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Viewing 1 to 30 of 6463
2016-10-24
Event
This session considers modeling (zero-D, 1D, 2D, 3D CFD) and experimental papers on: combustion chamber, systems (lubrication, cooling, fuel, EGR); components (oil pumps, coolant pump, fuel injectors, compressors, turbines, turbochargers, torque converters, gear box, fans, bearings, valves, ports, manifolds, turbine housing); heat exchangers (radiators, oil coolers); aftertreatment (SCR, DOC, DOF, exhaust gas cooling); battery cooling (HEV, EV, motor/generator) and controls (passive and active).
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
2016-01-2161
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
2016-01-2355
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.
2016-09-20
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
2016-01-1998
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
2016-01-1929
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.
2016-09-18
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.
2016-06-28
Standard
J1598_201606
This SAE Recommended Practice is applicable to all liquid-to-gas, liquid-to-liquid, gas-to-gas, and gas-to-liquid heat exchangers used in vehicle and industrial cooling systems. This document outlines the test to determine durability characteristics of the heat exchanger from vibration-induced loading.
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.
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