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2017-03-28
Technical Paper
2017-01-1124
Enrico Galvagno, Mauro Velardocchia
This paper investigates the effect of the powertrain mounting system on the linear and nonlinear torsional dynamical behaviour of a transmission system. To this aim, two dynamic models, namely rigid mounts model and flexible mounts model, are presented and compared, the first considering only the torsional dynamics of the transmission and driveline, the second considering also a 3 degrees-of-freedom powertrain block dynamics. The mechanical coupling and interaction between the powertrain block and transmission system is discussed and formulated. These models are then analysed in terms of vibrational mode shapes, natural frequencies and Frequency Response Functions (FRFs), considering also the sensitivity to the main transmission parameters on the system vibrations.
2017-03-28
Technical Paper
2017-01-0461
R. Rajendran, Ravikumar N, S.S.M Abdul Majeed
Brake disc provides friction force with minimum weight loss on application of brake. The pad material only experiences more wear and friction. Disc and pad materials are selected to give a stable and high coefficient of friction (0.25-0.40). COF is directly proportional to braking force generated and inversely proportional to the stopping distance. Brake pad is mainly produced from asbestos materials. Asbestos is an excellent material for brake pad application.. Considering the environmental pollution and human health safety, the asbestos cannot be used and there is a need to find an alternate material. The aim of the study is to identify a new material for replacement of pad material in practice. In this study, wear, hardness and friction properties of E glass fibre with epoxy resin and cashew friction dust composite are studied and compared with brake pad material in practice.
2017-03-28
Technical Paper
2017-01-1090
Praveen Kumar Tumu, KungHao Wang, Juhchin Yang, Selvakumar Palani, Balaji Srinivasan
In the shop floor, cracking issue was noticed during assembly of valve seat and valve guide in the engine cylinder head, especially near the valve seating area. This paper reveals a non- linear finite element methodology to verify the structural integrity of a cylinder head during valve seat and valve guide assembly press-in operation under the maximum material condition. Material and geometrical nonlinearities, and contact are included in this method to replicate the actual seat and guide press-in operation which is being carried out in shop floor. The press-in force required for each valve seat and valve guide assembly is extracted from simulation results to find out the tonnage capacity of pressing machine for cylinder head assembly line. Stress and plastic deformation due to assembly load are the criteria checked against the respective material yield.
2017-03-28
Technical Paper
2017-01-1122
Yashodhan V. Joshi
Vehicle noise has reduced over the years due to the customer demand for quieter vehicles. As engines have become quieter by efforts to reduce the combustion noise, as well as, by moving away from mechanical fuel pumps to common rail fuel pumps, the geartrain noise has come under increased scrutiny. Gear whine could be a result of multiple factors, and gear profile distortion is one of those factors. ISO 10064 provides guidance on the distortion due to temperature effects, but does not describe other influences in detail. There is not much published literature about gear whine due to profile distortion. The work attempts to fill that gap by describing a gear whine problem due to profile distortion and load change and it’s resolution by changing the gear design.
2017-03-28
Technical Paper
2017-01-0446
Xiao Chuan Xu
Aiming at the variable displacement oil pump, the modal and noise were studied, and structural optimization and test verification were carried out. The modal analysis of the variable displacement oil pump was carried out by ABAQUS. Three dimensional unsteady flow field in the variable pump was calculated by Pumplinx. Sound field was calculated by ACTRAN acoustic software. The NVH and comprehensive performance test of the oil pump was carried out by oil pump test bench and B&K PULSE vibration and noise test equipment. The modal of the variable displacement oil pump was analyzed by ABAQUS. Three dimensional unsteady flow field in the variable pump was calculated by Pumplinx. The sound field was calculated by ACTRAN acoustic software. The NVH and comprehensive performance test of the oil pump was carried out by oil pump test bench and B&K PULSE vibration and noise test equipment.
2017-03-28
Technical Paper
2017-01-1075
Wen Chen, Reda Adimi, Xingfu Chen, Todd Brewer, Ling Shi
In CAE analysis of cylinder bore distortion, valve seat distortion, valve guide-to-seat misalignment and cam bore misalignment, nodal displacements on the cylinder bore inner surface and on the gage lines of valve seats, valve guides and cam bores are typically output. Best fit cylinders, best fit circles and best fit lines are computed by utilizing the output displacements of the deformed configuration. Based on the information of the best fit geometry, distortions and misalignments are assessed. Some commercial and in-house software is available to compute the best fit cylinders, best fit circles and best fit lines. However, they suffer from the drawback that only one best-fit geometry can be computed at a time. For example, in the valve seat distortion analysis of a typical 4-cylinder, 4-valve engine, 16 best fit circles are needed.
2017-03-28
Technical Paper
2017-01-1091
Todd Brewer, Xingfu Chen
Typically, modern automotive engine designs include separate cylinder heads and cylinder blocks with a multilayer steel head gasket to seal the resulting joint. Cylinder head bolts are typically used to hold the joint together and non-linear properties of head gasket provide sealing capabilities of this joint, which is essential for engine durability and performance. There are three major failure modes for head gasket joint: fluid leakage due to low sealing pressure, bead cracking due to high gap alternation and scrubbing/fretting due to pressure and temperature fluctuations causing lateral movement in the joint. During engine operation, head gasket design should be robust enough to prevent all three failure modes. Analysis methods to address two failure modes (fluid leakage and bead cracking) are common within the industry. This paper will be focused on gasket scrubbing/fretting failure mode. First gasket scrubbing and fretting mechanisms are investigated.
2017-03-28
Technical Paper
2017-01-1316
Dhaval Vaishnav, Mohsen Ehteshami, Syed Ali, Vylace Collins, Alan Gregory, Matthew Werner
A jet pump, or an ejector, functions on the ability of a high velocity jet to entrain surrounding stationary fluid. When a high pressure flow from a primary inlet passes through a nozzle, it creates low pressure zone due to venturi effect. The low pressure zone allows flow entrainment from a secondary inlet. For a given pressure at primary inlet, it is desired to entrain maximum flow from secondary inlet. Jet pumps have been used in automobiles for a variety of applications such as: transferring liquid fuel between two halves of the saddle type fuel tank and entraining fresh coolant in the cooling circuit. Recently, jet pumps have been used in evaporative emission control system to remove gaseous hydrocarbons stored in carbon canister and supply it to intake manifold (canister purging). Naturally aspirated engines use vacuum pressure inside the intake manifold for canister purging. However, turbocharged engines operate at or above atmospheric pressure.
2017-03-28
Technical Paper
2017-01-0131
Chiranth Srinivasan, Chonglin Zhang, Haiyang Gao, De Ming Wang, Jody Slike
In an automotive cooling circuit, the wax melting process determines the net and time history of the energy transfer between the engine and its environment. A numerical process that gives insight into the mixing process outside the wax chamber, the wax melting process, and the effect on the poppet valve displacement will be advantageous to both the engine and automotive system design. A fully three dimensional, transient, system level simulation of an inlet controlled automotive cooling circuit is undertaken in this paper. A proprietary CFD algorithm, PumpLinx®, is used to solve this complex problem. A two-phase model is developed in PumpLinx® to simulate the wax melting process. The hysteresis effect of the wax melting process is also considered in the simulation. The coolant circulated using a centrifugal pump, which operates via a constant ratio with respect to the engine speed, is modeled as part of the computational domain.
2017-03-28
Technical Paper
2017-01-0387
Deepak Anand Subramanian, Shanmugam Mathaiya, Srinivasa Chandra V
In today's commercial vehicle scenario, designing and developing a component which will never fail throughout its lifespan is next to impossible. For a long time especially in the field of automotive, any crack initiation shall deem the component as failed and the design requires further modification. This paper deals with studying the failure of one such component and understanding the effect the crack has on the overall life of the component i.e. understanding the remnant life of the component. The component under study was gear shift lever bracket and is mounted on the engine exhaust manifold. It experiences two types of loads: inertial load due to the engine vibration and gear shift load. Frequent failures were observed in the field and in order to simulate it at lab, an accelerated test approach was adopted. The engine operating speed was used to identify the possible excitation frequency which the component might experience.
2017-03-28
Technical Paper
2017-01-1147
Hyunjun Kim, Jingeon Kang, Dongsuk Kum
Input- and output-split hybrids, which use a single planetary gear (PG), have a good fuel economy, but a relatively low acceleration performance. In order to improve their acceleration performance, speed reduction gears (SRG) have been employed in various commercialized split hybrids. However, the full potential of using SRGs has not yet been investigated. In fact, adding one SRG to input- or output-split hybrids can improve not only their acceleration performance, but also their fuel economy. Nevertheless, the design space of input- and output-split configurations using one SRG is huge; 864 configurations are using two PGs connected through one interconnection and having one node grounded to a fixed platform. Thus, in order to solve this high computational load problem, an efficient comprehensive design methodology is highly required.
2017-03-28
Technical Paper
2017-01-0445
Muthukumar Arunachalam, Arunkumar S, PraveenKumar Sampath, Abdul Haiyum
In recent years, there is increasing demand for every CAE engineer on their confidence level of the virtual simulation results due to the upfront robust design requirement during early stage of an automotive product development. Apart from vehicle feel factor NVH characteristics, there are certain vibration target requirements at system or component level which need to be addressed during design stage itself in order to achieve the desired functioning during vehicle operating conditions. Vehicle passive safety system is one of which primarily consists of acceleration sensors, control module and air-bag deployment system. As the sensors act as the front-end of passive safety system and control module’s decision is based on these sensors signals, its mounting locations should meet the sufficient inertance or dynamic stiffness performance in order to avoid distortion in signals due to its structural resonances.
2017-03-28
Technical Paper
2017-01-0250
Jizhou Zhang, Jianhua zhou PhD, Mian LI, Min Xu
To improve the system performance, precision manufacturing is required for production of the internal combustion engines (ICEs), a typical complex nonlinear system. Previous studies show that tolerances of critical dimensions have significant impacts on the engine performance. Among many critical factors, friction loss is one of the most important ones that affect the output performance of ICEs. It is necessary to recognize and control the tolerances which affect the friction loss. Of all the friction pairs for the engine, it is observed that the piston-cylinder friction pair and the bearing system take up nearly 70% of the total friction loss. In this work a novel multi-objective tolerance design optimization problem considering two friction systems mentioned above is proposed and solved. First two separated simulation models, the piston-cylinder and the bearing are built using AVL Excite Piston & Ring® and AVL Excite Power Unit®, respectively.
2017-03-28
Technical Paper
2017-01-0860
PengBo Dong, Jun Yamauchi, Keiya Nishida, Youichi Ogata
With the aim of improving engine performance, recent trend of fuel injection nozzle design followed by engineers and researchers is focusing on more efficient fuel break up, atomization, and fuel evaporation. Therefore, it is crucial to characterize the effect of nozzle geometric design on fuel internal flow dynamics and the consequent fuel-air mixture properties. In this study, the internal flow and spray characteristics generated by the practical multi-hole (10 holes) nozzles with different nozzle hole length and hole diameter were investigated in conjunction with a series of computational and experimental methods. Specifically, the CFD commercial code was used to predict the internal flow variation inside different nozzle configurations, and the high-speed video observation method was applied to visualize the spray evolution processes under non-evaporating conditions. Moreover, the Laser Absorption Scattering method was implemented to explore the spray evaporation characteristics.
2017-03-28
Technical Paper
2017-01-0543
Oliver Hofmann, Shijin Han, Daniel Rixen
This study discusses model-based injection rate estimation in common rail diesel injectors exhibiting aging phenomena. Since they result in unexpected injection behavior, aging effects like coking or cavitation may impair combustion performance, which justifies the need for new modeling and estimation approaches. To predict injection characteristics, a simulation model for the bottom section of the injector is introduced, with a main focus on modeling the hydraulic components. Using rail pressure and control piston lift as inputs, a reduced model is then derived in state-space representation, which may be used for the application of an observer in hardware-in-the-loop (HIL) environments. Both models are compared and validated with experimental data, with which they show good agreement. Aging efects and nozzle wear, which result in model uncertainties, are considered using a fault model in combination with an extended Kalman filter (EKF) observer scheme.
2017-03-28
Technical Paper
2017-01-1062
Abdelkrim Zouani, Gabriela Dziubinschi, Vidya marri, Simon Antonov
In modern automotive engines, Variable Displacement Oil Pump (VDOP) is becoming the pump of choice to reduce friction and deliver stringent fuel economy. However, this pump creates pressure ripples, at the outlet port during a complete shaft rotation, causing oscillating forces within the system and leading to the generation of tonal noises and vibrations. In order to minimize the level of noise different porting geometries and vane spacing are used. This paper presents an optimization method intended to identify the best possible spacing for the conventional 7-vanes and 9-vanes oil pumps. The method integrates a Matlab based oil pressure trace model into Mode Frontier computation platform. Bench tests are performed on several pumps with different vane spacing to measure the harmonics of the pressure ripples at the pump outlet in order to validate the results of the optimization study.
2017-03-28
Technical Paper
2017-01-0416
Vishal BARDE, Baskar Anthonysamy, Ganeshan Reddy, Senthil S, Visweswara lenka, Gurdeep Singh Pahwa
Power steering pump is vital component of hydraulic power steering system. Failure of steering pump can lead to loss of power assistance. Prediction of hub load on pump shaft is an important design input for pump manufacturer. Higher hub loads than design load of pump bearing can lead to seizure of pump. Pump manufacturer has safe limits for hub load. Simulations can assist for optimization of belt layout and placement of accessories to reduce the hub load. Lower hub load can have direct effect on improvement of pump durability. This paper deals with dynamic simulation of belt drive system in MSC.ADAMS as well as vehicle level measurement of hub load on power steering pump. Hub load is measured with two different belt layout as well as in different maneuver related to cranking and high speed conditions at which the worst load cases are seen.
2017-03-28
Technical Paper
2017-01-0011
Kesav Kumar Sridharan, Swaminathan Viswanathan
Current generation automobiles are controlled by electronic modules for performing various functions. These electronic modules have numerous semiconductor devices mounted on printed circuit board. Solders are generally used as thermal interface material between surface mount devices and printed circuit boards (PCB) for efficient heat transfer. In the manufacturing stage, voids are formed in solders during reflow process due to outgassing phenomenon. The presence of these voids in solder for power packages with exposed pads impedes heat flow and can increase the device temperature. Hence it is imperative to understand the effect of solder voids on thermal characteristics of semiconductor devices. But the solder void pattern will vary drastically during mass manufacturing. Replicating the exact solder void pattern and doing detail simulation to predict the device temperature for each of the manufactured module is not practical.
2017-03-28
Technical Paper
2017-01-1032
Xavier Llamas, Lars Eriksson
Downsizing and turbocharging with single or multiple stages has been one of the main solutions to decrease fuel consumption and harmful exhaust emissions, while keeping a sufficient power output. An accurate and reliable control-oriented compressor model can be very helpful during the development phase, as well as for engine calibration, control design, diagnostic purposes or observer design. A complete compressor model consisting of mass flow and efficiency models is developed and motivated. The proposed model is not only able to represent accurately the normal region measured in a compressor map but also it is capable to extrapolate to low compressor speeds. Moreover, the efficiency extrapolation is studied by analyzing the known problem with heat transfer from the hot turbine side, which introduces errors in the measurements done in standard gas stands.
2017-03-28
Technical Paper
2017-01-1333
Sasikumar P, C. Sujatha, Chinnaraj K.
In commercial vehicles, exhaust system is normally mounted on frame side members (FSM) using hanger brackets. These exhaust system hanger brackets are tested either as part of full vehicle durability testing or as a subsystem in a rig testing. During initial phases of product development cycle, the hanger brackets are validated for its durability in rig level testing using time domain signals acquired from mule vehicle test data. These signals are then used in uni-axial, bi-axial or tri-axial rig facilities based on their severity and the availability of test rigs. This paper depicts the simulation method employed to replicate the bi-directional rig testing through modal transient finite element analysis (FEA). The FEA analysis is carried out with the inclusion of rubber isolator modeling, meshing guidelines etc. FEA results are in good agreement with rig level test results.
2017-03-28
Technical Paper
2017-01-1066
Christoph Beerens, Alexander Mueller, Kimm Karrip
As emissions regulations and carbon footprint are more and more demandingly regulated, thermal efficiency of engine components must be optimized. Valve group components have to allow for ever increasing temperatures, endure aggressive condensate or even contribute directly to rising efficiency and emissions demands. MAHLE has developed a new technology in order to measure valve temperatures in real time, i.e. Transient Valve Temperature Measurement (TVTM). This is a complex methodology using thermocouples installed inside of the valves, offering the possibility to run the engine at different conditions, without any functional changes in the valve train system at all. Specifically valve rotation is not affected and thus temperatures all around the valve seat can be captured during rotation. The test is cost effective, using series’ components only.
2017-03-28
Technical Paper
2017-01-0460
Erina Yasuda, Hiroki Kobayakawa, Seiji Amano, Yuto Otsuki, Tomohiro Ukai
Recent development trends for automotive engines, arising in part from environmental issues and regulations, show increased development of hybrid vehicles and low fuel consumption vehicles. For example, the increase in use of start-stop engines and downsizing for weight reduction are progressing. As a result, the operating conditions for engine bearings are inevitably becoming more severe. For example, start-stop engines are subject to many more starting and stopping cycles over their lifetime than conventional engines .The lubrication oil present between the bearing and shaft is squeezed out, and the shaft comes into direct contact with the bearing. This could cause the increase in the wear amount of the bearing. It is confirmed that the resin overlay has superior wear resistance for wear caused by start-stop. The cast iron shaft without quenching treatment has been used in the engines for the cost reduction.
2017-03-28
Technical Paper
2017-01-1005
Yizhou Zhang, Jaal Ghandhi, David Rothamer
Measurements of the particle size distribution (PSD) provide important insight into the nature of particulate matter (PM) and its sources as stricter PM emission regulations (both mass & number based) are being implemented. A previous study by the authors suggested a link between the change in PSD shape and changing amounts of direct-injected fuel. In this study, the effect of direct-injected fuel on the PSDs from dual-fuel combustion strategies is investigated in greater depth. The PSD data were measured using a scanning mobility particle sizer (SMPS) and acquired in a light-duty single cylinder diesel engine operated using conventional diesel combustion (CDC) and two diesel/natural gas dual-fuel combustion strategies. Three different direct-injection (DI) fuels (diesel, 2,6,10-trimethyldodecane (farnesane), and a primary research fuel (PRF) blend) and two different injector nozzles were used in this study.
2017-03-28
Technical Paper
2017-01-0893
Marek Tatur, Kiran Govindswamy, Dean Tomazic
Demanding CO2 and fuel economy regulations are continuing to pressure the automotive industry into considering innovative powertrain and vehicle-level solutions. Powertrain engineers continue to minimize engine internal friction and transmission parasitic losses with the aim of reducing overall vehicle fuel consumption. Strip friction methods are used to determine and isolate components in engines and transmissions with the highest contribution to friction losses. However, there is relatively little focus on friction optimization of Front-End-Accessory-Drive (FEAD) components such as alternators and AC compressors. This paper will outline the development of a flexible test stand that allows for highly accurate torque measurements on such components under precisely controlled environmental boundary conditions and device loads.
2017-03-28
Technical Paper
2017-01-0323
Rosa Radovanovic, Samuel J. Tomlinson
Press-in-place gasket stability is required to maintain consistent and predictive sealing compression in a sealing joint utilizing a housing groove and a mating component sealing surface. Without proper balance between height of the groove and height of the gasket, the sealing joint can be compromised. It is industry standard to balance design variables with the desire to achieve long term sealability and gasket stability. The percent of gasket out of groove was varied to study the interactions of the design control and the resultant deviation of gasket centerline to the groove centerline. Finally, an optimal percentage of gasket out of groove is recommended.
2017-03-28
Technical Paper
2017-01-1709
Zhigang Wei, Sarat Das, Ryan Barr, Greg Rohrs, Robert Rebandt, Xiao Wu, HongTae Kang
Recent stringent government regulations on emission control and fuel economy drive the vehicles and their associated components and systems to the direction of lighter weight. However, the achieved lightweight must not be obtained by sacrificing other important performance requirements such as manufacturability, strength, durability, reliability, safety, noise, vibration and harshness (NVH). Additionally, cost is always a dominating factor in the lightweight design of automotive products. Therefore, a successful lightweight design can only be accomplished by better understanding the performance requirements, the potentials and limitations of the designed products, and by balancing many conflicting design parameters. The combined knowledge-based design optimization procedures and, inevitably, some trial-and-error design iterations are the practical approaches that should be adopted in the lightweight design for the automotive applications.
2017-03-28
Technical Paper
2017-01-0366
Xingyu Liang, Yuesen Wang, shuhe huang, guichun YANG, Lin Tang, Guoqi Cui
Due to the mechanical forces under high temperature and pressure conditions, the engine cylinders cross section will not be a round circle any more once they are installed. Therefore, both static and dynamic conditions can change the geometry of the cylinders. On the other hand, deformation of engine cylinder causes increasing lubricating oil consumption and abnormal wear, resulting of worse fuel economy and emissions. However, prediction of deformation on a liner has not been made because of the complication of conditions and structure. In this study, a V6 engine body model was built and meshed with Hypermesh suit software. Also, cylinder deformation under static condition has been simulated and analyzed. Basically, few parameters like pre-tightened force, structure and distribution of bolts have been investigated to figure out how the cylinder bore deformation behaves via finite element analysis. Also, a simple Matlab program had been developed to process the data.
2017-03-28
Technical Paper
2017-01-1313
Bao Wang, Jianhua zhou PhD, Min Xu
Manufacturing tolerances are inevitable in nature. For the bearings used in internal combustion engines, the manufacturing tolerances of roundness, which can be very close to the bearing radial clearance on scale, will affect the lubrication of the bearings. However, there is insufficient understanding of this mechanism. The current study aims to find out the effects of the amplitude and the phase of journal roundness in the shape of ellipse on the lubrication of engine bearings, and interaction impacts of these two factors are also studied. First the elastohydrodynamic (EHD) theory is applied to model the bearing as the roundness is only of a few microns and the EHD model can be more precise by considering the elastic deformation of the journal and the bearing bush. The analysis of the DOE results shows that the roundness amplitude decides the degree of the variation of the bearing friction power loss.
2017-03-28
Technical Paper
2017-01-0484
Harchetan Singh Aneja, Harmeet Singh, Aashish Parmar, Rohan Sharma
The automotive industry, known for its competitiveness & innovations globally, researches for continuous improvement of part performances along with reduction of cost & weight. These are amongst the top priority goals across all OEMs. In the long list of automobile parts, pipe clamps have paved their way of design through generations from being of metal to plastic that has expanded its scope of application & performance. In an automobile, plastic clamps are widely used to hold single or multiple water, fuel or brake pipes of various diameters to vehicle body at various locations such as underbody (prone to stone chipping) or engine room (prone to high temperatures), etc. Plastic clamps are preferred over metallic clamps for their cost, weight, performance & productivity. Primarily, in all application areas, a clamp must be able to hold the pipes with consistent & sufficient performance that is quantified through parameters such as thrust force and pipe removal force.
2017-03-28
Technical Paper
2017-01-1025
Qinghe Luo, Baigang Sun, Xi Wang
Hydrogen is the most promising way for energy carrier because it has fast combustion velocity, the wide range of sources and the cleaning of combustion products. The hydrogen internal combustion engine (HICE) with turbocharger has been used to solve the contradiction of the power density and controlling NOx. However, the selection of the compressor for HICE with turbocharger is very different from the traditional engines because of the gas fuel. Hydrogen as the gas fuel takes the cylinder volume, which will increase the pressure and reduce the mass flow rate of air in the cylinder. Thus, this paper put forward a new method for the HICE with turbocharger taking into account of the effect of hydrogen in the cylinder. This method can calculate the turbocharging pressure ratio and the mass flow rate of air through the target power and the general parameters such as the displacement of cylinder, the intake temperature of hydrogen and the equivalence ratio of the mixture.
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