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2017-08-15 ...
  • August 15-16, 2017 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
Stringent requirements of reduced NOx emission limits in the US have presented engineers and technical staff with numerous challenges. Several in-cylinder technical solutions have been developed for diesel engines to meet 2010 emission standards. These technologies have been optimized and have yielded impressive engine-out results in their ability to reduce emissions to extremely low levels. However, current and state-of-the-art in-cylinder solutions have fallen short of achieving the limits imposed on diesel emissions for 2010.
2017-06-17
Journal Article
2017-01-9550
David Neihguk, M. L. Munjal, Arvind Ram, Abhinav Prasad
Abstract A production muffler of a 2.2 liter compression ignition engine is analyzed using plane wave (Transfer Matrix) method. The objective is to show the usefulness of plane wave models to analyze the acoustic performance (Transmission Loss, TL) of a compact hybrid muffler (made up of reactive and dissipative elements). The muffler consists of three chambers, two of which are acoustically short in the axial direction. The chambers are separated by an impervious baffle on the upstream side and a perforated plate on the downstream side. The first chamber is a Concentric Tube Resonator (CTR). The second chamber consists of an extended inlet and a flow reversal 180-degree curved outlet duct. The acoustic cavity in the third chamber is coupled with the second chamber through the acoustic impedances of the end plate and the perforated plate.
2017-06-05
Technical Paper
2017-01-1753
Jack Hall Riddle, Ya-Juan Bemman, Tom Frei, Sihui Wu, Ishang Padalkar
Abstract Demands for engines to operate at low-frequency firing order are increasing in the automotive market. This requirement is driven by consumer and regulatory demand for vehicles which are more efficient in the use of fuel. As a result, engine and transmission technologies have been developed which permit operation of engines with fewer cylinders at increasingly low RPM’s. The resulting low frequency exhaust noise is more difficult to attenuate than in vehicles in years past. At the same time, vehicles often have less packaging space for mufflers, when larger volume would otherwise be needed to attenuate at lower frequencies. A further challenge is the demand for increasingly refined performance sounds from the exhaust systems of premium cars despite the technical obstacles involved in even maintaining sound quality. Finally, legally permissible sound levels are decreasing in some markets. These market and regulatory demands require new solutions.
2017-06-05
Technical Paper
2017-01-1827
Michael J. Santora, Cyril Gbenga Ige, Jeff Otto, David Egolf
Abstract A muffler attached to an engine attenuates sound over a dedicated frequency range. This research involves the development of an active muffler that is keyed to the revolutions per minute (rpm) of the engine and suppresses the fundamental frequency being exhausted through the tailpipe. The active muffler consists of a tracking side-branch resonator terminated with a composite piezoelectric transducer. The use of an exponential horn as a resonating cavity and terminated with a composite piezoelectric transducer is presented. This would create Electromechanical Active Helmholtz Resonator (EMAHR) creates a notch that can be moved between 200-1000 Hz. The use of acoustical-to-mechanical, mechanical-to-electrical, and analog-to-digital transformations to develop a system model for the active muffler are presented. These transforms will be presented as two-port network parameters. The use of two-port networks to model the electroacoustic system are a defining factor in the analysis.
2017-06-05
Technical Paper
2017-01-1875
Martino Pigozzi, Flavio Faccioli, Carlo Ubertino, Davide Allegro, Daniel Zeni
Abstract Within recent years, passenger comfort has become a main focus of the automotive industry. The topic is directly connected with acoustics, since sounds and noises have a major impact on the well-being of vehicle occupants. So-called “noise control” focuses on directly optimizing acoustic comfort by implementing innovative materials or geometries for automotive components and systems. One possibility to optimize the acoustics within a vehicle is connected to the phenomenon of sloshing in Selective Catalytic Reduction (SCR) tanks. Sloshing is a noise which is generated during normal driving situations by the motion of the Diesel Exhaust Fluid (DEF) in the tank. Until now, no procedure for measuring sloshing noise in SCR tanks has been defined, and neither a specific acoustic target which the SCR tanks need to fulfil.
2017-06-05
Technical Paper
2017-01-1865
Peter Van der Linden, Frank Daenen, Masashi Komada, Hideto Ogawa
Abstract The tendency for car engines to reduce the cylinder number and increase the specific torque at low rpm has led to significantly higher levels of low frequency pulsation from the exhaust tailpipe. This is a challenge for exhaust system design, and equally for body design and vehicle integration. The low frequency panel noise contributions were identified using pressure transmissibility and operational sound pressure on the exterior. For this the body was divided into patches. For all patches the pressure transmissibility across the body panels into the interior was measured as well as the sound field over the entire surface of the vehicle body. The panel contributions, the pressure distribution and transmissibility distribution information were combined with acoustic modal analysis in the cabin, providing a better understanding of the airborne transfer.
2017-06-05
Technical Paper
2017-01-1782
Jobin Puthuparampil, Henry Pong, Pierre Sullivan
Abstract Large-scale emergency or off-grid power generation is typically achieved through diesel or natural gas generators. To meet governmental emission requirements, emission control systems (ECS) are required. In operation, effective control over the generator’s acoustic emission is also necessary, and can be accomplished within the ECS system. Plug flow mufflers are commonly used, as they provide a sufficient level of noise attenuation in a compact structure. The key design parameter is the transmission loss of the muffler, as this dictates the level of attenuation at a given frequency. This work implements an analytically decoupled solution, using multiple perforate impedance models, through the transfer matrix method (TMM) to predict the transmission loss based on the muffler geometry. An equivalent finite element model is implemented for numerical simulation. The analytical results and numerical results are then evaluated against experimental data from literature.
2017-06-05
Technical Paper
2017-01-1791
David Neihguk, Shreyas Fulkar
Abstract Parametric model of a production hybrid (made up of reactive and dissipative elements) muffler for tractor engine is developed to compute the acoustic Transmission Loss (TL). The objective is to simplify complex muffler acoustic simulations without any loss of accuracy, robustness and usability so that it is accessible to all product development engineers and designers. The parametric model is a 3D Finite Element Method (FEM) based built in COMSOL model builder which is then converted into a user-friendly application (App) using COMSOL App builder. The uniqueness of the App lies in its ability to handle not only wide range of parametric variations but also variations in the physics and boundary conditions. This enables designers to explore various design options in the early design phase without the need to have deep expertise in a specific simulation tool nor in numerical acoustic modeling.
2017-06-05
Journal Article
2017-01-1797
Adrien Mann, Raj Nair, Jaspreet Singh Gill, Brett Birschbach, Patrick Crowley
Abstract Exhaust systems including mufflers are commonly mounted on engines to reduce the firing cycle noise originating from the combustion process. However, mufflers also produce flow-induced self-noise, originating from the complex flow path throughout the muffler. As an engine prototype is not available in the early stages of a development program, it is challenging to assess the acoustic performance of the full system when only experiment is available. It is also difficult to pinpoint the design features of a muffler generating noise, as a portion of the noise is generated internally. Numerical approaches are a possible alternative. However, capturing non-linear dissipation mechanisms and thermal fluctuations of exhaust flows is challenging, while necessary to accurately predict flow noise.
2017-06-05
Technical Paper
2017-01-1789
Rafael Veloso, Robert Fairbrother, Yasser Elnemr
Abstract The acoustics of automotive intake and exhaust systems is typically modeled using linear acoustics or gas-dynamics simulation. These approaches are preferred during basic sound design in the early development stages due to their computational efficiency compared to complex 3D CFD and FEM solutions. The linear acoustic method reduces the component being modelled to an equivalent acoustic two-port transfer matrix which describes the acoustic characteristic of the muffler. Recently this method was used to create more detailed and more accurate models based on a network of 3D cells. As the typical automotive muffler includes perforated elements and sound absorptive material, this paper demonstrates the extension of the 3D linear acoustic network description of a muffler to include the aforementioned elements. The proposed method was then validated against experimental results from muffler systems with perforated elements and sound absorptive material.
2017-06-05
Technical Paper
2017-01-1795
Ahmad Abosrea, Tamer Elnady
Abstract Flow-generated noise has recently received a lot of attention within the process of designing exhaust and intake systems. Flow-generated noise can limit the amount of sound reduction a muffler can introduce inside ducts. This is more important in the modern system design where mufflers are compact and the flow speeds become higher in different sections inside the muffler. In this paper, three measurement techniques are used to measure the flow-generated noise from a duct element. The first is based on calculating the sound power levels inside a reverberation room according to ISO 3741. The radiated noise is measured from the muffler body as a source of noise, then from the tail pipe as an active one-port source. The second is based on sound power measurements inside the ducts using the active two-port theory. The third is measuring the sound pressure radiation inside an anechoic room.
2017-06-05
Technical Paper
2017-01-1793
William Seldon, Amer Shoeb, Daniel Schimmel, Jared Cromas
Abstract As regulations become increasingly stringent and customer expectations of vehicle refinement increase, the accurate control and prediction of exhaust system airborne acoustics are a critical factor in creating a vehicle that wins in the marketplace. The goal of this project was to improve the predicative accuracy of the GT-power engine and exhaust model and to update internal best practices for modeling. This paper will explore the details of an exhaust focused correlation project that was performed on a naturally aspirated spark ignition eight-cylinder engine. This paper and SAE paper “Experimental GT-POWER Correlation Techniques and Best Practices Low Frequency Acoustic Modeling of the Intake System of a Turbocharged Engine” share similar abstracts and introductions; however, they were split for readability and to keep the focus on a single a single subsystem.
2017-06-05
Technical Paper
2017-01-1798
Jiri Navratil, Warren Seeley, Peng Wang, Shriram Siravara
Abstract The ability to accurately predict exhaust system acoustics, including transmission loss (TL) and tailpipe noise, based on CAD geometry has long been a requirement of most OEM’s and Tier 1 exhaust suppliers. Correlation to measurement data has been problematic under various operating conditions, including flow. This study was undertaken to develop robust modelling technique, ensuring sensible correlation between the 1-D models and test data. Ford use Ricardo WAVE as one of their 1-D NVH tools, which was chosen for the purpose of this benchmark study. The most commonly used metrics for evaluating the acoustical performance of mufflers are insertion loss (IL), TL, and noise reduction (NR). TL is often the first step of analysis, since it represents the inherent capability of the muffler to attenuate sound if both the source and termination are assumed to be anechoic. It can also be reliably measured and numerically simulated without having to connect to an engine.
CURRENT
2017-04-28
Standard
J1287_201704
This SAE Standard establishes the test procedure, environment, and instrumentation for determining the exhaust sound pressure levels of motorcycles under stationary conditions. Since initial publication, it has been successfully applied to regulation and monitoring of sound pressure levels of off-highway vehicles, and that remains its recommended application. Users of SAE J1287 for the purpose of roadside enforcement of sound pressure levels for on-highway motorcycles have reported difficulties with its implementation in that application. In response, SAE J2825 was developed, and is recommended for measurement of exhaust sound pressure levels of stationary on-highway motorcycles. Care must be taken not to confuse stationary sound pressure levels with total motorcycle sound pressure levels. This test does not evaluate total motorcycle sound during operation. For this purpose, SAE J331 or SAE J47 is recommended.
2017-04-04
Event
This session describes the design, modeling and performance validation of cylinder heads, lubrication systems and pumps, coolant systems and pumps, intake manifolds, exhaust manifolds, and engine block structures.`
2017-04-04
Event
This session describes the design, modeling and performance validation of cylinder heads, lubrication systems and pumps, coolant systems and pumps, intake manifolds, exhaust manifolds, and engine block structures.`
2017-03-28
Technical Paper
2017-01-1333
Sasikumar P, C. Sujatha, Chinnaraj K.
Abstract In commercial vehicles, exhaust system is normally mounted on frame side members (FSM) using hanger brackets. These exhaust system hanger brackets are tested either as part of full vehicle durability testing or as a subsystem in a rig testing. During initial phases of product development cycle, the hanger brackets are validated for their durability in rig level testing using time domain signals acquired from mule vehicle. These signals are then used in uni-axial, bi-axial or tri-axial rig facilities based on their severity and the availability of test rigs. This paper depicts the simulation method employed to replicate the bi-directional rig testing through modal transient analysis. Finite Element Method (FEM) is applied for numerical analysis of exhaust system assembly using MSC/Nastran software with the inclusion of rubber isolator modeling, meshing guidelines etc. Finite Element Analysis (FEA) results are in good agreement with rig level test results.
2017-03-28
Technical Paper
2017-01-1709
Zhigang Wei, Sarat Das, Ryan Barr, Greg Rohrs, Robert Rebandt, Xiao Wu, HongTae Kang
Abstract Recent stringent government regulations on emission control and fuel economy drive the vehicles and their associated components and systems to the direction of lighter weight. However, the achieved lightweight must not be obtained by sacrificing other important performance requirements such as manufacturability, strength, durability, reliability, safety, noise, vibration and harshness (NVH). Additionally, cost is always a dominating factor in the lightweight design of automotive products. Therefore, a successful lightweight design can only be accomplished by better understanding the performance requirements, the potentials and limitations of the designed products, and by balancing many conflicting design parameters. The combined knowledge-based design optimization procedures and, inevitably, some trial-and-error design iterations are the practical approaches that should be adopted in the lightweight design for the automotive applications.
2017-03-28
Technical Paper
2017-01-0558
Lei Cui, Tianyou Wang, Kai Sun, Zhen Lu, Zhizhao Che, Yanzhe Sun
Abstract The scavenging process in two-stroke marine engines not only transports burnt gas out of the cylinder but also provides fresh air for the next cycle, thereby significantly affecting the engine performance. In order to enhance fuel-air mixing, the scavenging process usually generates swirling flow in uniflow-type scavenging engines. The scavenging stability directly determines the scavenging efficiency and even influences fuel-air mixing, combustion, and emission of the engine. In the present study, a computational fluid dynamics (CFD) analysis of the scavenging process in a steady-state scavenging flow test is conducted. A precession phenomenon is found in the high swirl model, and Proper Orthogonal Decomposition (POD) method is used to analyze the reason and the multi-scale characteristics of the precession phenomenon.
2017-03-28
Technical Paper
2017-01-0822
Jim Elkjær Bebe, Kasper Steen Andersen
Abstract The purpose of this work is to determine essential spray parameters for a specific nozzle to be integrated in computational fluid dynamics (CFD) simulations of selective catalytic reduction systems (SCR) based on the injection of urea water solution (UWS). As Dinex does not develop nozzles, but rather integrate nozzles from a variety of manufacturers, the spray data made available is of an inhomogeneous quality. This paper presents the results of a simple, partial validation and calibration of a CFD simulation performed with the commercial CFD code AVL FIRE 2014.2 using the Lagrangian discrete droplet method. The validation is based on a novel and low cost experimental setup, where the experimental method utilizes high-speed imaging to provide spray cone angle, axial spray penetration length and spray plume droplet density.
2017-03-28
Technical Paper
2017-01-1031
Xinyan Wang, Jun Ma, Hua Zhao
Abstract In this study, the effect of the intake plenum design on the scavenging process in a newly proposed 2-stroke Boosted Uniflow Scavenged Direct Injection Gasoline (BUSDIG) engine was studied in detail by three dimensional (3D) computational fluid dynamics (CFD) simulations. In the BUSDIG engine, the intake scavenge ports are integrated into the cylinder liner and their opening and closure are controlled by the movement of piston top while exhaust valves are placed in the cylinder head. In order to accommodate the optimized scavenge ports in the real engine application, the intake plenum with an inlet pipe and a scavenge chamber was designed and connected to the 12 evenly distributed scavenge ports in a single cylinder BUSDIG engine.
2017-03-28
Technical Paper
2017-01-1081
Chongzhi Zhong, Tieqiang Fu, Chunbei Dai, Taiyu Zhang, Ke Wu, Wangwen Gu
Abstract In order to study the single cavity and double cavity canister work performance, the L/D, as well as the similarities and differences among the diameter of the adsorption mouth, purge mouth and air mouth have been studied. At the same time, the work performance of ORVR canister and common canister is also studied. The results demonstrate that the similar of L/D, efficient work ability and efficient adsorption rate of the double cavity canister is better than the single cavity canister. The bigger of L/D, the stronger work ability of the canister. However, the excessive increase of the L/D is not conducive to the canister desorption, instead resulting in the increase of RARCP. The adsorption mouth diameter of common canister is generally smaller or similar to the purge mouth, while for ORVR canister the adsorption mouth diameter is bigger than the purge mouth and similar to air mouth.
2017-03-28
Technical Paper
2017-01-1083
Chawin Chantharasenawong
Abstract This study focuses on achieving a lower overall lap time at SAE Formula Student competition through a modification to the standard intake system. The lower lap time is achieved by widening the range of engine RPM which produces torque higher than 90% of the maximum value and lowering the engine RPM corresponding to the maximum torque. An intake system with ‘variable runner length’ is introduced to the 2015 racecar of KMUTT team. The values of intake lengths are determined from the wave equation with the goal of producing over 90% of the maximum torque of the baseline configuration over a range of engine RPM. Computer simulations are performed to determine the pressure at engine entry at various runner lengths. Finally, a prototype variable runner length intake system with linear motor actuators is constructed and installed on the racecar. Chassis dynamometer tests are performed to determine the engine torque for 3,000 – 10,500 RPM at all interested runner lengths.
2017-03-28
Technical Paper
2017-01-1087
Pengfei Zang, Zhe Wang, Yu Fu, Chenle Sun
Abstract The Linear Internal Combustion Engine-Linear Generator Integrated System (LICELGIS) is different from conventional crank-based engine for reducing frictional losses by eliminating the crankshaft. Thus, the LICELGIS piston stroke is not constrained geometrically and the system compression ratio is variable. During steady-state operation, the LICELGIS converts the fuel chemical energy into electric power with piston assembly reciprocating motion, which can be used as a range-extender in hybrid electric vehicles. The LICELGIS scavenging process is prerequisite and key for the system steady-state operation, which has remarkable influence on mixture gas and, eventually, on engine combustion performance. In order to achieve high scavenging performance, a LICELGIS is investigated in this paper. The LICELGIS motion characteristics and scavenging process were analyzed.
2017-03-28
Technical Paper
2017-01-1078
Walid Ashraf, Sherif Khedr, Aya Diab, Hashim Elzaabalawy
Abstract A throttle valve is one of the main components of the intake system of a vehicle and is used to control the air flow rate into the combustion chamber at different engine speeds. Consequently, it has considerable effect on the engine power and performance especially at high engine speeds. The butterfly throttle valve is more common in commercial vehicles due to its simplicity. However, the butterfly throttle plate may affect the engine performance by incurring some pumping losses at high engine speeds even with the plate at wide open throttle (WOT) position. Hence it is proposed in this research work to replace and compare the performance of a spark ignition engine butterfly throttle valve to a newly designed barrel-shaped one with regards to the induced air mass flow rate. The main benefit of the proposed barrel-shaped throttle valve is the elimination of the flow restriction at WOT and high engine speeds.
2017-03-28
Technical Paper
2017-01-1079
Suresh Kumar Kandreegula, Sayak Mukherjee, Rahul Jain, Shivdayal Prasad, Kamal Rohilla
Abstract Flex Connectors are intended for mitigating the relative movement of exhaust system components along the axis of the system arising from the thermal expansion due to intermittent engine operation. Flex connectors must not be installed in locations, where they will be subjected to destructive vibration. Hence, the stiffness of the flex connector plays an important role, while designing or selecting the right design. It consists of a multi-ply bellows combined with an inside and an outside steel braid. The liner is included to reduce the temperature of the bellows and improve flow conditions. The braid is included for mechanical protection and to limit the possible extension of the joint. It has only axial translational motion.
2017-03-28
Technical Paper
2017-01-1076
Mohammad Moetakef, Abdelkrim Zouani, Esra Demren
Abstract In this presentation, two cases of CAE simulations of oil pump-induced tonal noises are presented. The first case involves oil pump-induced whine in an I4engine during coast down. The second case addresses oil pan moan during hot idle and the effect of oil pump pick-up tube positioning inside the oil pan of an I5 engine. The investigations include several design modifications to the pump and the pick-up tube to prevent the tonal noise. Test data are also included to demonstrate the accuracy of the CAE simulation.
2017-03-28
Technical Paper
2017-01-1077
Nicolas Arnault, Nicolas Batailley, Arnaud Maria, Laurent Bechu
Abstract PSA Group, SOLVAY and SOGEFI have teamed-up to produce the first Plastic Diesel Fuel Filter fully made of recycled polyamide 66, ready for mass-production. This has been achieved by using the brand new plastic compound developed by SOLVAY Engineering Plastics. This material is 100% recycled from airbag wastes, providing a premium material able to stand demanding applications requirements supplied through circular economy, which is quite unusual in automotive industry yet. SOGEFI has used this material through its existing plastic injection process, and tested the parts on extensive bench validation tests. It confirmed that this material is fully compatible with standard injection process, and that all the tests have been passed successfully. Finally, PSA Group has driven the choice of the tested parts: DV engine 1.6l Euro6b application, homologated the material grade and evaluated the whole validation process.
2017-03-28
Technical Paper
2017-01-1311
Suman Mishra, Nagesh Gummadi, Lloyd Bozzi, Neil Vaughn, Rob Higley
Abstract Air rush noise is exhaust gas driven flow-induced noise in the frequency range of 500-6500 Hz. It is essential to understand the flow physics of exhaust gases within the mufflers in order to identify any counter measures that can attenuate this error state. This study is aimed at predicting the flow physics and air rush noise of exhaust mufflers in the aforementioned frequency range at a typical exhaust flow rate and temperature. The study is performed on two different muffler designs which show a significant air rush noise level difference when tested on the vehicle. The transient computational study was performed using DES with 2nd order spatial discretization and 2nd order implicit scheme for temporal discretization in StarCCM+. To compare with test data, a special flow test stand is designed so that all high and low frequency contents emanating from the engine are attenuated before the flow enters the test part.
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