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Technical Paper
2014-09-16
Janice Meraglia, Mitchell Miller
As part of a comprehensive counterfeit mitigation effort, the Defense Logistics Agency (DLA) has created a program of four initiatives including the requirement of SigNature DNA marking on microcircuits. The Agency’s efforts began prior to the National Defense Authorization Act of Fiscal Year 2012, Section 818. Also, in the April 26, 2013 memo from Under Secretary Frank Kendall, the Office of Secretary of Defense is clearly focused on “prevention and early warning,” as the “primary” defense against counterfeits. SigNature DNA marking is within the spirit and guidance set forth by both DLA and OSD. Section 818 compels government action and creates real liability for contractors. Among other provisions, Section 818 requires the government and contractors to establish “…policies and procedures to eliminate counterfeit electronic parts from the defense supply chain” and “…mechanisms to enable traceability of parts.” SigNature® DNA provides per part forensic traceability and can be implemented as part of a comprehensive inventory management system.
Article
2014-07-23
In development of an advanced test engine to demonstrate fuel-saving and emissions-reducing technologies, the EPA is using ANSYS FORTÉ CFD software, giving its engineers the ability to quickly and inexpensively make multiple design iterations.
Article
2014-07-16
Ram’s official move to adopt the SAE J2807 towing standard for validating all three (1500, 2500, and 3500) of its pickup weight classes raises the competitive bar for the industry's other pickup players. Meanwhile, Ford has engineered its latest F-450 with half the GCVW capability of a Class-8 tractor-trailer.
Article
2014-07-15
Opel recently broke ground on a €210 million expansion of its Rüsselsheim International Technical Development center (ITDC) that will be used to develop and test engines. The 36,000-m² (400,000-ft²) expansion will be completed in 2017.
Article
2014-07-15
Northrop Grumman Corp. broke ground on a new $20 million Maryland Space Assembly and Test (M-SAT) facility on its Baltimore campus adjacent to Baltimore Washington International Thurgood Marshall Airport.
Article
2014-07-15
VPT Inc. has added a comprehensive radiation laboratory and test services facility to its Chelmsford, MA, facility. The 5000-ft² VPT Rad facility, which will serve the radiation and related test needs of aerospace electronics manufacturers, provides specialized environments and equipment for evaluating electronics used in applications where ionizing radiation can degrade device performance.
Magazine
2014-07-10
Off-highway engines advance beyond Tier 4 With Tier 4 Final/Stage IV needs met, engine OEMs direct their focus and competitive energies toward optimizing competitive solutions. At the same time, they need to keep a weather eye out for future regulations, which many expect. Autonomous vehicle challenges span many fields Many of the challenges faced by military and commercial design teams are similar. Racket busters With a quiet cab at the top of many tractor buyers' wish lists, agricultural equipment manufacturers are pursuing every opportunity possible to shed decibels.
Article
2014-07-07
Recently, with increased vehicle safety requirements, vehicle manufacturers are installing cutting-edge testing equipment in their own crash test facilities.Chrysler Group LLC partnered with Messring Systembau GmbH to upgrade Chelsea Proving Grounds, the central testing facility in Chelsea, MI.
Standard
2014-07-01
This SAE Aerospace Information Report (AIR) provides Nuclear, Biological and Chemical (NBC) protection considerations for environmental control system (ECS) design. It is intended to familiarize the ECS designer with the subject in order to know what information will be required to do an ECS design where NBC protection is a requirement. This is not intended to be a thorough discussion of NBC protection. Such a document would be large and would be classified. Topics of NBC protection that are more pertinent to the ECS designer are discussed in more detail. Those of peripheral interest, but of which the ECS designer should be aware are briefly discussed. Only radiological aspects of nuclear blast are discussed. The term CBR (Chemical, Biological, and Radiological) has been used to contrast with NBC to indicate that only the radiological aspects of a nuclear blast are being discussed. This is actually a more accurate term to describe the subject of this paper, but NBC has become more widely used in the aircraft industry.
Article
2014-06-30
Camber Corp. signed an agreement with Texas A&M–Corpus Christi (TAMUCC) to be the lead systems and business integrator for the Lone Star Unmanned Aircraft Systems Center (LSUASC) Test Site. The LSUASC is one of six unmanned aircraft systems (UAS) test sites identified by the FAA.
Technical Paper
2014-06-30
Bryce Gardner, Tiago Macarios
Abstract Speech transmissibility is a critical factor in the design of public address systems for passenger cabins in trains, aircraft and coaches. Speech transmissibility is primarily affected by the direct field, early low order reflections, and late reflections (reverberation) of the source. The direct and low order reflections are affected by the relative location of speakers and seats as well as the acoustic properties of the reflecting walls. To properly capture these early reflections, measures of speech transmissibility typically require time domain information. However, another important factor for speech transmissibility is background noise due to broadband exterior sources such as a flow noise sources. The background noise is typically modeled with broadband steady state assumptions such as in statistical energy analysis (SEA). This works presents an efficient method for predicting speech transmissiblity by combining ray tracing with SEA. In this method, the direct field and low order reflections are modelled using raytracing, while the reverberant field and background noise are modelled using SEA.
Technical Paper
2014-06-30
Yong Che
Abstract As motor assembly of Battery Electric Vehicle (BEV) replaces engine system of Internal Combustion Engine (ICE) vehicle, interior structure-borne noise induced by road random excitation becomes more prominent under middle and high speed. The research is focused on central driving type BEV. In order to improve interior noise in middle and low frequency range, dynamic load of BEV body must be identified. Consequently the structural noise induced by road excitation is conducted. The limitations of common identification method for dynamic body load are analyzed. The applied several identification methods are proposed for deterministic dynamic load such as engine or motor. Random dynamic load generated by road excitation is different from deterministic dynamic load. The deterministic load identification method cannot be applied to the random load directly. An identification method of dynamic body load for BEV is presented based on power spectrum decomposition. The procedure of BEV body load identification is described.
Technical Paper
2014-06-30
Hiromichi Tsuji, Satoshi Takabayashi, Eiji Takahashi, Hitoshi Murakami, Shinichi Maruyama
A finite element (FE) model of vibro-acoustic coupling analysis, such as a vehicle noise and vibration, is utilized for the improvement of the performance in the vehicle development phase. However, the accuracy of the analysis is not enough for substituting a prototype phase with a digital phase in the product development phases. Therefore, conducting the experiments with the prototype vehicle or the existed production vehicle is still very important for the performance evaluation and the model validation. The vehicle noise transfer function of the road noise performance cannot be evaluated with the existed excitation equipment, such as the 3 or 6 directional electromagnetic shaker. Therefore, this paper proposes new experimental method to measure the road noise vehicle transfer function. This method is based on the reciprocity between the tire contact patch and the driver's ear location. The reaction force sensor of the tire contact patch is newly developed for the reciprocal loud speaker excitation at the passenger ear location.
Technical Paper
2014-06-30
Barbara Neuhierl, David Schroeck, Sivapalan Senthooran, Philippe Moron
Abstract This paper presents an approach to numerically simulate greenhouse windnoise. The term “greenhouse windnoise” here describes the sound transferred to the interior through the glass panels of a series vehicle. Different panels, e.g. the windshield or sideglass, are contributing to the overall noise level. Attached parts as mirrors or wipers are affecting the flow around the vehicle and thus the pressure fluctuations which are acting as loads onto the panels. Especially the wiper influence and the effect of different wiper positions onto the windshield contribution is examined and set in context with the overall noise levels and other contributors. In addition, the effect of different flow yaw angles on the windnoise level in general and the wiper contributions in particular are demonstrated. As computational aeroacoustics requires accurate, highly resolved simulation of transient and compressible flow, a Lattice-Boltzmann approach is used. The noise transmission through the interior is then modeled by statistical energy analysis (SEA), representing the vehicle cabin and the panels excited by the flow.
Technical Paper
2014-06-30
Denis Blanchet, Anton Golota, Nicolas Zerbib, Lassen Mebarek
Abstract Recent developments in the prediction of the contribution of wind noise to the interior SPL have opened a realm of new possibilities in terms of i) how the convective and acoustic sources terms can be identified, ii) how the interaction between the source terms and the side glass can be described and finally iii) how the transfer path from the sources to the interior of the vehicle can be modelled. This paper discusses in detail these three aspects of wind noise simulation and recommends appropriate methods to deliver required results at the right time based on i) simulation and experimental data availability, ii) design stage and iii) time available to deliver these results. Several simulation methods are used to represent the physical phenomena involved such as CFD, FEM, BEM, FE/SEA Coupled and SEA. Furthermore, a 1D and 2D wavenumber transformation is used to extract key parameters such as the convective and the acoustic component of the turbulent flow from CFD and/or experimental data whenever available.
Technical Paper
2014-06-30
Xiaohong Kuang, Jian Pang, Haiyan Zhang, Liang Yang, Jiang-hua FU
Abstract The paper describes the identification and control methods of turbocharger surge noise. Some parameters, such as temperature, flow quantity, pressure, vibration, turbocharger rpm and noise, are provided to identify surge noise. The advantages and disadvantages for each parameter are analyzed. The paper identifies that some special vehicle interior noise is contributed by turbocharger surge noise by using correlation analysis of the turbocharger inlet temperature, outlet pressure and vehicle internal noise. Spectral filtration analysis shows that the surge noise frequency components are above 1000Hz with wide frequency band. Quarter wave tuner's effective frequency range is found to be consistent with the surge noise frequency band. A panfluter-resonator which is a combination of several special quarter wave tuners is invented to diminish the wide band high frequency noise. After the panfluter-resonator is installed on a turbocharger system, the vehicle interior surge noise is significantly reduced.
Technical Paper
2014-06-30
Alessandro Zanon, Michele De Gennaro, Helmut Kuehnelt, Domenico Caridi, Daniel Langmayr
Abstract In hybrid and electrical vehicles new challenges in meeting the drivers' expectation with regards to acoustic comfort arise. The absence of the internal combustion engine noise enhances the passengers' perception of other noise sources, such as the Heating, Ventilation and Air-Conditioning (HVAC) system. Therefore efficient and reliable numerical models able to predict flow-induced broadband noise have become a major research topic in automotive industry. In this framework, the Zonal LES coupled with the Ffowcs Williams-Hawkings (FWH) acoustic analogy are capable to simulate broadband noise from low speed axial fan. As demonstrated in previous works from the authors, this approach is able to cope with the complexity of the physical phenomena involved (i.e. turbulent noise generation, laminar-to-turbulent transition, etc.), even though the numerical model requires a careful setup of the mesh topology, boundary conditions and simulation parameters. The aim of this article is to provide the scientific community with the latest developments of our research work on numerical modelling of broadband noise from axial fans, focusing on the performance of two different mesh topologies to locate and estimate the noise sources.
Technical Paper
2014-06-30
Georg Eisele, Klaus Wolff, Jannis Hoppermanns, Peter Genender
Abstract Transfer path analysis is a powerful tool to support the vehicle NVH development. On the one hand it is a fast method to gain an overview of the complex interplay in the vehicle noise generation process. On the other hand it can be used to identify critical noise paths and vehicle components responsible for specific noise phenomena. FEV has developed several tools, which are adapted to the considered noise phenomena: Powertrain induced interior noise and vibration is analyzed by VINS (Vehicle Interior Noise Simulation), which allows the deduction of improvement measures fast enough for application in the accelerated vehicle development process. Further on vehicle/powertrain combinations not realized in hardware can be evaluated by virtual installation of the powertrain in the vehicle, which is especially interesting in the context of engine downsizing from four to three or six to four cylinders. Road induced interior noise is investigated by “Chassis-VINS” or “Fast-VINS”, depending on the required level of detailing and project timing.
Technical Paper
2014-06-30
Dirk Mayer, Jonathan Militzer, Thilo Bein
Abstract The automotive industry is aiming at both reducing the weight of the vehicles while improving a high level of comfort. This causes contradicting requirements for the systems used for noise and vibration control. Thus, active systems are investigated which may enhance the performance of passive noise and vibration control in vehicles without adding excessive weight. In this paper, basic principles for the implementations of those systems with a focus on the control systems are reviewed. Examples from implementations in automotive applications are presented, including control of engine vibrations, structure borne noise transmitted from the road into the passenger compartment and low-frequency chassis vibrations. Based on adaptive filter systems already widely used in active noise control adaptation of the control algorithms to the specific application scenarios are discussed. This includes different configurations for feedforward and feedback control, single- and multichannel control systems and the utilization of different actuator concepts like active mounts, inertial mass actuators and active tuned absorbers, as well as different control sensors like accelerometers and microphones.
Technical Paper
2014-06-30
Gregor Müller, Gottfried Grabner, Michael Wiesenegger, Jörg Jany
The optimal styling of the exterior surface of a vehicle and its suspension system have a direct impact on interior wind noise. Both are determined in early project phases when no hardware prototype is available. Turbulent flows produce both external pressure fluctuations at the vehicle shell, known as hydrodynamic excitation, and sound waves, known as acoustic excitation. Hydrodynamic and acoustic sound sources are evaluated separately and relative to each other in the frequency domain in order to perform evaluations of different body shapes. The technical aim of the presented work is to investigate how acoustic quantities measured at the outside of a vehicle can be used to assess the influence of styling modifications to interior sound pressure level. The methodology is required to be capable of being integrated into the serial development process and therefore be quickly applicable. MAGNA STEYR Engineering has conducted extensive research to develop a method to ensure the best option is selected in the early project stages.
Technical Paper
2014-06-30
Hiromichi Tsuji, Kimihiko Nakano PhD
This paper presents new technique to estimate the projected operational forces, which is the operational forces with respect to the evaluation location, at the connections of the separated passive substructures with reciprocity. Since the transfer path analysis (TPA) is conducted with respect to the evaluation location, the forces for the substructures are, therefore, also required only to estimate the projected operational forces. In order to estimate the forces, the projected inertance matrix, which is the projection of the inertance matrix onto the subspace with respect to the evaluation location, is estimated without measuring it directly. The acceleration responses at the connections of the passive substructure are measured by the excitation at the evaluation location with the reciprocity. The technique decomposes the acceleration responses into the output and input element vectors on the subspace. With those vectors, the projected inertance matrix is constructed. The projected operational forces at the passive substructure can be estimated by the operational accelerations pre-multiplied by the inverted projected inertance matrix.
Technical Paper
2014-06-30
Farokh Kavarana, Kin Yu, Tyler Robbins, John DeYoung
Abstract The advantages of hydraulic mounts over conventional elastomeric mounts for NVH refinement are well known, particularly in the area of engine and suspension mounts. Recently, hydraulic mounts have been successfully employed as body mounts between the frame and cab, principally to control freeway hop in pickup trucks. Due to their ability to provide increased damping at small displacements, hydraulic body mounts also have good potential to reduce smooth road shake. This paper documents the reduction in smooth road shake performance of a full size pickup truck. Hydraulic body mounts tuned to the frequency of the smooth road shake sensitivity area were added to the rearmost cab mount location. Both tire-wheel balance and uniformity were set to the highest production level specification allowed and the effect of hydraulic cab mount was measured experimentally during smooth road driving at medium to high speeds. Hydraulic body mounts were found to be successful in reducing smooth road floor shake by up to 6 dB, thereby considerably refining the vehicle vibration due to first order tire-wheel input forces.
Technical Paper
2014-06-30
Kasper Steen Andersen, Fuyang Liu
The tailpipe noise from an aftertreatment system must comply with legislation and meet customer expectations. The approach to capture the influence of complicated geometries and the ceramic substrates included in full aftertreatment systems (ATS) is implemented by coupling the 1D analytical solution of the substrates with the 3D FEM solution. The simulations are verified with measurements in a flow acoustic test rig.
Technical Paper
2014-06-30
Augusto Medeiros, Tiago Macarios, Gregorio Azevedo, Bryce Gardner
Abstract Transmission loss (TL) is a common metric for the comparison of the acoustic performance of mufflers. Muffler TL can be computed from a Boundary Element Method (BEM) model. Perforated tube elements are commonly used in automotive muffler applications. These can be modeled with a detailed BEM model that includes each individual hole in the perforated tube. The main drawback with such a straightforward BEM approach is that the discretionary of the perforated surfaces can result in computationally expensive models. The current work uses an approach that is a more computationally-efficient, yet, precise way of modeling complex mufflers that contain perforated surfaces with BEM. In this approach, instead of explicitly modeling the perforations explicitly they are taken into account as equivalent transfer impedances. There are several models in the literature that can be used to develop the transfer impedance model of the perforated surface. This paper investigates how these models can be used in a BEM prediction and also how one needs to be careful in selecting the cases used to evaluate the models.
Technical Paper
2014-06-30
Dennis Bönnen, Djahanchah Bamdad-Soufi, Hannes Steinkilberg, Kwin Abram
Abstract In recent years the automotive industry has been using an increasing number of high powered engines with fewer cylinders, with the goal to reduce weight and fuel consumption and hence to achieve lower CO2 emissions. In the following paper, an overview about the currently existing methods and products within the exhaust development is given which follow automotive lightweight trend. Continuous innovations in new materials, structural design and manufacturing process as well as mastering the integration of the components and modules within the system with a thorough understanding and optimization of the system behavior is enabling the reduction of weight in exhaust system. Another possibility to reduce the weight is the use of additional components such as valves. In the following, a discussion about the different types of valves is presented. These valves can be implemented within the exhaust system in order to bring a constraint in the system and consequently additional acoustic damping.
Technical Paper
2014-06-30
Antti Hynninen, Mats Abom
Abstract The after treatment devices (ATD) used in internal combustion engine (IC-engine) exhaust systems are mainly designed with emphasis on emission control, i.e. chemical efficiency, while paying less attention to the acoustic performance. In automotive applications, the duct diameters are so small that studying the acoustic wave propagation only in the plane wave frequency range is usually sufficient. In the case of medium speed IC-engines, used for example in power plants and ships, the three dimensional acoustic phenomena must also be taken into account. The main elements of the medium speed IC-engine ATD are the selective catalytic reducer (SCR) and oxidation catalyst (OC), which are based on a large amount of coated channels, i.e. the substrates. The number and type of the substrates depends not only on the regional environment legislations but also on the engine type. In this study the acoustic attenuation of a medium speed IC-engine ATD is simulated and the results are compared with measurements.
Technical Paper
2014-06-30
Sameh AFFI
Abstract Many car manufacturers are introducing Stop & Start systems based on conventional ring gear starter, which represents an economical solution without heavy modifications of their existent architectures especially if they consider hybrid technology. However, this solution is unfortunately not very satisfying from NVH point of view. Indeed, customers usually accept a noisy and quite long engine restart when it happens only one time at the kick-off. However, for hybrid vehicles, an inaudible and quick restart is required because it happens without any drivers' demand and thus it may disturb them. In this paper, we focused on NVH analysis of engine restart sequence with conventional ring gear starter. Some solutions were tested in order to optimize restart duration and noise level. Permanently engaged starter and high power starter are two simple and economical solutions that allow reducing significantly both starter noise level and engine restart duration, which makes this technology acceptable for hybrid vehicles.
Technical Paper
2014-06-30
Ennes Sarradj, Thomas Geyer, Christoph Jobusch, Sebastian Kießling, Alexander Neefe
Abstract The development of energy-efficient and lightweight vehicles is a major challenge for researchers and engineers in the automotive industry, with one solution being the use of micro gas turbines in serial hybrid vehicles. Among other advantages, the use of a micro gas turbine instead of a reciprocating engine enables a high reliability and low emissions. What makes the concept of using a gas turbine even more interesting are its special NVH characteristics, which are quite different from those of a reciprocating engine. Besides the fact that a gas turbine in general produces less noise and vibration than a diesel engine of the same power, the characteristic noise spectrum is also very different. In this paper, the noise characteristics of a micro gas turbine are compared to those typical for a common reciprocating engine and the sources of the noise are considered. The data that form the basis for these analyses were obtained using measurements on a 70 kW micro gas turbine that is designed to be used in a serial hybrid concept for buses.
Technical Paper
2014-06-30
Barry M. James, Andreas Hofmann
Abstract The noise performance of fully electric vehicles is essential to ensure that they gain market acceptance. This can be a challenge for several reasons. Firstly, there is no masking from the internal combustion engine. Next, there is pressure to move to cost-efficient motor designs such as Switched Reluctance Motors, which have worse vibro-acoustic behaviour than their Permanent Magnet counterparts. Finally, power-dense, higher speed motors run closer fundamental frequency to the structural resonances of the system [1]. Experience has shown that this challenge is frequently not met. Reputable suppliers have designed and developed their “quiet” subsystems to state of the art levels, only to discover that the assembled E-powertrain is unacceptably noisy. The paper describes the process and arising results for the noise simulation of the complete powertrain. The dynamic properties are efficiently modelled as a complete system and subjected to motor excitation (torque ripple, electro-magnetic forces and rotor imbalance).
Technical Paper
2014-06-30
Michael Klanner, Mathias Mair, Franz Diwoky, Oszkar Biro, Katrin Ellermann
Abstract The noise vibration and harshness (NVH) simulation of electric machines becomes increasingly important due to the use of electric machines in vehicles. This paper describes a method to reduce the calculation time and required memory of the finite element NVH simulation of electrical machines. The stator of a synchronous electrical machine is modeled as a two-dimensional problem to reduce investigation effort. The electromagnetic forces acting on the stator are determined by FE-simulation in advance. Since these forces need to be transferred from the electromagnetic model to the structural model, a coupling algorithm is necessary. In order to reduce the number of nodes, which are involved in the coupling between the electromagnetic and structural model, multipoint constraints (MPC) are used to connect several coupling nodes to one new coupling node. For the definition of the new coupling nodes, the acting load is analyzed with a 2D-FFT. After the coupling with MPCs, forces are only acting on the newly defined coupling nodes.
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