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Viewing 1 to 30 of 15998
2017-10-13
Technical Paper
2017-01-5012
Harveer Singh Pali, Shashi Prakash Dwivedi
Abstract The present work deals with the fabrication and tribological testing of an aluminium/SiC composite. Fabrication was done using two techniques; mechanical stir casting and electromagnetic stir casting. Metal matrix composite (MMC) was fabricated using aluminium as a matrix and SiC as reinforcement in varying weight percentages. The wear and frictional properties of the MMC were studied by performing dry sliding wear test using a pin-on-disc wear tester for both types of samples. Wear rate retards with the increase the percentage of reinforcement whereas it improves with the addition of normal force. At same time frictional coefficient upsurges by increasing the normal force and percentage of reinforcement. Increasing percentage of reinforcement and using electromagnetic stir casting process obtained the higher frictional coefficient and lower wear rate.
2017-10-13
Technical Paper
2017-01-5013
G. Magendran
The input shafts are conventionally developed through Hot forging route. Considering upcoming new technologies the same part was developed through cold forging route which resulting in better Mechanical properties than existing hot forging process. It has added benefit of cost as well as environmental friendly. Generally, the part like Input shaft which having gear teeth, splines etc., will be manufactured through Hot forging process due to degree of deformation, availability of press capacity, diameter variations etc., This process consumes more energy in terms of electricity for heating the bar and also creates pollution to the atmosphere. Automotive input shaft design modified to accommodate cold forging process route to develop the shaft with press capacity of 2500T which gives considerable benefit in terms of mechanical and metallurgical Properties, close dimensional tolerances, less machining time, higher material yield when compared to hot forging and metal cutting operation.
2017-10-08
Technical Paper
2017-01-2330
Leonardo Israel Farfan-Cabrera, Ezequiel Gallardo, José Pérez-González
Abstract Flouroelastomers and silicone rubbers are commonly employed in static and dynamic seals for automotive applications. In order to prevent premature failures and leakages caused by swelling and/or changes in their mechanical properties, materials for seals are selected according to their compatibility with the environment and fluids involved in the engine operation. Thus, in particular, the use of new fuels and additives in automotive engines requires the assessment of compatibility with common sealing elastomers to prevent failures. Currently, Jatropha oil is being used as a renewable source of fuel in diesel engines for electricity production, transport or agricultural mechanization in various countries. It is used either as biodiesel or as straight vegetable oil (SVO) since it has good heating power and provide exhaust gas with almost no sulfur or aromatic polycyclic compounds. However, the compatibility of elastomers with this SVO has not been investigated yet.
2017-10-08
Technical Paper
2017-01-2357
Mark Devlin, Jeffrey Guevremont, Chip Hewette, Marc Ingram, Grant Pollard, William Wyatt
Abstract Different mechanical components in a vehicle can be made from different steel alloys with various surface treatments or coatings. Lubricant technology is needed to prevent wear and control friction on all of these different surfaces. Phosphorus compounds are the key additives that are used to control wear and they do this by forming tribofilms on surfaces. It has been shown that different operating conditions (pressures and sliding conditions) can influence the formation of tribofilms formed by different anti-wear additives. The effect of surface metallurgy and morphology on tribofilm formation is described in this paper. Our results show that additive technology can form proper tribofilms on various surfaces and the right combination of additives can be found for current and future surfaces.
2017-10-08
Technical Paper
2017-01-2183
Xiangfeng Yu, Shengcheng Li, Zhishuang Ma, Wei Du, Fengxiang Huang, Weijun Huang, Beiping Jiang
Abstract A reciprocating piston expander model based on organic Rankine cycle (ORC) is built for engine waste heat recovery. The expander characterizes by variable expansion ratio through adjusting working fluid injection timing. This paper investigates the effect of working fluid evaporating pressure, expansion ratio and clearance volume on the expander performance which mainly includes output power, equivalent recovery efficiency, total output power, expander efficiency, and the weighted efficiency of the expander, weighted heat recovery efficiency of the expander. The results demonstrate that the total output power and the equivalent heat recovery efficiency increase with working fluid evaporating pressure under overall operating conditions, while the increment is negligible. The expander reaches maximum total output power up to 83.4kW under c100 engine condition and 1.1MPa working fluid evaporating pressure within the research operating conditions.
2017-10-08
Technical Paper
2017-01-2222
ZhenYang Liu, Xihui Wang
Abstract The ever increasing popularity of electric vehicles and higher requirement on safety and comfort has led heat pump air conditioning system indispensable in electric vehicle. Many studies have shown that the addition of nano particles contributes to great improvement on thermal conductivity than that of conventional refrigerants. Therefore, the application of the magnetic nanorefrigerant in heat pump air conditioning system has massive potential to heighten the heat transfer efficiency. This paper aims at studying the magnetic nanorefrigerant comprised of the magnetic nano powder Fe3O4 and refrigerant R134a. According to the relevant theoretical analyses and empirical formula, the heat transfer coefficient, density, viscosity, and other physical parameters are calculated approximately.
2017-10-08
Technical Paper
2017-01-2219
Xihui Wang
Abstract The conventional cooling fluids in vehicle engine cooling water jacket have relatively poor heat transfer performance. The key to enhance heat transfer in cooling-jacket is to research a kind of new coolants. Nanofluids have heat transfer enhancement merits. In present study, the numerical simulation on Fe3O4 nanofluid flow in cooling water jacket of Gasoline direct injection engine was performed using computational fluid dynamics ( CFD) software FLUENT. The heat transfer coefficient of nanofluids was calculated and verified by experiment. Fe3O4 nano-particles were used in mixture of water/ethylene glycol as a base fluid. The thermal performance of the nanofluid was studied, also the thermal performance of a cooling-jacket was studied with CFD technology. The simulation was performed for different volumetric concentrations of(1%,2%,5%) nanofluids at different engine speeds. The results showed that heat transfer enhanced compared to the base fluid.
2017-10-08
Technical Paper
2017-01-2406
Wu Yang, Xiuting Yin, Zhang Song Zhan, Huixian Shen, Huibin Qing, Qingqiang Zeng, Liyun Kang
Abstract This work addresses the problem of fatigue strength prediction of crankshaft fillet rolling processes to improve its accuracy. It is empirical to usually consider the effect of fillet rolling process on crankshaft fatigue performance. The fatigue performance of rolling process is mainly determined by induced compressive residual stresses, increased hardness and reduced roughness. Because the first two factors are difficult to measure the arc surface of fillet rolled cranks, it is difficult to predict the enhanced rate of crankshaft rolled performance to baseline unrolled’s. In this work a prediction method of fatigue strength for ductile cast iron crankshafts rolling process is presented. This method indirectly predicts the effect of the increased hardness on fatigue performance by the resonant bending fatigue test and modelling of crankshaft fillet rolling dynamic for the induced compressive residual stress.
2017-10-08
Technical Paper
2017-01-2379
Qian Feng, Shu Shen, Mengliang Li, Zhijun Li, Kongjian Qin, Diming Lou, Jiguang Wang, Xiyu Fang
Abstract Recent toxicological and epidemiologic studies have shown that diesel emissions have been a significant toxic air contaminant. Catalyzed DPF (CDPF) not only significantly reduces the PM mass emissions (>90%), but also further promotes carrier self-regeneration and oxidize more harmful gaseous pollutants by the catalyst coated on the carrier. However, some ultrafine particles and potentially harmful gaseous pollutants, such as VOCs species, originally emitted in the vapor-phase at high plume temperature, may penetrate through the CDPF filter. Furthermore, the components and content of catalyst coated on the CDPF could influence the physicochemical properties and toxicity intensity of those escaping ultrafine particles and gaseous pollutants. In this work, (1) we investigated the influence of precious metal content as a variable parameter on the physicochemical properties and catalytic activities of the small CDPF samples.
2017-10-08
Journal Article
2017-01-2343
Nicolas Champagne, Nicolas Obrecht, Arup Gangopadhyay, Rob Zdrodowski, Z Liu
Abstract The oil and additive industry is challenged to meet future automotive legislations aimed at reducing worldwide CO2 emissions levels. The most efficient solution used to date has been to decrease oil viscosity leading to the introduction of new SAE grades. However this solution may soon reach its limit due to potential issues related to wear with lower engine oil viscosities. In this paper, an innovative solution is proposed that combines the use of a new tailor-made polyalkylene glycol (PAG) with specific anti-wear additives. Valvetrain wear measurements using radionuclide technique demonstrates the robustness of this solution. The wear performance was also confirmed in Sequence IVA test. An extensive tribological evaluation (film formation, wear and tribofilm surface analysis) of the interactions between the base oil and the anti-wear additives lead us to propose an underlying mechanism that can explain this performance benefit.
2017-10-08
Technical Paper
2017-01-2366
Wenzheng Xia, Yi Zheng, Xiaokun He, Dongxia Yang, Huifang Shao, Joesph Remias, Joseph Roos, Yinhui Wang
Abstract Because of the increased use of gasoline direct engine (GDI) in the automobile industry, there is a significant need to control particulates from GDI engines based on emission regulations. One potential technical approach is the utilization of a gasoline particulate filter (GPF). The successful adoption of this emission control technology needs to take many aspects into consideration and requires a system approach for optimization. This study conducted research to investigate the impact of vehicle driving cycles, fuel properties and catalyst coating on the performance of GPF. It was found that driving cycle has significant impact on particulate emission. Fuel quality still plays a role in particulate emissions, and can affect the GPF performance. Catalyzed GPF is preferred for soot regeneration, especially for the case that the vehicle operation is dominated by congested city driving condition, i.e. low operating temperatures.
2017-10-05
Journal Article
2017-01-9286
David Oh, Martin Brouillette, Jean-Sebastien Plante
Abstract A vortex-stratified combustion process for hydrogen-fueled reciprocating internal combustion engines is introduced to increase the thermal efficiency by reducing the convective heat transfer losses to the surrounding walls during combustion. The process imposes a highly ordered rotational field upon the charge in a separate, transverse, cylindrically shaped combustion chamber by means of channels that connect with the main chamber enclosed by the engine cylinder and piston. Gaseous hydrogen is injected directly during the compression stroke, while air enters into the combustion chamber tangentially and preferentially along the circumference due to the Coandă effect. The two streams entrain one another and develop into a vigorous vortex by virtue of the chamber and channel geometries.
2017-10-05
Journal Article
2017-01-9287
David Oh, Martin Brouillette, Jean-Sebastien Plante
Abstract In this second of two parts, the fundamentals of convective wall heat transfer losses are elucidated in the context of the desired objective toward its reduction in a direct-injected, hydrogen-fueled internal combustion engine. A comparative, transient 2D CFD analysis evaluated at 4500 RPM between a combustion chamber design representing current practice and the here-introduced “vortex-stratified combustion” process finds an approximately 50% reduction in the peak convective flux with the latter.
2017-10-05
Journal Article
2017-01-9288
Stefania Falfari, Gian Marco Bianchi, Giacomo Micci, Augusto Della Torre, Gianluca Montenegro, Angelo Onorati, Sergio Negro
Abstract Metallic open-cell foams have proven to be valuable for many engineering applications. Their success is mainly related to mechanical strength, low density, high specific surface, good thermal exchange, low flow resistance and sound absorption properties. The present work aims to investigate three principal aspects of real foams: the geometrical characterization, the flow regime characterization, the effects of the pore size and the porosity on the pressure drop. The first aspect is very important, since the geometrical properties depend on other parameters, such as porosity, cell/pore size and specific surface. A statistical evaluation of the cell size of a foam sample is necessary to define both its geometrical characteristics and the flow pattern at a given input velocity. To this purpose, a procedure which statistically computes the number of cells and pores with a given size has been implemented in order to obtain the diameter distribution.
2017-09-30
Technical Paper
2017-01-5009
Li Fang, Henry Hu, Xueyuan Nie, Jimi Tjong, Xuezhi Zhang
Abstract In the present study, a design of experiment (DOE) technique, the Taguchi method, was used to develop as-cast high strength aluminum alloys with element additions of Si, Cu, Ni and Sr. The Taguchi method uses a special design of orthogonal arrays to study all the designed factors with a minimum of experiments at a relatively low cost. The element factors chosen for this study were Si, Cu, Ni and Sr content in the designed aluminum-based alloys. For each factor, three different levels of weight percentages were selected (Si: 6, 9, 12%, Cu: 3, 5, 7%, Ni: 0.5, 1, 1.5% and Sr: 0.01, 0.02, 0.03%). Tensile properties such as ultimate tensile strength, yield strength and elongation at failure were selected as three individual responses to evaluate the engineering performance of the designed alloys. The results of the factor response analysis were used to derive the optimal level combinations.
2017-09-29
Technical Paper
2017-01-7004
Abhirup Chakraborty, Sagar Polisetti, Jayanthan Jayaseelan, Rajesh Upadhyay
Abstract Vibrational fatigue is a metal fatigue caused by the forced vibrations which are purely random in nature. The phenomenon is predominantly important for the components/systems which are subjected to extreme vibration during its operation. In a vehicle, an engine is the main source of vibration. The vibrational fatigue, therefore, plays a key role in the deterioration of engine mounted components. Multiple test standards and methodologies are available for validating engine mounted parts of an automobile. These might not be appropriate in the case of an off- road vehicle as the vibrational exposure of engine mounted components of an off-road vehicle is entirely different. In the case of an off-road vehicle, the engine mounted components are subjected to a comparatively higher level of vibration for a longer duration of time as compared to the passenger cars.
2017-09-22
Technical Paper
2017-01-5010
H.J. Liu, X.D. Zhang
Abstract In order to research the effect of process parameters (laser power, welding speed, wire-feed speed, spot diameter) on mechanical properties of Zn-coated Steel Laser Brazing Lap Joint for vehicle, the influence of welding parameters on energy input of brazing seam cross section was theoretically analyzed, and then a great number of laser brazing experiments of 0.7mm galvanized steel was carried out. After that, the tensile strength and micro-hardness tests were also done for well-formed joints of galvanized steel formed in the laser brazing. The results show that joints with good mechanical properties and surface morphology can be formed when laser power is in the range of 2500-3200W and the other parameters keep in a specified range. Joint performance significantly reduces when the value of wire-feed speed exceeds 3.0m/min for that a wider brazing seam cross section can’t be formed.
2017-09-19
Technical Paper
2017-01-2139
Guy Fortin
Abstract This paper reviews the current knowledge on super-hydrophobic coatings (SHC). Using an ideal super-hydrophobic surface patterned with identical cylindrical flathead posts forming a square network with constant periodicity, models are proposed to explain SHC, wear and ice adherence on SHC. The models demonstrate that SHC based on Cassie-Baxter state improve the bead mobility compared to SHC based on Wenzel state and more suitable for aircraft application. Their erosion resistance can be improved by increasing the post height and the hydrophobic material thickness. Their ice adhesion reduction factor (IARF) is better but SHC based on Cassie-Baxter state have a limitation to reduce ice adherence dependence on the surface pattern and IARF of the hydrophobic material. The bead mobility is calculated from advancing and receding water contact angles (WCA).
2017-09-19
Technical Paper
2017-01-2151
Hong huang, Qingyun Zhao, Fenglei Liu, Huadong Liu
Abstract:Split-sleeve cold expansion processing was employed on the 2024-T3 aluminum alloy plate. Fatigue lives were compared according different expansion, then the relationship of fatigue life and expansion was analyzed. Residual stresses were measured with different expension,and the fatigue fractograph was analyzed by SEM. The results show that the split-sleeve cold expansion can obtain longer life compared with the non strengthened hole. The maximum fatigue life increased to 12 times with 6% expansion. When over 6% expansion, fatigue life began to decrease. The split-sleeve cold expansion can form beneficial rasidual compressive stress,and deferred the fatigue crack initiation. The fatigue fractograph shows mixed transgranular fracture.
2017-09-19
Journal Article
2017-01-2152
Sean Taklimi, Ali Ghazinezami, Kim Cluff PhD, Davood Askari
Abstract The use of nanomaterials and nanostructures have been revolutionizing the advancements of science and technology in various engineering and medical fields. As an example, Carbon Nanotubes (CNTs) have been extensively used for the improvement of mechanical, thermal, electrical, magnetic, and deteriorative properties of traditional composite materials for applications in high-performance structures. The exceptional materials properties of CNTs (i.e., mechanical, magnetic, thermal, and electrical) have introduced them as promising candidates for reinforcement of traditional composites. Most structural configurations of CNTs provide superior material properties; however, their geometrical shapes can deliver different features and characteristics. As one of the unique geometrical configurations, helical CNTs have a great potential for improvement of mechanical, thermal, and electrical properties of polymeric resin composites.
2017-09-19
Journal Article
2017-01-2153
Patrick Land, Petros Stavroulakis, Richard Crossley, Patrick Bointon, Harvey Brookes, Jon Wright, Svetan Ratchev, David Branson
Abstract Inspection of Composite panels is vital to the assessment of their ability to be fit for purpose. Conventional methods such as X-ray CT and Ultrasonic scanning can be used, however, these are often expensive and time consuming processes. In this paper we investigate the use of off-the-shelf Non-Destructive Test, NDT, equipment utilizing Fringe projection hardware and open source software to rapidly evaluate a series of composite panels. These results are then verified using destructive analysis of the panels to prove the reliability of the rapid NDT methods for use with carbon composite panels. This process allows us to quickly identify regions of geometric intolerance or formed defects without the use of expensive sub-surface scanning systems, enabling a fast and cost effective initial part evaluation system. The focus of this testing series is on 6mm thick pre-preg carbon-epoxy composite laminates that have been laid up using AFP and formed using TRF.
2017-09-19
Technical Paper
2017-01-2148
Ho-Sung Lee
In this paper, manufacturing of launcher structural components with superplastic forming (SPF) and solid state welding technologies is presented with several examples. Some of high strength aerospace alloys, like aluminum, titanium and superalloys, are known to have superplasticity so that complex shapes of aerospace components can be produced with this technology. A combination of superplastic forming and solid state welding processes produces lighter and stiffer components than one manufactured with conventional machining and welding. Solid state welding is an attractive method to weld materials without melting where mechanical properties are important since the welding interface is homogeneous without liquid phases.
2017-09-19
Journal Article
2017-01-2142
Brandon Mahoney, Jamie Marshall, Thomas Black, Dennis Moxley
The supersession of metallic alloys with lightweight, high-strength composites is popular in the aircraft industry. However, aviation electronic enclosures for large format batteries and high power conversion electronics are still primarily made of aluminum alloys. These aluminum enclosures have attractive properties regrading structural integrity for the heavy internal parts, electromagnetic interference (EMI) suppression, electrical bonding for the internal cells, and/or electronics and failure containment. This paper details a lightweight carbon fiber composite chassis developed at Meggitt Sensing Systems (MSS) Securaplane, with a copper metallic mesh co-cured onto the internal surfaces resulting in a 50% reduction in weight when compared to its aluminum counterpart. In addition to significant weight reduction, it provides equal or improved performance with respect to EMI, structural and flammability performance.
2017-09-19
Technical Paper
2017-01-2029
Thibaut BILLARD, Cedric Abadie, Bouazza Taghia
Abstract The present paper reports non-electrically intrusive partial discharge investigations on aeronautic and electric vehicle motors fed by SiC inverter drive under variable environmental conditions. A representative test procedure and experimental set-up based on operating aeronautic conditions are essential to ensure the accuracy and reliability of partial discharge test on aircraft systems to make informed decisions on insulation system design choice. The aim of this paper is to demonstrate the feasibility of partial discharge test of the insulation system on a different type of motor under such conditions, both electrically and environmentally. To do so, the paper will start by detailing the innovative experimental set-up to be used in the study. It mainly consists in a high-voltage (1000V) inverter drive using SiC components to provide fast rise time surges.
2017-09-19
Technical Paper
2017-01-2053
Jim Stabile
Since oxygen has been a part of the aircraft system it has always been managed using a difficult metric to understand.......PSI. Today's technology has allowed us to efficiently and inexpensively convert PSI into a timed based metric which allows for improved oxygen management and a method which provides an interface between two important energy aircraft resources (fuel and oxygen). These resources have inverse consumption rates tied directly to the altitude of the aircraft. Using time as the management metric, the pilot can balance these 2 resources during any oxygen contingency by varying the altitude of the aircraft.. This allows for regulatory fuel savings and an increase in operational safety This program diverges from traditional thinking in that it applies an information and skill based solution to a system that has otherwise been viewed as a hardware problem.
2017-09-19
Technical Paper
2017-01-2058
Francesco Noziglia, Paolo Rigato, Enrico Cestino, Giacomo Frulla, Alfredo Arias-Montano
Abstract Innovative aircraft design studies have noted that uncertainty effects could become significant and greatly emphasized during the conceptual design phases due to the scarcity of information about the new aero-structure being designed. The introduction of these effects in design methodologies are strongly recommended in order to perform a consistent evaluation of structural integrity. The benefit to run a Robust Optimization is the opportunity to take into account uncertainties inside the optimization process obtaining a set of robust solutions. A major drawback of performing Robust Multi-Objective Optimization is the computational time required. The proposed research focus on the reduction of the computational time using mathematic and computational techniques. In the paper, a generalized approach to operate a Robust Multi-Objective Optimization (RMOO) for Aerospace structure using MSC software Patran/Nastran to evaluate the Objectives Function, is proposed.
2017-09-19
Technical Paper
2017-01-2077
John McClelland, Michael Morgan, Caroline McClory, Colm Higgins, Rory Collins, Adrian Murphy, Yan Jin
The need to drill several million holes per aircraft through composite and hybrid material stacks is a large challenge for the aerospace assembly process. The ability to produce high quality holes for the lowest tooling costs is at the forefront of requirements for aircraft assembly factories worldwide. Consequently, much research has been conducted into tool design and development, however, the effect of drilling platform characteristics has not been well covered in literature. Respectively, this research has compared the drilling abilities of a 5-axis precision CNC platform, a hybrid parallel kinematic machine and an articulated robotic arm fitted with a drilling module. In-process force measurement and post process hole and tool analysis methods were used to better understand the effect of static and dynamic platform characteristics on the achievable hole quality, cycle time and tool wear when drilling aerospace metal alloy stacks.
2017-09-19
Technical Paper
2017-01-2124
Violet Leavers
Abstract Within the aviation industry analysis of wear debris particles recovered from magnetic plugs and lubricating fluids is an essential condition monitoring tool. However, in large organisations, high staff turnover in remote work environments often leaves dangerous gaps in on-site support and background knowledge. The current work develops interactive software for wear debris particle classification, root cause diagnosis and serviceability prognostics. During the research several hundred wear debris particle images were collected, analysed and classified by a number of experts. At each stage of the analysis the experts were questioned about the knowledge and experience used to make their diagnoses and prognoses. The end result is an extensive knowledge base representing the combined expertise of a number of highly trained engineers, each with decades of hands-on experience.
2017-09-19
Technical Paper
2017-01-2123
Violet Leavers
Abstract The need to maintain aircraft in remote, harsh environments poses significant challenges. For example, in desert assignments or on-board carrier vessels where frequent rotation of staff with variable levels of skill and experience requires condition monitoring equipment that is not only robust and portable but also user friendly and requiring a minimum of training and skill to set up and use correctly. The mainstays of any on-site aircraft maintenance program are various fluid and particulate condition monitoring tests that convey information about the current mechanical state of the system. In the front line of these is the collection and analysis of wear debris particles retrieved from a component’s lubricating or power transmission fluid or from magnetic plugs. It is standard practice within the specialist laboratory environment to view and image wear debris using a microscope.
2017-09-19
Technical Paper
2017-01-2050
Piotr Synaszko, Michal Salacinski, Patryk Ciezak
Abstract The work concerns the selection of measurement parameters for selected non-destructive testing methods of Mi helicopter rotor blades after repair. Considered repair cases involve metal cracks in the sandwich skin and repair damage of honeycomb structure (puncture, dent). In the event of a crack, repair is performed by applying a composite-metal repair package. In case of damage of the core, its broken piece is replaced by a new one and then applied the same metal-composite package as in the case of crack repair. The present work focuses on detecting disbond between skin and core below repair patch and cracks under the repair package. Detecting cracks and assessing their length is important because the repair technology provides the repair package without removing of cracked part of skin. Authors have used laser shearography and C-scan methods for MIA and ET.
Viewing 1 to 30 of 15998