Huber P.,PROSE AG |
Nelain B.,VibraTec |
Muller R.,SBB AG
Notes on Numerical Fluid Mechanics and Multidisciplinary Design | Year: 2015
The goal of the EU project RIVAS (Railway Induced VibrationAbatement Solutions) is to take ground-borne vibration mitigation on open tracks an essential step forward. In this context, measures to be taken on the rolling stock are investigated in Work Package 5 (WP5). The influence of rolling stock was tested in comprehensive ground vibration measurements of regular trains carried out in the SBB railway network. The vibration analyses were correlated with vehicle-specific data and out-of-roundness measurements. The analyses show that of all railway vehicle parameters, wheel condition and unsprung mass have the major influence on vibration emissions. These analyses result in vibration mitigation measures on the rolling stock with the goal of sustainably improving wheel condition and reducing unsprung mass. These measures have the potential of considerably reducing vibrations and will be further developed. © Springer-Verlag Berlin Heidelberg 2015.
Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: AAT-2007-1.4.01 | Award Amount: 39.99M | Year: 2008
Since the publication of the ACARE goals, the commercial and political pressure to reduce CO2 has increased considerably. DREAM is the response of the aero-engine community to this pressure. The first major DREAM objective is to design, integrate and validate new engine concepts based on open rotor contra-rotating architectures to reduce fuel consumption and CO2 emissions 7% beyond the ACARE 2020 objectives. Open rotors are noisier than equivalent high bypass ratio turbofan engines, therefore it is necessary to provide solutions that will meet noise ICAO certification standards. The second major DREAM objective is a 3dB noise emission reduction per operation point for the engine alone compared to the Year 2000 engine reference. These breakthroughs will be achieved by designing and rig testing: Innovative engine concepts a geared and a direct drive contra-rotating open rotor (unducted propulsion system) Enabling architectures with novel active and passive engine systems to reduce vibrations These technologies will support the development of future open rotor engines but also more traditional ducted turbofan engines. DREAM will also develop specifications for alternative fuels for aero-engines and then characterise, assess and test several potential fuels. This will be followed by a demonstration that the selected fuels can be used in aero-engines. The DREAM technologies will then be integrated and the engine concepts together with alternative fuels usage assessed through an enhanced version of the TERA tool developed in VITAL and NEWAC. DREAM is led by Rolls-Royce and is made of 47 partners from 13 countries, providing the best expertise and capability from the EU aeronautics industry and Russia. DREAM will mature technologies that offer the potential to go beyond the ACARE objectives for SFC, achieving a TRL of 4-5. These technologies are candidates to be brought to a higher TRL level within the scope of the CLEAN SKY JTI.
Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: SST.2010.1.1-3. | Award Amount: 8.16M | Year: 2011
Ground vibration, effected by rail services, is an important environmental concern, affecting European citizens nearby any rail infrastructure. Surveys show that many Europeans are subjected to annoying levels of feelable vibration and vibration-induced noise. Although solutions are available for track in tunnels, tracks at grade are a much more extensive problem even for vibration-induced noise. However, solutions for tracks at grade are lacking: for some problems currently no feasible solutions at reasonable cost are available. A group of railway operators, infrastructure managers, infrastructure and rolling stock manufacturers, and construction companies, end users of vibration mitigation technology, have gathered, to propose a major project for Railway Induced Vibration Abatement Solutions (RIVAS). They aim at providing tools and methods to reduce vibration below the threshold of annoynace and induced noise below background levels by 2013. The group includes the expertise of research organisations and universities with specialist laboratory and theoretical modelling facilities. The issues are treated in a holistic way with the focus on reducing the annoyance to lineside residents. The project examines all vibration effects and aspects of the system: vehicle, track, propagation, freight and high-speed rail services. WP1 establishes the test procedures to monitor and control the performance of vibration mitigation measures under realistic conditions WP2 develops and evaluates mitigation measures based on reducing the excitation of vibration at the vehicletrack interface by improved maintenance WP3 develops and evaluates mitigation measures for ballasted and slab tracks WP4 will develop and evaluate mitigation measures based on sub-grade improvement and ground barriers within the railway infrastructure WP5 addresses the impact of the vehicle Each of the solutions is to be validated with field tests on the major European rail networks represented in RIVAS
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: SST.2011.2.5-1. | Award Amount: 3.21M | Year: 2011
ACOUTRAIN will simplify and improve the acoustic certification process of new rolling stock, in particular relating to the TSI Noise. Today the need of conformity assessment for a new vehicle according to the TSI Noise represents a significant element of both cost and time to market due to the need to carry out expensive and time consuming tests. The goal of the proposed project is to speed up the product authorisation by introducing some elements of virtual testing while retaining the same degree of reliability and accuracy. A successful simplification of the TSI conformity assessment process would result in a strengthening of the competitiveness of the European railway sector. The risk of not developing such a simplification would be that the expense of excessive certification of new products could hamper the introduction of new innovations. The major outcome of the ACOUTRAIN project will be a new certification process including some elements of virtual testing. This will be ready for inclusion in the next full revision of the TSI Noise, planned in 2013. The R&D work program will be implemented with the following objectives: WP1- establishment of procedures for a virtual certification of acoustic performances of freight and passenger trains; WP2 -an improvement and harmonization of the rolling noise characterization process; WP3 -establishment of methodologies to measure other noises sources; WP4 - a methodology to validate global tools for pass-by noise and standstill noise predictions so that they can be used as part of future certification; and WP5 - a validation of the procedure range for the virtual noise certification. A significant part of the project is dedicated to the relationship with the Notify Bodies and Authorities to ensure that the objectives of the project are well connected with their expectations.
Agency: European Commission | Branch: FP7 | Program: BSG-SME | Phase: SME-2012-1 | Award Amount: 1.51M | Year: 2012
Recent trends in European housing and demographics have had a significant effect on the European domestic appliances sector, in particular for laundry. A growth in single occupancy, an increase in multi-dwelling buildings (flats) and a fall in household floor space have all driven an increase in the purchase of combined washer-dryers, growing at 9% p.a. However, washer-dryers are inefficient, using as much as 50% more energy to wash and dry a load than separate systems. This is a concern both for energy consumption and cost for the user - estimated 15 million washer-dryers consume 18 TWh of electricity worth 300m and indirectly emit 10,000 tonnes of CO2 each year. As well as energy efficiency, washer-dryers also have practical limitations. Due to the small drum size of the machine compared to a dedicated tumble dryer, it is not possible to dry a full wash load in one go, adding to cost and significantly reducing convenience. LoWash will address these issues by creating a highly energy-efficient machine capable drying a complete wash load without user intervention. It will achieve this by combing an innovative hydraulic load balancing drum with a unique passive/active heat pump drying chain to create a washer-dryer capable of washing and drying a complete 7kg load without removing any of it from the machine. It will do this using <50% of the energy required by current washer dryers. Realising this vision would provide a 34m market opportunity to our consortium for washer-dryers. The technology can also be applied to standalone washing machines and tumble driers, which would more than double the market potential. In the process, LoWash will save 16 GWh of electricity over 5 years.
Thivant M.,Vibratec |
Andersson P.B.U.,Chalmers University of Technology |
Guyader J.-L.,INSA Lyon
Acta Acustica united with Acustica | Year: 2011
This paper proposes the intensity potential approach for prediction of high-frequency sound power radiation.The approach is based on the Helmholtz decomposition of the vector field of time-averaged sound intensity into its irrotational and rotational components. The local power balance in a lossless medium is expressed in terms of the irrotational component only, and results in the Poisson equation for a scalar intensity potential of this component only. The approach gives an exact expression for the sound power through any closed surface in terms of the irrotational component, provided that the boundary conditions are correct. The approach is evaluated by exploring the two intensity components in three canonical examples, and by comparison to measured data with special focus on directivity aspects. It is concluded that the intensity potential approach is relevant, in particular for high-frequency sound fields from multiple sources that are uncorrelated and broadbanded. However, the intensity is generally overestimated in the shadow zones and underestimated in the directly exposed regions. Further, peaks in narrow frequency bands associated with interference of waves are ignored. © S. Hirzel Verlag.
Nielsen J.C.O.,Chalmers University of Technology |
Mirza A.,Bombardier |
Cervello S.,Lucchini RS S.p.A |
Huber P.,PROSE AG |
And 3 more authors.
International Journal of Rail Transportation | Year: 2015
Wheel out-of-roundness (OOR) and unsprung mass are key railway vehicle parameters influencing the dynamic wheel‒rail contact loads and inducing ground-borne vibration. For a given combination of vehicle speed, track/soil conditions and wheel/rail irregularity level, reducing the unsprung mass leads to a reduction in contact loads and vibration at frequencies above the resonance of the wheelset on the primary suspension. Guidelines for reducing unsprung mass are presented, including alternative designs for the wheelset and the suspension of the mechanical drive system. For locomotives and powered bogies, the potential for reduced vibration level is 2-4 dB by improving the drive suspension design. Based on an extensive field measurement campaign, where the influence of several different types of vehicle on vibration level was measured, it was found that the maximum vibration levels were generated by freight locomotives. For several freight locomotives of the same type, a high statistical variance (up to 20 dB) in measured vibration level was observed indicating a significant spread in wheel tread conditions and OOR. Early detection of out-of-round wheels and corrective wheel maintenance are important measures to reduce vibration levels. © 2015 Taylor & Francis.
Dupont J.-B.,Vibratec |
SAE Technical Papers | Year: 2012
The automotive industry has entered a phase of change due to environmental considerations. Hybrid and electric vehicles are emerging and with them the need to include these new technologies in the design process, especially in numerical simulation methods. Different types of electromagnetic excitation may occur in electric machines. In particular, Maxwell pressure is responsible for radial forces applied to electric motor stators, which can cause a deflection and possible acoustic radiation. This paper describes a complete approach to simulate the noise radiated by electric motor stators. The principle of this multiphysics method is first to calculate the excitation due to electromagnetic phenomena using an electromagnetic finite element solver. This excitation is then projected onto the structure mesh of the stator in order to calculate the dynamic response. Finally, radiated sound power is calculated with the aid of a finite element method. The calculation methodology assumes a weak coupling between the different physical levels. This 3-step procedure is applied to an automotive electric motor and the calculation is performed for a run-up, resulting in deflection shapes and in a radiated power spectrogram. The spectrogram locally has hot spots that depend on both the topological characteristics of the motor (number of poles and slots⋯) and the modal properties of the stator. The key to understanding the motor response is the analysis of the excitation in terms of frequency and spatial order and the comparison to the stator modes. Copyright © 2012 SAE International.
Cloix A.,Vibratec |
SAE Technical Papers | Year: 2016
The current paper is based on the French research program TESSA ("Transfert des Efforts des Sources Solidiennes Actives"). A specific task within TESSA project consists in the characterization of the measurements variability between several laboratories, of the blocked forces on a water pump of a heat engine. This paper focuses only on the measurements carried out at Vibratec laboratory. Two kinds of measurements have been carried out: direct measurements, using force sensors, which is the target of the inter-laboratory measurements, and an inverse method without force sensor requirements. Reproducibility and repeatability tests have been done in order to quantify the measurement variability within the same laboratory, in preparation for the inter-laboratory disparity analysis. Specific supports have been designed for each method: a rigid aluminum block for the direct method and a support dedicated to the inverse method, including a high modal density and modal damping in the frequency range of interest. The comparison of both methods shows that the inverse method is satisfying for the measurement of blocked forces on a "non-rigid" support and that it is possible to apply such methodology "in-situ", with the source in its real environment. Copyright © 2016 SAE International.
Agency: European Commission | Branch: H2020 | Program: CS2-RIA | Phase: JTI-CS2-2015-CFP02-LPA-01-05 | Award Amount: 925.10K | Year: 2016
CANOBLE aims to develop and validate innovative engineering methods and tools up to TRL5 to study, in design phase, the noise generated inside the cockpit and cabin by the external turbulent boundary layer. A unique experimental and numerical data base will be created for the benefit of the European noise community and the European aeronautic industry. A full scale mock-up of a cockpit including a cabin section will be manufactured, instrumented, and tested in a large aeroacoustics Wind Tunnel. To bypass the TBL measurement limitation, an innovative ultra-thin pressure surface array instrumentation will be developed. The array will allow for an accurate measurement thanks to a high density of pressure sensors and the possibility to analysis the acoustic and the aerodynamic contributions of the excitation using a signal separation strategy. In parallel to the test activities, a complete aero/vibro-acoustic modelling strategy will be implemented including a TBL wall-pressure fluctuations model including adverse pressure gradients with the possibility to account for detailed TBL indicators extracted from steady-state computational fluid dynamics analysis. Finally a virtual prototype will be developed, tuned and compared with the WTT results and extended to flight cruising conditions to deliver recommendations for design purpose to the Topic Manager. CANOBLE will be executed by three organisations and will last 36 months.