system due to the strong fluctuation of the torque developed by the engine, generally characterizing switching synchronous motors. A systemic design and modelling program is developed. This program is validated following the implementation and the simulation of the control model in the simulation environment Matlab-Simulink. Simulation results are with good scientific level and encourage subsequently the industrialization of the global system.
2017-04-11
Journal Article
2017-01-9175
Yitao Zhu, Makarand Datar, Kalyan Addepalli, Natalie Remisoski
Nowadays, the vehicle design is highly ruled by the increasing customer demands and expectations. In addition to ride comfort and vehicle handling, the Noise, Vibration and Harshness (NVH) behavior of the powertrain is also a critical factor that has a big impact on the customer experience. To evaluate the powertrain NVH characteristics, the NVH error states should be studied. A typical NVH event could be decoupled into 3 parts: source, path, and receiver. Take-off shudder, which evaluates the NVH severity level during vehicle take-off, is one of the most important NVH error states. The main sources of Front Wheel Drive (FWD) take-off shudder are the plunging Constant Velocity Joints (CVJ) on the left and right half shafts. This is because a plunging CVJ generates a third order plunging force with half shaft Revolution Per Minute (RPM), which is along the slip of the plunging CVJ.
2017-04-11
Journal Article
2017-01-9627
André Lundkvist, Roger Johnsson, Arne Nykänen, Jakob Stridfelt
Abstract The objective of this study was to investigate if 3D auditory displays could be used to enhance parking assistance systems (PAS). Objective measurements and estimations of workload were used to assess the benefits of different 3D auditory displays. In today’s cars, PAS normally use a visual display together with simple sound signals to inform drivers of obstacles in close proximity. These systems rely heavily on the visual display, as the sound does not provide information about obstacles' location. This may cause the driver to lose focus on the surroundings and reduce situational awareness. Two user studies (during summer and winter) were conducted to compare three different systems. The baseline system corresponded to a system normally found in today’s cars. The other systems were designed with a 3D auditory display, conveying information of where obstacles were located through sound. A visual display was also available.
2017-03-28
Technical Paper
2017-01-1741
Hyerin Choi, JunHo Song, Jae kwang Lee, Jaeyong Ko
Abstract Recently, it is one of the major problems in the automotive industry that grating is occurred form the place that more than two different materials combined. It is the most severe case that the noise generates between automobile seats and other relative parts (or within seat parts). The purpose of this research verifies and suggests the way to reduce squeak noise between two different parts through the stick-slip test which is regulated by VDA. The two materials - the seat trim cover and the plastic - were selected as major factors. We conducted the test with two different types of seat trim cover (authentic and artificial leather) and plastics (PP and ABS) with 4 levels of embossing size (0 to 3, level ‘0’ is non-embossing. Level 1 is the biggest embossing and it goes through smaller. Level 3 is the smallest embossing size). Test results were reported with 1 to 10 Risk Priority Number (RPN) which was proposed by VDA (Verband der Automotilindustrie).
2017-03-28
Technical Paper
2017-01-0447
Zhe Li, Mike Dong, Dennis Harrigan, Michael Gardner
In gasoline Powertrain systems, the evaporative emission control (EVAP) system canister purge valve (CPV) can be actuated by pulse-width modulated (PWM) signals. The CPV is an electronically actuated solenoid. The PWM controlled CPV, when actuated, creates pressure pulsations in the system. This pulsation is sent back to the rest of the EVAP system. Given the right conditions, the fill limit vent valve (FLVV) inside the fuel tank can be excited. The FLVV internal components can be excited and produce noise. This noise can be objectionable to the occupants. Additional components within the EVAP system may also be excited in a similar way. This paper presents a bench test method using parts from vehicle’s EVAP system and other key fuel system components.
2017-03-28
Technical Paper
2017-01-0446
Xiao Chuan Xu, Xiuyong Shi, Jimin Ni, Jiaqi Li, Xiaochuan Xu Sr.
Abstract Oil pump is a critical part of engine lubrication system. The performance and efficiency of oil pump are greatly affected by vibration and noise, which would lead to the pump service life decreasing and pump body easily wearing. Hence the vibration and noise of oil pump is of great importance to study. In this paper, a FEA model of the variable displacement oil pump(VDOP) was established to carry on the modal and noise analysis, while the geometric structure was optimized with test verification. The modal analysis of VDOP was carried out by ABAQUS software, the 3-D unsteady flow field in VDOP was simulated by Pumplinx software, and the sound field was analyzed by ACTRAN acoustic module. Using a special oil pump test bench combined with B&K PULSE vibration and noise test equipment, the NVH and comprehensive performance experiment of the VDOP were carried out here.
2017-03-28
Technical Paper
2017-01-0445
Muthukumar Arunachalam, Arunkumar S, PraveenKumar Sampath, Abdul Haiyum, Yash Khakhar
Abstract In recent years, there is increasing demand for every CAE engineer on their confidence level of the virtual simulation results due to the upfront robust design requirement during early stage of an automotive product development. Apart from vehicle feel factor NVH characteristics, there are certain vibration target requirements at system or component level which need to be addressed during design stage itself in order to achieve the desired functioning during vehicle operating conditions. Vehicle passive safety system is one which primarily consists of acceleration sensors, control module and air-bag deployment system. Control module’s decision is based on accelerometer sensor signals so that its mounting locations should meet the sufficient inertance or dynamic stiffness performance in order to avoid distortion in signals due to its structural resonances.
2017-03-28
Technical Paper
2017-01-0448
Prakash T. Thawani, Stephen Sinadinos, John Zvonek
Abstract With the advent of EVs/HEVs and implementation of Idle-Stop-Start (ISS) technologies on internal combustion engine (ICE) driven cars/trucks to improve fuel economy and reduce pollution, refrigerant sub-system (RSS) induced noise phenomena like, hissing, gurgling and tones become readily audible and can result in customer complaints and concerns. One of the key components that induce these noise phenomena is the Thermostatic Expansion Valve (TXV). The TXV throttles compressed liquid refrigerant through the evaporator that results in air-conditioning (A/C) or thermal system comfort for occupants and dehumidification for safety, when needed. Under certain operating conditions, the flow of gas and/or liquid/gas refrigerant at high pressure and velocity excites audible acoustical and structural modes inherent in the tubing/evaporator/HVAC case. These modes may often get masked and sometimes enhanced by the engine harmonics and blower noise.
2017-03-28
Technical Paper
2017-01-0455
Harshad Hatekar, Baskar Anthonysamy, V. Saishanker, Lakshmi Pavuluri, Gurdeep Singh Pahwa
Abstract Structural elastomer components like bushes, engine mounts are required to meet stringent and contrasting requirements of being soft for better NVH and also be durable at different loading conditions and different road conditions. Silent block bushes are such components where the loading in radial direction of bushes are high to ensure the durability of bushes at high loads, but has to be soft on torsion to ensure good NVH. These requirements present with unique challenge to optimize the leaf spring bush design, stiffness and material characteristics of the rubber. Traditionally, bushes with varying degree of stiffness are selected, manufactured and tested on vehicle and the best one is chosen depending on the requirements. However, this approach is costly, time consuming and iterative. In this study, the stiffness targets required for the bush were analysed using static and dynamic load cases using virtual simulation (MSC.ADAMS).
2017-03-28
Technical Paper
2017-01-0449
Yinzhi He, Bin Wang, Zhe Shen, Zhigang Yang, Gunnar Heilmann, Tao Zhang, Guoxu Dong
Abstract Beamforming techniques are widely used today in aeroacoustic wind tunnels to identify wind noise sources generated by interaction between incoming flow and the test object. In this study, a planar spiral microphone array with 120 channels was set out-of-flow at 1:1 aeroacoustic wind tunnel of Shanghai Automotive Wind Tunnel Center (SAWTC) to test exterior wind noise sources of a production car. Simultaneously, 2 reference microphones were set in vehicle interior to record potential sound source signal near the left side view mirror triangle and the signal of driver’s ear position synchronously. In addition, a spherical array with 48 channels was set inside the vehicle to identify interior noise sources synchronously as well. With different correlation methods and an advanced algorithm CLEAN-SC, the ranking of contributions of vehicle exterior wind noise sources to interested interior noise locations was accomplished.
2017-03-28
Technical Paper
2017-01-0875
Valentin Soloiu, Jose Moncada, Martin Muinos, Aliyah Knowles, Remi Gaubert, Thomas Beyerl, Gustavo Molina
Abstract This paper investigates the performance of an indirect injection (IDI) diesel engine fueled with Bu25, 75% ultra-low sulfur diesel (ULSD#2) blended with 25% n-butanol by mass. N-butanol, derivable from biomass feedstock, was used given its availability as an alternative fuel that can supplement the existing limited fossil fuel supply. Combustion and emissions were investigated at 2000 rpm across loads of 4.3-7.2 bar indicated mean effective pressure (IMEP). Cylinder pressure was collected using Kistler piezoelectric transducers in the precombustion (PC) and main combustion (MC) chambers. Ignition delays ranged from 0.74 - 1.02 ms for both operated fuels. Even though n-butanol has a lower cetane number, the high swirl in the separate combustion chamber would help advance its premixed combustion. The heat release rate of Bu25 became initially 3 J/crank-angle-degree (CAD) higher than that of ULSD#2 as load increased to 7.2 bar IMEP.
2017-03-28
Technical Paper
2017-01-1121
Deb Bonnerjee, Djamel Bouzit, Javed Iqbal
Abstract Automobile customers are looking for higher performance and quieter comfortable rides. The driveline of a vehicle can be a substantial source of NVH issues. This paper provides an understanding of a driveline noise issue which can affect any variant of driveline architecture (FWD, AWD, RWD and 4X4). This metallic noise is mostly present during the take-off and appropriately termed as ting noise. This noise was not prevalent in the past. For higher fuel economy, OEMs started integrating several components for lighter subsystems. This in effect made the system more sensitive to the excitation. At present the issue is addressed by adding a ting washer in the interface of the wheel hub bearings and the halfshafts. This paper explains the physics behind the excitation and defines the parameters that influence the excitation. The halfshaft and the wheel hub are assembled with a specified hub nut torque.
2017-03-28
Technical Paper
2017-01-1122
Yashodhan V. Joshi
Abstract Vehicle noise has reduced over the years due to the customer demand for quieter vehicles. As the background noises such as combustion noise, pumping noise, etc. have reduced, mechanical noises such as gear noise have become prominent and a major cause of customer complaints. Engine timing gear train uses gears for transferring torque to cam and accessory gears. As engines have become quieter by efforts to reduce the combustion noise, as well as, by moving away from mechanical fuel pumps to common rail fuel pumps, the gear train noise has come under increased scrutiny. Gear whine could be a result of multiple factors. Gear profile distortion is one of the factors. Gear torque variation also has a significant effect on gear whine. Operation of the accessory drives such as hydraulic pumps under variable loads and speeds, is one of the major challenges for resolving a gear whine issue in the engine gear train.
2017-03-28
Technical Paper
2017-01-1125
Victor Baumhardt, Valdinei Sczibor
Abstract Halfshafts are very important components from vehicle powertrain. They are the element responsible to transmit torque and rotation from transmission to wheels. Its most basic design consists of a solid bar with joints at each extreme. Depending of bar length, the natural frequency of first bending mode might have a modal alignment with engine second order, resulting in undesired noise on vehicle interior. Many design alternatives are available to overpass this particular situation, like adding dampers, use tube shafts or use link-shafts, however, all of them are cost affected. This study proposes an investigation to obtain an optimal profile for a solid shaft, pursuing the lowest possible frequency for the first bending mode by changing its diameter at specific regions. The study is divided in four main stages: initially, a modal analysis of a halfshaft is done at vehicle to determinate its natural frequency when assembled on vehicle.
2017-03-28
Technical Paper
2017-01-1070
Da Shao, Xu Sichuan, Aimin Du
Abstract The electromagnetic valve actuator (EMVA) is considered a technological solution for decoupling between crankshaft and camshaft to improve engine performance, emissions, and fuel efficiency. Conventional EMVA consists of two electromagnets, an armature, and two springs has been proved to have the drawbacks of fixed lift, impact noise, complex control method and large power consumption. This paper proposes a new type of EMVA that uses voice coil motor (VCM) as electromagnetic valve actuator. This new camless valvetrain (VEMA) is characterized by simple structure, flexible controllable and low actuating power. VCM provides an almost flat force versus stroke curve that is very useful for high precision trajectory control to achieve soft landing within simple control algorithm.
2017-03-28
Technical Paper
2017-01-1145
Eric De Hesselle, Mark Grozde, Raymond Adamski, Thomas Rolewicz, Mark Erazo
Abstract Hybrid electric vehicles are continuously challenged to meet cross attribute performance while minimizing energy usage and component cost in a very competitive automotive market. As electrified vehicles become more mainstream in the marketplace, hybrid customers are expecting more attribute refinement in combination with the enhanced fuel economy benefits. Minimizing fuel consumption, which tends to drive hybrid powertrain engines to operate under lugging type calibrations, traditionally challenge noise, vibration, and harshness (NVH) metrics. Balancing the design space to satisfy the cost metrics, energy efficiency, noise and vibration & drivability under the hybrid engine lugging conditions can be optimized through the use of multiple CAE tools. This paper describes how achieving NVH metrics can put undesirable boundaries on Powertrain Operation which could affect other performance attributes.
2017-03-28
Technical Paper
2017-01-0376
Jianyong Liang, Jonathan Powers, Scott Stevens, Behrooz Shahidi
Abstract While Advanced High Strength Steels (AHSS) and the next generation AHSS grades offer improved crash safety and reduced weight for vehicles, the global stiffness and NVH performance are often compromised due to reduced material thickness. This paper discusses an advanced method of evaluating the joint effectiveness on contribution to global stiffness and NVH performance of vehicles. A stiffness contribution ratio is proposed initiatively in this research, which evaluates the current contribution of the joints to the global stiffness and NVH performance of vehicles. Another parameter, joint effectiveness factor, has been used to study the potential of each joint on enhancing the global stiffness. The critical joints to enhance the vehicle stiffness and NVH performance can be identified based on above two parameters, and design changes be made to those critical joints to improve the vehicle performance.
2017-03-28
Technical Paper
2017-01-1056
Rong Guo, Xiao-Kang Wei, Jun Gao
Abstract Manufacturers have been encouraged to accommodate advanced downsizing technologies such as the Variable Displacement Engine (VDE) to satisfy commercial demands of comfort and stringent fuel economy. Particularly, Active control engine mounts (ACMs) notably contribute to ensuring superior effectiveness in vibration attenuation. This paper incorporates a PID controller into the active control engine mount system to attenuate the transmitted force to the body. Furthermore, integrated time absolute error (ITAE) of the transmitted force is introduced to serve as the control goal for searching better PID parameters. Then the particle swarm optimization (PSO) algorithm is adopted for the first time to optimize the PID parameters in the ACM system. Simulation results are presented for searching optimal PID parameters. In the end, experimental validation is conducted to verify the optimized PID controller.
2017-03-28
Technical Paper
2017-01-1064
Mustafa Yıldırım
Abstract Engine design is crucial in terms of NVH. It is the sources of vibration for a vehicle. Nowadays engine tends to being smaller and less stiff and more powerful according to predecessor. Small engines with high power is inherently generates extreme force and vibrations and accordingly generates more noise. Thus engine structure and also engine main components should be designed to prevent this vibration. There are two main sources: One of them is combustion and other is inertia loads. Due to this sources engine structure can cause severe vibration and accordingly this can cause noise via transmitting it into vehicle with both structure and airborne. This paper focused on to reduce engine vibration level with changing the combustion inputs such as cylinder pressure parameters and inertia parameters like piston mass, conrod length and balancing parameters. Design of experiment is used to obtain most robust case in terms of NVH.
2017-03-28
Technical Paper
2017-01-1023
Yaqun Jiang, C. Hsieh, Georg Festag, Masood Ahmed, William Jiang
Abstract Large axial displacement at the edge of a flywheel causes a clutch to fail to disengage in high-speed rotation. To find out the root cause, a numerical procedure is proposed to investigate the vibration source and to understand dynamic behavior of the crank-train system. A simulation of the whole engine system including block, crankshaft, piston, and connecting rod was performed with AVL/Excite. The resulting CAE baseline model had good correlation with measurements. A comprehensive study was conducted for a set of flywheel and crankshaft models with different materials and unbalanced masses. The contribution to flywheel wobbling of each vibration order was carefully investigated, and an optimal design was presented.
2017-03-28
Technical Paper
2017-01-1487
Russ Norton, Ben Bulat, Ahmed Mohamed
Abstract A semi-active suspension system is designed to improve secondary ride by lowering damping levels while maintaining or enhancing primary ride control and vehicle handling. In order to provide optimized ride comfort, base damping levels are reduced. Reduced damping levels increase damaging loads through pothole events. The Road Load Mitigation (RLM) algorithm seeks to resolve the tradeoff of high damping levels required to control the vertical and horizontal spindle loads and the need for lower damping forces to improve secondary ride. As the base active damping forces are increased to control these loads, ride benefits or vehicle ride comfort is diminished. RLM looks at suspension velocity at all four corners independently to determine if a pothole signature is detected and requires compensation. Compensation is delivered quickly to reduce wheel drop into the pothole thereby reducing damaging loads.
2017-03-28
Technical Paper
2017-01-1231
Chun Tang, Natee Limsuwan, Nurani Chandrasekhar, Zhichun Ma, Jacob Krizan, Joel Hetrick, Wei Wu
Abstract The current of an electric machine driven by PWM switching inverter is not ideal sinusoidal, containing different levels of harmonics. The current harmonics have important impact on the electrical machine torque ripple which could translate into transmission and vehicle level Noise Vibration and Harshness (NVH). In this work, the current waveforms were measured from dyno test at prescribed torque and speed levels, and the electric machine torque ripple was computed with the measured current. This paper will focus on the investigation of the current harmonics behaviors and features at various torque and speed conditions, the impact on torque ripple, and the possible mitigation method to reduce torque ripple.
2017-03-28
Technical Paper
2017-01-1229
Ken Yamamoto, Nobuyasu Sadakata, Hidetoshi Okada, Yusuke Fujita
Abstract Electric oil pumps (EOP) for automobiles are used to lubricate and cool moving parts and supply oil pressure to components. Conventional EOPs consist of two separate units including a motor driver and a pump system comprised of a motor and a pump, which impedes layout flexibility for vehicles. To overcome this shortcoming, we have developed an ECU (electronic control unit)-integrated oil pump in which a driver, a motor and a pump are incorporated as a single unit. In the course of the project, we focused on improving vibration resistance and developing a compact design. The first challenge was to improve vibration resistance because of the driver located in close proximity to the powertrain. Since the driver is installed on the motor unit via electrically welded bus bars, the joints of the driver and the bus bar become susceptible to vibration.
2017-03-28
Technical Paper
2017-01-1061
Jiachen Zhai, Ma Conggan
Abstract Electric vehicle driving permanent magnet synchronous motor has a wide speed range and load changes, with abundant harmonic currents, and its eccentric form is complex, which all result in poor sound quality and abnormal noise problems becoming increasingly prominent. To make a systematic and thorough study of the centralized drive permanent magnet synchronous motor (PMSM) is significant to ameliorate the sound quality and solve noise problems. MATLAB-based modeling technology, SPSS software, and the establishment of sound quality evaluation model for the centralized drive PMSM has a crucial reference value on the research and development of the electric vehicle driving permanent magnet synchronous motor. As for the sound quality of centralized drive PMSM, firstly, in order to get objective parameter values, evaluation models of objective parameters based on psychological acoustics should be established after the collection of the sound samples.
2017-03-28
Technical Paper
2017-01-1057
Paul Zeng, Debabrata Paul, Vincent Solferino, Mark Stickler
1. Abstract Valvetrain ticking noise is one of the key failure modes in noise vibration harshness (NVH) evaluation at idle. It affects customer satisfaction inversely. In this paper, the root cause of the valvetrain ticking noise and key parameters that impact ticking noise will be presented. A physics based math model has been developed and integrated into a parameterized multi-body dynamic model. The analytical prediction has been correlated with testing data. Valvetrain ticking noise control is discussed.
2017-03-28
Technical Paper
2017-01-1059
Rong Guo, Jun Gao, Xiao-kang Wei
Abstract The active engine mount (AEM) is developed in automotive industry to improve overall NVH performance. The AEM is designed to reduce major-order signals of engine vibration over a broad frequency range, therefore it is of vital importance to extract major-order signals from vibration before the actuator of the AEM works. This work focuses on a method of real-time extraction of the major-order acceleration signals at the passive side of the AEM. Firstly, the transient engine speed is tracked and calculated, from which the FFT method with a constant sampling rate is used to identify the time-related frequencies as the fundamental frequencies. Then the major-order signals in frequency domain are computed according to the certain multiple relation of the fundamental frequencies. After that, the major-order signals can be reconstructed in time domain, which are proved accurate through offline simulation, compared with the given signals.
2017-03-28
Technical Paper
2017-01-1055
Baolin Yu, Zhi Fu, T. Bin Juang
Abstract The automotive industry is experiencing a profound change due to increasing pressure from environmental and energy concerns. This leads many automakers to accelerate hybrid and electric vehicle development. Generally hybrid and electric vehicles create less noise due to their compact engines (or no engine). However, customer satisfaction could be negatively impacted by the peak whine emitted by electric motor. Unlike conventional gas vehicles, the strategy for reducing motor whine is still largely unexplored. This paper presents an analytical study on electric motor whine radiated from the transmission in a hybrid vehicle. The analysis includes two stages. Firstly, a detailed finite element (FE) model of the transmission is constructed, and case surface velocities are calculated utilizing motor electromagnetic force. Then a boundary element model is built for evaluating noise radiated from the transmission surface using acoustic transfer vector (ATV) method.
2017-03-28
Technical Paper
2017-01-1052
Paul Zeng, Vincent Solferino, Mark Stickler
Abstract 1 Engine ticking noise is one of the key failure modes in today’s direct injection (DI) engines. High ticking noise results in high Things Gone Wrong (TGW) index, which negatively affects customer satisfaction. In this paper, the root cause of the ticking noise from DI injector in direct mounting will be presented. Design principle such as injector impact force to cylinder head and DI injector isolator design with 2 stage stiffness is proposed.
2017-03-28
Technical Paper
2017-01-1062
Abdelkrim Zouani, Gabriela Dziubinschi, Vidya Marri, Simon Antonov
Abstract In modern automotive engines, Variable Displacement Oil Pump (VDOP) is becoming the pump of choice to enable reduction in friction and delivery of stringent fuel economy. However, this pump creates pressure ripples, at the outlet port during oil pump shaft rotation, causing oscillating forces within the system and leading to the generation of tonal noises and vibrations. In order to minimize the level of noise, different porting geometries and vane spacing are used. This paper describes an optimization method intended to identify the best possible spacing of the vanes in the conventional 7-vanes, 9-vanes and 11-vanes oil pumps. The method integrates a Matlab routine with the modeFRONTIER software to create the required design space in order to perform a multi-objective optimization using a genetic algorithm. Results of this optimization method are discussed and a design guideline for the VDOP vane spacing is disclosed.
Viewing 181 to 210 of 7824

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