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2016-10-17
Technical Paper
2016-01-2161
Gangfeng Tan
Mg2Si1-xSnx thermoelectric material is eco-friendly and of high thermoelectric performance. In this research heat transfer and power generating characteristics of the automobile exhaust heat recovery system based on Mg2Si1-xSnx material were studied. Firstly, the heat transfer model for the exhaust heat recovery system was established. Then, based on primitive characteristics of Mg2Si1-xSnx material under the different Sn/Si ratio, two-phase heat transfer of coolant was adopted and the heat transfer process was analyzed. Finally, when the saturation temperature of coolant in the two-phase zone was respectively 373K and 343K, the heat transfer and power generating characteristic were analyzed for each condition.
2016-10-17
Technical Paper
2016-01-2160
Alexander Bech, Paul J. Shayler, Michael McGhee
The application of cylinder deactivation technology to small, three cylinder spark ignition engines has the potential to further improve the part load fuel economy of these downsized engines. Although the technology is well established and proven for larger multi-cylinder engines, this is not the case for the class of 1.0litre, three cylinder engines produced by several OEM’s for use in small cars. Deactivating one cylinder by leaving the intake and exhaust valves closed and cutting fuelling requires the other two cylinders to produce more work output to compensate. This changes the distribution of heat rejection to the engine structure. The resulting increases in temperature gradients within the engine structure, and transient response times for thermal adjustments following deactivation or reactivation are examples of the uncertainties which the work reported addresses.
2016-10-17
Technical Paper
2016-01-2355
Sivanesan M, Jayabalaji G
Analytical and numerical study is carried out to study the behavior of stick-slip and judder phenomenon during engaging and disengaging of the automotive clutch. For this, a four degree of freedom torsional power train lumped mass model is developed. This torsional vibration system includes engine-flywheel, clutch, gear box and vehicle drive line, which are connected to each other by shafts. Equation of motion of the system is developed and initially a stability analysis is carried out for various gradients of coefficient of friction using eigen value analysis. Later, a numerical simulation is carried out to analyze the judder and stick-slip phenomenon using commercially available mathematical tool MATLAB. It is observed that the clutch stick-slip is increased with increase in external torque and clutch pressure fluctuations.
2016-09-27
Technical Paper
2016-01-8121
Riccardo Bianchi, Addison Alexander, Andrea Vacca
Vibrations at the cabin or at the implements of construction machinery represents important drawbacks from the points of view of machine productivity, safety and operator comfort. Oscillations of these machines are particularly relevant due to the absence of shock absorbers, typical of many machines such as wheel loaders, and their use in uneven ground conditions. Several hydraulic solutions have been proposed in the past to reduce oscillations at both the cabin or at the machine boom. Particularly, cabin oscillations can be attenuated by properly counteracting the exciting oscillatory forces from the tires with motion of the boom. Many state of the art machine utilize a passive methods to implement this strategy. The present work introduces a novel active solution, based on the control of the boom actuator without involving modifications of the standard hydraulic system.
2016-09-27
Technical Paper
2016-01-8071
Igor Gritsuk, Vladimir Volkov, Yurii Gutarevych, Vasyl Mateichyk, Valeriy Verbovskiy
The article discusses the use of the combined heating system with phase-transitional thermal accumulator. The peculiarity of the presented system is that it uses thermal energy of exhaust gas, coolant and motor oil, and emissions of internal combustion engine during its operation to accumulate the thermal energy. The results of experimental studies of the combined heating system are shown. The use of the combined heating system within phase-transitional thermal accumulators is compared with the use of standard systems for vehicle engine ZMZ-66-06 (8FS 9.2 / 8) of truck GAZ-66-11. In case of using a single thermal accumulator it allows to reduce the heating time up to 22.9-79.6% for a coolant and up to 25-80.8% for motor oil. A system and methods for pre-start and after-start heating of the vehicle engine in the investigated system are developed. The structure of a mathematical model to study the engine heating system in its various options is described.
2016-09-27
Technical Paper
2016-01-8079
Zhiwei Zhang
Abstract: Hydraulic retarder is an important auxiliary braking device. Because of its large braking torque in high speed, smooth braking, low noise, long service life and small size, it is widely used on modern vehicles. Transmission fluid of traditional hydraulic retarder is cooled by engine cooling system, which is a waste of vehicle energy to discharge the exhausted heat directly. On account of the working characteristics of hydraulic retarder, this study designs a set of waste heat recovery system based on Organic Rankine Cycle(ORC). Under the premise of ensuring stable performance of hydraulic retarder, waste heat energy in transmission fluid is recycled to supplement energy requirements for cooling system. First of all, the principle model of 100:1 is established for thermal power of D300 retarder. Then through theoretical calculations, components' structural parameters of ORC are determined.
2016-09-27
Technical Paper
2016-01-8085
Yanjun Ren, Gangfeng Tan, Ruobing Zhan
The hydraulic retarder is an auxiliary braking device generally equipped on commercial vehicles. Its oil temperature changing will influence the brake performance of hydraulic retarder. The Organic Rankine Cycle (ORC) is a good means to recover exhausted heat. Moreover, it can cool oil and stably control oil temperature with the help of heat absorption related with evaporation. Comprehensively considering the power change characteristics of hydraulic retarder and the ORC heat recovery performance, the boundary conditions of ORC are determined in order to maintain the oil temperature stability. In addition, the changing rules about the flow rate of working medium and the condensing air volume are acquired. In this research, the heat-producing properties of hydraulic retarder under different conditions and the external circulating performance is firstly analyzed. According to the oil temperature impact on braking performance, the target range of temperature control is prescribed.
2016-09-27
Technical Paper
2016-01-8100
Jordan Kelleher, Nikhil Ajotikar
Piston cooling nozzles/jets play several crucial roles in the power cylinder of an internal combustion engine. Primarily, they help with the thermal management of the piston and provide lubrication to the cylinder liner and the piston’s wrist pin. In order to evaluate the oil jet characteristics from various piston cooling nozzle (PCN) designs, a quantitative and objective process was developed. The PCN characterization began with a computational fluid dynamics (CFD) turbulent model to analyze the mean oil velocity and flow distribution at the nozzle exit/tip. Subsequently, the PCN was tested on a rig for a given oil temperature and pressure. A high-speed camera captured images at 2500 frames per second to observe the evolution of the oil stream as a function of distance from the nozzle exit. An algorithm comprised of standard digital image processing techniques was created to calculate the oil jet width and density.
2016-09-20
Technical Paper
2016-01-2000
Mark Bodie, Thierry Pamphile, Jon Zumberge, Thomas Baudendistel, Michael Boyd
Cost and performance requirements are driving military and commercial systems to highly integrated, optimized systems which require more sophisticated, highly complex controls. To realize benefits of those complex controls and make confident decisions, the validation of both plant and control models becomes critical. To quickly develop controls for these systems, it is beneficial to develop plant models and determine the uncertainty of those models to predict performance and stability of the control algorithms. Validation for an air cycle machine model based on acceptance sampling and tolerance interval is presented here. The validation process described in this presentation is based on MIL-STD 3022 with emphasis on requirements settings and the testing process.
2016-09-20
Technical Paper
2016-01-1995
Patrick McCarthy, Nicholas Niedbalski, Kevin McCarthy, Eric Walters, Joshua Cory, Soumya Patnaik
As the cost and complexity of modern aircraft systems increases, emphasis has been placed on model-based design as a means for reducing development cost and optimizing performance. To facilitate this, an appropriate modeling environment is required that allows developers to rapidly explore a wider design space than can cost effectively be considered through hardware construction and testing. This wide design space can then yield solutions that are far more energy efficient than previous generation designs. In addition, non-intuitive cross-coupled subsystem behavior can also be explored to ensure integrated system stability prior to hardware fabrication and testing. In recent years, optimization of control strategies between coupled subsystems has necessitated the understanding of the integrated system dynamics.
2016-09-20
Technical Paper
2016-01-1978
Philippe Coni, Sylvain Hourlier, Xavier Servantie, Laurent Laluque, Aude Gueguen
A 3D Stereoscopic Head-Up Display (HUD) using direct projection on a transparent screen is presented. Symbol incrustation in conformity with the landscape is performed by using simulated collimation offering a large eye-box, in excess of conventional HUD. By opposition with existing 3D system, using polarizing or active glasses, not designed for a see through system, spectral glasses are used, providing both 3D image displaying and green laser attack protection.
2016-09-20
Technical Paper
2016-01-1998
Michele Trancossi, Jose Pascoa, Carlos Xisto
Environmental and economic issues related to the aeronautic transport, with particular reference to the high speed one are opening new perspectives to pulsejets and derived pulse detonation engines. Their importance relates to a very high thrust to weight ratio and very low cost of manufacturing. This papers presents a multi-chamber cooled pulsejet architecture, which has been specifically designed for reducing the vibrations induced by a single chmber and tube pulsejet architecture. After preliminary design considerations it will take into account the thermal problem of this very simple and unespansive propulsion system. It analyses the heat transfer process through the wall of the combustion chamber of a pulsejet for aeronautic propulsion. The inside wall is exposed to burning gases with an average temperature of 1200 K, which oscillates with an amplitude 500 k and a frequency of 50 hz.
2016-09-20
Technical Paper
2016-01-1999
Debabrata Pal, Frank Feng
Cooling of high current bus bars in aircraft power panels is performed by natural convection and radiation. Thermal analysis is done using Joule heating method where the heat dissipation in bus bar is computed based on current, specified resistivity, temperature coefficient of bus bar material and geometry of bus bar. In 3 phase AC application, there is additional heat dissipation due to skin effects and proximity effects. In addition, when the 3 phase AC is used to drive a motor at high frequency (1000-1400 Hz), this results in additional higher frequency harmonics, resulting in higher losses. In this paper a thermal and electrical FEA analysis is done for a bus bar system. For electrical loss model, Infolytica MAGNET is used to characterize losses in three parallel bus bars carrying AC at various frequencies. This loss analysis provided additional losses due to skin, proximity and higher frequency harmonics. Then this loss is incorporated the ICEPAK CFD thermal model.
2016-09-20
Technical Paper
2016-01-2054
Deniz Unlu, Federico Cappuzzo, Olivier Broca, Pierpaolo Borrelli
This paper presents the activities foreseen on the Finmeccanica EIS (Entry In Service) 2020 derivative aircraft performed in the frame of the FP7 European research project TOICA (Thermal Overall Integrated Concept of Aircraft). On board air systems for conventional aircrafts are fed by the bleed off-take which penalizes the amount of power available to the power turbine of jet or turboprop engines. In order to minimize such operating penalties and optimize the energy efficiency of the overall aircraft, it is of major interest to support trade-off at aircraft level including aircraft systems as early as possible in the development cycle. The study presents the Virtual Integrated Aircraft methodology and associated simulation activities relying on the system simulation platform LMS Imagine.Lab. Several aircraft configurations and ECS packs architectures are studied and the different steps of the methodology are shown up to the trade between different aircraft configurations.
2016-09-20
Technical Paper
2016-01-1994
Wei Wu, Yeong-Ren Lin, Louis Chow, Edmund Gyasi, John P. Kizito, Quinn Leland
For aircraft electromechanical actuator (EMA) cooling application, the main objectives in axial fan design are high pressure head and high efficiency over a wide operating range including speed variation 1x~3x and pressure 0.2~1atm variation. The fan is based on a thickness of 2.54 cm, 48 mm hub, 86 mm fan diameter. The purpose of this study is to characterize a fan's performance at various rotational speeds and various ambient pressures, from 0.2 atm to 1 atm. Methodology An 86-mm diameter axial fan for electromechanical actuators was designed. The blade shape was obtained by optimization design of the radial blade using CFD technique. Geometrical parameters describing the variations of the blade profile were determined by hub contour and fan’s required parameters given above. The 3,5, 7-blade configurations were compared with the optimal blade profile. A commercial brushless DC axial fan motor is chosen. The fan blades were 3-D printed and tested in a closed test loop.
2016-09-20
Technical Paper
2016-01-1997
Wei Wu, Yeong-Ren Lin, Louis Chow, Edmund Gyasi, John P. Kizito, Quinn Leland
Recently there has been increasingly research interest on aircraft electromechanical actuator (EMA) safety. One approach to prevent EMAs from overheating is to use air cooling fans. Aircraft EMA cooling fan is a critical component because an EMA failure due to overheating could lead to a catastrophic failure in aircraft. Methodology A five-blade and seven-blade dual-fan designs are proposed. Each fan has its own independent shaft running in opposite rotating directions. Fan motors are assumed to be brushless direct current (BLDC) motors. After summarizing the possible failure causes and failure modes of BLDC fans by focusing on each failure mechanism, the life expectancy of fan ball bearings based on a major failure mechanism of lubricant deterioration was calculated and compared to such information in the literature. Finally, the advantages and disadvantages of three fault-tolerant approaches are discussed.
2016-09-20
Technical Paper
2016-01-2023
Timothy Deppen, Brian Raczkowski, Marco Amrhein, Jason Wells, Eric Walters, Mark Bodie, Soumya Patnaik
Future aircraft systems are projected to have order of magnitude greater power and thermal demands, along with tighter constraints on the performance of the power and thermal management subsystems. This trend has led to the need for a fully integrated design process where power and thermal systems, and their interactions, are considered simultaneously. To support this new design paradigm, the power quality analysis framework, developed previously, has been augmented to include thermal specifications. MIL-STD-2218 defines thermal design and cooling analysis requirements for airborne electrical equipment, while MIL-STD-704 defines transient, steady-state, and frequency-domain metrics for power quality. The proposed framework augments the power quality analysis framework developed for MIL-STD-704 and others, with a mathematical interpretation of the requirements given in MIL-STD-2218.
2016-09-18
Technical Paper
2016-01-1941
Tie Wang, Xin Gao, Zhiwei Zhang
Vehicle hydraulic retarder is applied in heavy-duty trucks and buses as an auxiliary braking device. In traditional cooling system of hydraulic retarder, working fluid is introduced into heat exchanger to transfer heat to cooling liquid in circulation, whose heat is then dissipated by engine cooling system, not enabling waste heat of working fluid used effectively. In hydraulic retarder cooling system based on Rankine cycle, organic working fluid transfers heat with hydraulic retarder working fluid in Rankine cycle, and then outputs power through expansion machine. It can both reduce heat load of engine cooling system, and enhance thermal stability of hydraulic retarder while recovering and utilizing braking energy. First of all, according to the target vehicle model, hydraulic retarder cooling system model based on Rankine cycle is established.
2016-09-18
Technical Paper
2016-01-1935
Binyu Mei, Xuexun Guo, Gangfeng Tan
With the continuous increasing requirements of commercial vehicle weight and speed on highway transportation, conventional friction brake is difficult to meet the braking performance. To ensure the driving safety of the vehicle in the hilly region, eddy current retarder has been widely used due to its fast response, lower prices and convenient installation. Electric eddy current retarder breaks the vehicle through the electromagnetic force generated by the current, and converted vehicle mechanical energy into heat through magnetic field. Air cooling structure is often used in the traditional eddy current retarder and cooling performance is limited, which causes low breaking torque, thermal recession, low reliability and so on. A water jacket has been equipped outside the eddy current region in this study, and the electric eddy current retarder is cooled through the water circulating in the circuit, which prolongs its working time.
2016-09-18
Technical Paper
2016-01-1920
Deaglan O'Meachair, Stamatis Angelinas, Matthew Crumpton, Antonio Rubio Flores, Juan Garcia, Pablo Barles
Bentley Motors Ltd. has developed a Carbon Silicon Carbide (CSiC) brake system for it’s Mulsanne product, introduced at 17MY. The CSiC brake system is conceived as a performance brake system, and as such offers notable improvements in brake performance In developing the brake system, particular focus was placed on meeting the refinement levels required for a premium product, and indeed as the flagship model for Bentley Motors, NVH refinement of the brake system was of particular concern. This paper intends to discuss the technical performance of the brake system and review the NVH performance of the brakes. This paper will also demonstrate the effect of vehicle isolation on the cabin NVH, and ultimately the passenger experience, by comparing the noise and vibration content in the wheel arch with that apparent to the driver.
2016-09-18
Technical Paper
2016-01-1929
Nimrod Kapas, Ajith Jayasundera
There is an increasing interest in transient thermal simulations of automotive brake systems using CFD software. This paper presents a detailed high-fidelity simulation tool for modeling complete braking cycles including both the deceleration and the acceleration phases. During braking, this model applies the total heat input directly at the friction interface on the contacting rotor and pad surfaces. Based on the conductive heat fluxes within the surrounding parts, the solver automatically determines the division of the thermal energy flowing from the friction interface into the solid volumes of the rotor and the pad. The convective heat transfer between the surfaces of solid parts and the cooling airflow is simulated through conjugate heat transfer, and radiative heat exchange between solid surfaces is captured by using the discrete ordinates model.
2016-06-15
Technical Paper
2016-01-1814
Maxime Legros, Jean Michel Ville, Solène Moreau, Xavier Carniel, Christophe Lambourg, Guillaume Stempfel
Abstract The new requirements during the first stages of the conception of a HVAC prompt the designer to integrate the acoustic problematic increasingly upstream. The designer needs to select a coherent components’ choice in order to comply with the specifications in terms of aeraulic and acoustic performances. A tool has been created to guide the designer’s choices based on an acoustic synthesis which is a design and/or diagnosis approach used to analyze and predict the acoustic behavior of a complex system. The synthesis is developed in order to propose an approach which considers the integration effects and some interaction effects. The acoustic synthesis results are the starting point of a psycho-acoustic study providing audio samples of the prediction and indications of the HVAC acceptance by the prospective user. Also, one may compare the results of different acoustic synthesis projects to study the influence of the parameters on the acoustic prediction.
2016-06-15
Technical Paper
2016-01-1812
Saad Bennouna, Solène Moreau, Jean Michel Ville, Olivier Cheriaux
Abstract The noise radiated inside the car cabin depends on many sources such as the embedded equipments like the Heating, Ventilation and Air Conditioning (HVAC) module. An HVAC is a compact and complex system composed of several elements: blower, flaps, thermal exchangers, ducts… Air provided by an HVAC is blown by a blower passing through different components and then distributed to car cabin areas. Interactions between airflow and the HVAC fixed components generate noises that emerge in the car cabin. CEVAS project, managed by the automotive equipment manufacturer Valeo, is aiming to develop a prediction tool which will provide HVAC noise spectrum and sound quality data. The tool is based, in particular, on aeroacoustic characterization of individual elements and associations of elements.
2016-06-15
Technical Paper
2016-01-1810
Marie Escouflaire, Nicolas Zerbib, David Mas, Nicolas Papaxanthos, Saad Bennouna, Emmanuel Perrey-Debain, Boureima Ouedraogo, Solène Moreau, Jean Michel Ville
Abstract In the framework of noise reduction of HVAC (Heating, Ventilating and Air Conditioning) systems designed for cars, the present study deals with the numerical prediction of aeroacoustics phenomena encountered inside such devices for industrial purposes, i.e. with a reasonable CPU time. It is then proposed in this paper to assess the validity of the chaining, via Lighthill-Curle analogy, of a DES (Detached Eddy Simulation) resulting from the CFD code OpenFOAM (ESI Group) versus a RANS-LES (Large Eddy Simulation) and a BEM calculation resulting from the Vibro/Aeroacoustics software VA One (ESI Group) on an academic case of air passing through a rectangular diaphragm at a low Mach number. The BEM code being parallelized, the performances of DMP (Distributed Memory Processing) solution will also be assessed.
2016-06-15
Technical Paper
2016-01-1780
Francesca Ronzio, Theophane Courtois
Abstract In automotive acoustics, body NVH design is traditionally carried out without considering the acoustic trim parts. Nevertheless, the vibro-acoustic interaction of body structure and insulation trim cannot be neglected in the middle frequency range, where structure borne propagation might still be dominating and where classical statistical approaches are generally not able to represent the influence of local changes in stiffness and damping. This, together with the market requirement of lightweight and more efficient sound package solutions, is leading the CAE engineers to evaluate new design approaches dedicated to vehicle components such as dash or floor systems, for which the multi-physics interaction between damping, body stiffness and trim impedance is important.
2016-06-15
Technical Paper
2016-01-1851
Arnaud Duval, Minh Tan Hoang, Valérie Marcel, Ludovic Dejaeger
Abstract The noise treatments weight reduction strategy, which consists in combining broadband absorption and insulation acoustic properties in order to reduce the weight of barriers, depends strongly on surface to volume ratio of the absorbing layers in the reception cavity. Indeed, lightweight technologies like the now classical Absorber /Barrier /Absorber layup are extremely efficient behind the Instrument Panel of a vehicle, but most of the time disappointing when applied as floor insulator behind the carpet. This work aims at showing that a minimum of 20 mm equivalent “shoddy” standard cotton felt absorption is requested for a floor carpet insulator, in order to be able to reduce the weight of barriers. This means that a pure absorbing system that would destroy completely the insulation properties and slopes can only work, if the noise sources are extremely low in this specific area, which is seldom the case even at the rear footwells location.
2016-06-15
Technical Paper
2016-01-1853
Timo Hartmann, Gregor Tanner, Gang Xie, David J. Chappell
Abstract Car floor structures typically contain a number of smaller-scale features which make them challenging for vibro-acoustic modelling beyond the low frequency regime. The floor structure considered here consists of a thin shell floor panel connected to a number of rails through spot welds leading to an interesting multi-scale modelling problem. Structures of this type are arguably best modelled using hybrid methods, where a Statistical Energy Analysis (SEA) description of the larger thin shell regions is combined with a finite element model (FEM) for the stiffer rails. In this way the modal peaks from the stiff regions are included in the overall prediction, which a pure SEA treatment would not capture. However, in the SEA regions, spot welds, geometrically dependent features and directivity of the wave field are all omitted. In this work we present an SEA/FEM hybrid model of a car floor and discuss an alternative model for the SEA subsystem using Discrete Flow Mapping (DFM).
2016-06-15
Technical Paper
2016-01-1800
Xavier Carniel, Anne Sanon
Abstract The control of sound fields radiated by vibrating structures in a passenger compartment, (especially structures connected to different organs like the engine powertrain, the fan motor unit, seats, the steering column, electrical motors more and more, etc.) is among the functions of the automotive manufacturers. The absence of physical prototypes in the development phase systems led OEMs1 to use tests results obtained on benches following technical specifications from manufacturers. The transition "bench to vehicle" for vibro- acoustic behaviour sets many challenges that this standard intends to clear up. This standard specifies the experimental method to transpose the dynamic forces generated by the global movements of an active component between the vehicle and a test bench. The efforts are first measured on test benches and then transposed from test bench towards the vehicle. The standard is now a French standard (XP R 19-701) and is submitted to ISO process [1].
2016-06-15
Journal Article
2016-01-1808
Manfred Kaltenbacher, Andreas Hüppe, Aaron Reppenhagen, Matthias Tautz, Stefan Becker, Wolfram Kuehnel
Abstract We present a recently developed computational scheme for the numerical simulation of flow induced sound for rotating systems. Thereby, the flow is computed by scale resolving simulations using an arbitrary mesh interface scheme for connecting rotating and stationary domains. The acoustic field is modeled by a perturbation ansatz resulting in a convective wave equation based on the acoustic scalar potential and the substational time derivative of the incompressible flow pressure as a source term. We use the Finite-Element (FE) method for solving the convective wave equation and apply a Nitsche type mortaring at the interface between rotating and stationary domains. The whole scheme is applied to the numerical computation of a side channel blower.
2016-06-15
Journal Article
2016-01-1778
Gesche Fender, Steffen Marburg, Fabian Duddeck
Abstract One method to lower noise in a cabin is to position damping layers on vibrating panels, thereby reducing their radiated power. To assess the damping effect, criteria like the ERP (equivalent radiated power) are widely employed, which estimate the radiated sound power of a panel without taking into account the actual complex system. Advantageously only a part of the structure has to be modeled, but the optimal solution found on the simplified model then often fails for the complete, coupled system, especially if several variants of a cabin have to be considered. Hence, it is proposed to use the structure-only optimization for identification of a set of candidate solutions for optimal positioning of damping layers. These candidate solutions used as initial designs for the coupled investigations should be well distributed in the design space to avoid being wrongly stuck in an optimum with inferior coupled performance.
Viewing 1 to 30 of 7822