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Viewing 181 to 210 of 15348
2017-03-28
Journal Article
2017-01-0389
Carlo Cantoni, Giampiero Mastinu, Massimiliano Gobbi, Federico Ballo, Giorgio Previati
Abstract The durability performance of brake hoses is a crucial issue for such components. Accelerated fatigue testing of brake hoses is necessary for understanding achievable lifetime, actually computation of durability is quite cumbersome due to the many different materials the hoses are made from. Despite SAE standards are available, accelerated testing of brake hoses subject to actual torsional and bending stresses seem important to provide relevant feedback to designers. In this paper, an innovative methodology for assessing the fatigue behavior of brake hoses of road vehicles is proposed. A dynamic testbed is specifically designed and realized, able to reproduce the actual assembly conditions of the hoses fitted into a vehicle suspension. The designed testbed allows to replicate actual loading conditions on the brake hoses by simulating the vertical dynamics and steering of the suspension system together with brake pressure.
2017-03-28
Journal Article
2017-01-1518
Emil Ljungskog, Simone Sebben, Alexander Broniewicz, Christoffer Landström
Abstract Many aerodynamic wind tunnels used for testing of ground vehicles have advanced ground simulation systems to account for the relative motion between the ground and the vehicle. One commonly used approach for ground simulation is a five belt system, where moving belts are used, often in conjunction with distributed suction and tangential blowing that reduces the displacement thickness of the boundary layer along the wind tunnel floor. This paper investigates the effects from aft-belt tangential blowing in the Volvo Cars Aerodynamic wind tunnel. First the uniformity of the boundary layer thickness downstream of the blowing slots is examined in the empty tunnel. This is followed by investigations of how the measured performance of different vehicle types in several configurations, typically tested in routine aerodynamic development work, depends on whether the tangential blowing system is active or not.
2017-03-28
Journal Article
2017-01-1512
Fuliang Wang, Zhangshun Yin, Shi Yan, Jia Zhan, Heinz Friz, Bo Li, Weiliang Xie
Abstract The validation of vehicle aerodynamic simulation results to wind tunnel test results and simulation accuracy improvement attract considerable attention of many automotive manufacturers. In order to improve the simulation accuracy, a simulation model of the ground effects simulation system of the aerodynamic wind tunnel of the Shanghai Automotive Wind Tunnel Center was built. The model includes the scoop, the distributed suction, the tangential blowing, the moving belt and the wheel belts. The simulated boundary layer profile and the pressure distribution agree well with test results. The baseline model and multiple design changes of the new Buick Excelle GT are simulated. The simulation results agree very well with test results.
2017-03-28
Journal Article
2017-01-1522
Thomas Blacha, Moni Islam
Abstract The aerodynamic development of the new Audi Q5 (released in 2017) is described. In the course of the optimization process a number of different tools has been applied depending on the chronological progress in the project. During the early design phase, wind tunnel experiments at 1:4 scale were performed accompanied by transient DES and stationary adjoint simulations. At this stage the model contained a detailed underbody but no detailed engine bay for underhood flow. Later, a full scale Q5 model was built up for the aerodynamic optimization in the 1:1 wind tunnel at Audi AG. The model featured a detailed underbody and engine bay including original parts for radiators, engine, axles and brakes from similar vehicles. Also the 1:1 experiments were accompanied by transient DES and stationary adjoint simulations in order to predict optimization potential and to better understand the governing flow.
2017-03-28
Journal Article
2017-01-1527
Felix Wittmeier
Abstract After being in operation since 1989, the 25% / 20% model scale wind tunnel of University of Stuttgart received its second major upgrade in 2016. In a first upgrade in 2001, a rolling road with a 5 belt system from MTS was installed. This system includes a steel center belt to simulate the road underneath the vehicle and four FKFS designed rubber belts for wheel rotation. The recent upgrade now enables the wind tunnel to be used not only for standard, steady state aerodynamic measurements but also for measurements of unsteady aerodynamic effects. This enables the use of the FKFS swing system as a standard measurement technique. Therefore, the former balance was replaced by a balance manufactured by AND with a high Eigenfrequency and the ability to sample the measurement data at up to 1000 Hz. The second large part of the upgrade was the replacement of the control system. With the new Wind Tunnel Control System (WCTS), control system.
2017-03-28
Journal Article
2017-01-1534
Nina Tortosa, David Schroeck, Tony Nagle, Guy Flynt
Abstract The General Motors Reduced Scale Wind Tunnel Facility, which came into operation in the fall of 2015, is a new state-of-the-art scale model aerodynamic test facility that expands GM’s test capabilities. The new facility also increases GM’s aerodynamic testing through-put and provides the resources needed to achieve the growing demand for higher fuel economy requirements for next generation of vehicles. The wind tunnel was designed for a nominal model scale of 40%. The nozzle and test section were sized to keep wind tunnel interference effects to a minimum. Flow quality and other wind tunnel performance parameters are on par with or better than the latest industry standards. A 5-belt system with a long center belt and boundary layer suction and blowing system are used to model underbody flow conditions. An overhead probe traverse system is installed in the test section along with a model positioning robot used to move the model in an out of the test section.
2017-03-28
Journal Article
2017-01-1549
Taro Yamashita, Takafumi Makihara, Kazuhiro Maeda, Kenji Tadakuma
Abstract In recent years, the automotive manufacturers have been working to reduce fuel consumption in order to cut down on CO2 emissions, promoting weight reduction as one of the fuel saving countermeasures. On the other hand, this trend of weight reduction is well known to reduce vehicle stability in response to disturbances. Thus, automotive aerodynamic development is required not only to reduce aerodynamic drag, which contributes directly to lower fuel consumption, but also to develop technology for controlling unstable vehicle behavior caused by natural wind. In order to control the unstable vehicle motion changed by external contour modification, it is necessary to understand unsteady aerodynamic forces that fluctuating natural wind in real-world environments exerts on vehicles. In the past, some studies have reported the characteristics of unsteady aerodynamic forces induced by natural winds, comparing to steady aerodynamic forces obtained from conventional wind tunnel tests.
2017-03-28
Journal Article
2017-01-0462
Marcel Meuwissen, Jippe Van Ruiten, Thijs Besseling, Robbert van Sluijs, Maik Broda, Brian Pearce, Fenton I. O'Shea
Abstract Fuel economy improvement efforts in engines have focused on reducing parasitic losses. This paper addresses the friction losses in the valve train chain drive system where about half of the losses is caused by the chain sliding on plastic guide and tensioner arm faces (Figure 1). Efforts have been made to reduce these friction losses by optimizing the chain link profile, the geometry of the guide and tensioner arm rails, and developments towards low friction materials. This paper describes the approach taken for the development of new low-friction chain tensioner arm plastic materials. The approach is characterized by building an understanding of the friction mechanisms and identifying the most critical material’s properties. A lab-scale test is used for a first assessment of the friction performance of materials. The correlation between this lab-scale test and the actual chain-on-tensioner arm application is discussed.
2017-03-14
Journal Article
2017-01-9275
Neng Zhu, Lin Lv, Chengwei Ye
Abstract In vehicles with urea-SCR system, normal operation of the urea-SCR system and engine will be influenced if there are deposits appearing on exhaust pipe wall. In this paper, a commercial vehicle is employed to study the influence factors of deposits through the vehicle road test. The results show that, urea injection rate, temperature and flow field have impacts on the formation of deposits. When decreasing the urea injection rate of calibration status by 20%, the deposit yield would reduce by 32%. If the ambient temperature decreased from 36 °C to 26 °C, the deposit yield would increase by 95%. After optimizing the exhaust pipe downstream of the urea injector by removing the step surface, only a few flow marks of urea droplets are observed on the pipe wall, and no lumps of deposits existing.
2017-01-10
Technical Paper
2017-26-0299
Mahesh Kishore Patekar, Jeevan Patil, Sivakumar Palanivelu, Bhupendra Bhat
Abstract Brake system is the most important system in the vehicle considering the overall vehicle safety and speed control. Brake applications are repetitive during a city traffic and hilly terrain on downhill gradient. Frequent braking gives rise to an overheating of the brake drum and its components. Braking operations at high temperature gives rise to problems like reduced deceleration due to loss of brake pad friction characteristics, pad softening and sticking to drum, pad distortion and wear etc. All these factors collectively result in deterioration of the braking performance and reduction of brake pad durability with time. Till date most of the thermal analysis performed for brake drum heating are through physical testing using brake system prototypes and by means of CFD tools. These methods are time consuming and expensive. There is a need for an alternative method to reduce physical trials and prototype building and reduce dependency on CFD analysis.
2017-01-10
Technical Paper
2017-26-0303
Ayan Bhattacharya, Naveen Malik, Sahil Jindal
Abstract Nowadays, Road Load Simulators are used by automobile companies to reproduce the accurate and multi axial stresses in test parts to simulate the real loading conditions. The road conditions are simulated in lab by measuring the customer usage data by sensors like Wheel Force transducers, accelerometers, displacement sensors and strain gauges on the vehicle body and suspension parts. The acquired data is simulated in lab condition by generating ‘drive file’ using the response of the above mentioned sensors [2]. For generation of proper drive file, not only good FRF but ensuring stability of inverse FRF is also essential. Stability of the inverse FRF depends upon the simulation channels used. In this paper experimental approach has been applied for the optimization of the simulation channels to be used for simulation of normal Indian passenger car on 4 corners, 6-Axis Road Load Simulator. Time domain tests were performed to identify potential simulation channels.
2017-01-10
Technical Paper
2017-26-0292
Irshad Mahammad, Vinay Nagaraj, Saurabh Prabhakar
Abstract To replicate on-road brake test cycle of cooling or heating through Computational Fluid Dynamics (CFD) simulations, the vehicle model with brake assembly must be solved in transient mode. However, such simulations require significant computational time owning to the physics involved in computing the variation of temperature with time. A methodology developed using commercial CFD tools to predict the Heat Transfer Coefficient (h), Cooling Coefficient (b) and rotor temperatures is described in this paper. All the three modes of heat transfer: conduction, convection and radiation are considered in the current method. Heat transfer coefficients from the CFD simulations are exported to Computer Aided Engineering (CAE) tools to validate the Brake Rotor Thermal Coning caused by high thermal gradients in brake rotor.
2017-01-10
Technical Paper
2017-26-0315
Jyoti Kale, Satish Kumar, Pravin Lavangare, Anand Subramaniam
Abstract The Steering system is one of the most safety critical systems in an automobile. With time the durability, reliability and the fine-tuning of the parameters involved in this subsystem have increased along with the competitiveness of the market. In a competitive market, accelerated testing is the key to shorter development cycles. It is observed that the majority of component manufacturers have a preference on vehicle level testing to achieve their development goals. The vehicle level trials are time consuming and lack the control and repeat-ability of a laboratory environment. This paper describes the development of a steering test rig designed to simulate the disturbances experienced on road within a controlled laboratory environment. The five axis steering rig would allow simulation of individual road wheel displacement along with steering wheel angle input and lateral steering rack displacements. The rig also is designed to be adaptable to a range of vehicle categories.
2017-01-10
Technical Paper
2017-26-0320
Pravin Lavangare, Ashutosh Jahagirdar, Parag Mengaji, Manish Karle, Anand Deshpande, Ujjwala Shailesh Karle, Ashok Kulkarni, Sreekumar Uthaman, Amol Dere
Abstract Automotive clutches form the most important component in the drive line which acts both as torque transmitter and as a fuse. Testing clutches, in the vehicle assembly, poses certain limitations. In this context the automotive clutch, as a component, needs to be evaluated to determine various performance parameters like wear, load loss, slipping torque, slipping time etc. to meet desired design, performance and durability requirements. It is very important to simulate engine and vehicle conditions in terms of operating environment, speed and load accurately while evaluating above parameters. This creates lot of challenges to design and develop a test rig capable of evaluating complete clutch performance. Very limited options are available for such test rigs worldwide. In India, no manufacturer provides such indigenous test rigs. Developing an indigenous, cost effective clutch test rig was the need of the hour.
2017-01-10
Technical Paper
2017-26-0336
Ganesh Liladhar Yewale, Abhishek Tapkire, D Radhakrishna, Popat Shejwal, Kaushal Singh, Gaurav Panchal
Abstract VRDE has developed Wankel type rotary engine to achieve high power output & fuel efficiency for indigenization programme of UAVs. This engine is meeting all performance parameters needed for intended aerial vehicle. This paper describes the testing methodology followed by development engineers to prove the endurance and reliability of UAV engine for airworthiness certification. This paper gives the brief about testing carried out on the Wankel engine, failures faced during endurance testing and their rectification to enhance the life of the engine to achieve hundred test cycle mark. This paper also briefs about the test set up, endurance test cycles simulating the practical operating conditions.
2017-01-10
Technical Paper
2017-26-0327
Onkar Deshpande, Shrikant Rangire
Abstract Increase in customer awareness for better vehicle noise together with strict pass-by noise limits have compelled the automotive industry to improve the overall vehicle noise performance. Out of various contributors to the overall vehicle noise, tail pipe noise is the major contributor. There is a need of efficient tail pipe noise measurement process for tuning the exhaust system. Modified methodology was proposed as conventional methodologies have limitations considering Indian scenario. In modified methodology tail pipe noise is measured during pass by noise test. This paper describes the comparative study of both methodologies with measurement results. Advantages and disadvantages of both measurement methodologies are also discussed.
2017-01-10
Technical Paper
2017-26-0325
Anup Batra, Sreenivasa Gupta, Husain Agha, K Rajakumar, Rajiv Modi
Abstract With the advancement in vehicle technology over the years, many intuitive technologies are coming in automotive passenger vehicles to improve the safety aspects during vehicle driving in night conditions. In addition to headlamps, cornering lamps or infrared camera with head up display etc. are evolving as a part of AFS (Advanced Front Lighting Systems) to aid driver vision. Many OEMs are following conventional methodology of subjective assessments with the ratings on different numerical scale mapped with customer acceptance to validate head lamps and its tech updates. These methods lag in getting repeatability of results, acceptance reliability and not knowing the limitations of the installed system due to high dependency on the selected evaluators. This paper emphasizes on robust test methodology development to validate the complete performance of cornering lamps with the objective test data analysis.
2017-01-10
Technical Paper
2017-26-0326
Michael Wohlthan, Gerhard Pirker, Igor Sauperl, Andreas Wimmer, Wolfram Rossegger, Norbert Buch
Abstract Experimental investigations on engine test beds represent a significant cost in engine development. To reduce development time and related costs, it is necessary to check the quality of measurements automatically whenever possible directly on the test bed to allow early detection of faults. A fault diagnosis system should provide information about the presence, cause and magnitude of an inconsistency in measurement. The main challenge in developing such a system is to detect the fault quickly and reliably. However, only faults that have actually occurred should be detected because the user will only adopt a system that provides accurate results. This paper presents a methodology for automated fault diagnosis at engine test beds, starting with an explanation of the general procedure. Next, the methods applied for fault detection are introduced.
2017-01-10
Technical Paper
2017-26-0322
Saktheeswaran Kasinathan, Sreenivasa Gupta, Husain Agha, Rajiv Modi
Abstract In any industry, early detection and mitigation of a failure in component is vital for feasible design changes or development iterations or saving money. So it becomes pivotal to capture the failure mode in an accelerated way. This theory poses many challenges in devising the methodology to validate the failure mode. In real world, vehicle head lamp is exposed to all possible kinds of harsh environments such as variable daily ambient, rain, dust and engine compartment temperature …etc. This brings rapid thermal stress onto headlamp resulting into warpage cracks. At vehicle level on particular model, this failure is typically observed after 20,000-25,000 kms in a span of 3-4 months of running. Any corrective action to revalidate the design change or improvement will need similar timelines in regular way to test, which is quite high in product development cycle.
2017-01-10
Technical Paper
2017-26-0340
Sarang Bire, Prashant R Pawar, M Saraf
Abstract Air suspension systems had been introduced in automobiles since 1950s. These systems are being explored to improve the ride comfort, handling stability and also serve as a medium for better cargo protection. These system are well developed for buses and high end passenger sedans, also have feasibility for adapting for wide range of configurations of suspension system and axle. Passenger cars and Sports Utility Vehicle (SUV) pickup category of vehicle offers different challenges such as space availability, spring selection and characterization that need to be addressed for successful implementation of air suspension in these category vehicles. This work defines methodology to implement air suspension system in SUV Pickup category vehicle. Paper work includes concept study, mathematical co-relation, and prediction of air spring characteristics and integration of experimental and analytical tool for development of air suspension system.
2017-01-10
Technical Paper
2017-26-0369
R Muthuraj, Sundararajan Thiyagarajan, E Vignesh, C Kannan, Deepa Praphu
Abstract Overheating in commercial vehicles, even though if it’s in LCV segment, is a problem of high significance. There could be various level of problems that may arise due to heat generation resulting from braking (oversized brake drums left the wheels with lesser packaging clearances for air flow and cooling) and some of them are: 1. Early tire wear /reduction in tire life, 2. Air valve heat damage /air leak issues, 3. Frequent puncture problems, 4. Failure of other mating components and other heat initiated failures. However optimum the vent hole shape in a wheel may be, the air flow in the vicinity of drum periphery and wheel rim ID wouldn’t be sufficient enough because of the lesser clearance and packaging space as mentioned earlier. The basic construction of a wheel with disc welded to rim base ID was apparently modified to integrate the disc and gutter and weld it to rim OD.
2017-01-10
Technical Paper
2017-26-0181
Manish Vyas, Mark Pratley
Abstract There is an increased use of elastomers in the automotive industry for sealing, noise isolation, load dampening, insulation, etc., because of their key properties of elasticity and resilience. Elastomers are used in supercharger application for dampening the torsional fluctuation from the engine, to reduce noise issues. Finite element modeling of elastomers is challenging because of its non-linear behavior in different loading directions. It also undergoes very large elemental deformation (~up to 200%), which results in additional complexities in getting numerical convergence. Finally, it also exhibits viscous and elastic behavior simultaneously (viscoelastic effect) and it undergoes softening with progressive cyclic loading (Mullins effect). The present study deals with the characterization of elastomers for its modeling in commercial finite element software packages and verification of some predicted design parameters with physical testing.
2017-01-10
Technical Paper
2017-26-0195
Sachin Kumar Jain, Manasi Joshi, Harshal Bankar, Prashant Kamble, Prasad Yadav, Nagesh Karanth
Abstract The paper discusses the methodology for measuring the sound absorption of sound package materials in a different sizes of reverberation chambers. The large reverberation chamber is based on test methods and requirements as per ASTM C423 and ISO 354 standards. Both the test standards are similar and recommend a reverberation chamber volume of at least 125 m3 and 200 m3 respectively for sound absorption measurements from 100 Hz to 5000 Hz. The test sample size requirements are from 5.5 to 6.7 m2 as per ASTM C423 and 10 to 12 m2 as per ISO 354. In the automotive sector passenger car, heavy truck, and commercial vehicle, the parts that are used are much smaller in size than the size prescribed in both the standards. The requirement is to study the critical parameters such as the chamber volume, sample size, reverberation time and cut-off frequency etc. which are affecting the sound absorption property of acoustic material.
2017-01-10
Technical Paper
2017-26-0111
MY Raghu, Prashant Sharma
Abstract In recent times diesel powered vehicles are becoming popular due to improved performance and reduced exhaust emission with this the market share of diesel passenger cars expected to approach 60 % over the next few years. In compliance with future emission standards for diesel powered vehicles, it is required to use diesel particulate filters (DPF) along with other exhaust emission control devices. There is a need for more optimized DPF cell structure to collect maximum soot load with low pressure drop and improved exhaust performance from diesel vehicles in Indian driving conditions. In this thesis paper a detailed parametric study have been carried out on different DPF cell structures like Square, Hexagonal and combined cell geometry. The performances of different cell structure has been evaluated for maximum soot loading capacity and regeneration rate, pressure drop, temperature distribution across cell structure.
2017-01-10
Technical Paper
2017-26-0094
Shi Li, Michael Stapelbroek, Jan Pfluger
Abstract With the increasing application of the lithium ion battery technology in automotive industry, development processes and validation methods for the battery management system (BMS) have drawn more and more attentions. One fundamental function of the BMS is to continuously estimate the battery’s state-of-charge (SOC) and state-of-health (SOH) to guarantee a safe and efficient operation of the battery system. For SOC as well as SOH estimations of a BMS, there are certain non-ideal situations in a real vehicle environment such as measurement inaccuracies, variation of cell characteristics over time, etc. which will influence the outcome of battery state estimation in a negative way. Quantifying such influence factors demands extensive measurements. Therefore, we have developed a model-in-the-loop (MIL) environment which is able to simulate the operating conditions that a BMS will encounter in a vehicle.
2017-01-10
Technical Paper
2017-26-0072
Moqtik Bawase, M R Saraf
Abstract Utilization of higher ethanol blends, 20% ethanol in gasoline (E20), as an alternate fuel can provide apparent benefits like higher octane number leading to improved anti-knocking properties, higher oxygen content resulting in complete combustion. Apart from technical benefits, use of ethanol blends offer certain widespread socioeconomic benefits including option of renewable source of energy, value addition to agriculture feedstock resulting in increase in farm income, creation of more jobs in rural sector and creating job at local levels. Use of higher blends of ethanol can reduce dependence on foreign crude leading to substantial savings in cost of petroleum import. The impact of higher Gasoline-Ethanol blend (E20), on the fuel system components of gasoline vehicles must be known for assessment of whether the fuel system will be able to perform as intended for the complete design life of the system.
2017-01-10
Technical Paper
2017-26-0152
Serge Lievens, Bjorn Van Gasse, Sandra Claeys, Jurgen De Kimpe, Amol Chore
Abstract In conjunction with modern engine design and long term reliability needs, the resistance of engine coolants to oxidative stress has become an increasingly important feature. This paper describes the results of a study that evaluated the influence of parameters such as temperature, aeration and catalytic metal interaction on the oxidation stability of engine coolants. Three different test set-ups were used in which the selected conditions put variable weights to the contribution of each parameter. A comparison was made of the oxidation resistance of multiple high quality OEM approved coolant products with different additive technologies. This work is different from previous investigations focusing mainly on the behavior of coolants in single test conditions.
2017-01-10
Journal Article
2017-26-0242
Guido Tosolin, Kwang Chan Ko
Abstract A vehicle simulation model is developed, validated and integrated into a closed-loop virtual driving environment using a state-of-the-art hexapod driving simulator. Thirty variant states are implemented and evaluated subjectively on steering and handling performance quality and quantity. Standard open-loop objective testing manoeuvres are simulated and performance metrics are calculated, allowing for a systematic cross-correlation process. Graphical analysis of the correlation metrics proves that chassis changes may accurately be felt through the simulator interface. It is proposed how obtained correlation models may serve for driver-feel optimizing target setting in early vehicle development stages, frontloading a great deal of costly prototype testing. System requirements are established and benefits and limitations are portrayed.
2017-01-10
Technical Paper
2017-26-0130
Hemant P. Urdhwareshe
Abstract In the recent times, there have been number of cases of failure to pass the COP tests. When a vehicle fails a COP test, it is very embarrassing and expensive for the manufacturer as there is a loss of faith by the society and consumers. It is also painful for the certification agency as well as government. In this context, it is important to quantify and minimize the risk associated with these tests for manufacturers as well as certification agencies. The sampling plan specified in MoRTH / CMVR / TAP-115 is designed to quickly pass vehicles which have very low emissions and quickly reject (fail) vehicles having higher emissions compared to the specified limit. These sampling plans can be classified under Probability Ratio Sequential Tests (PRST).
2017-01-10
Journal Article
2017-26-0364
Igor Gritsuk, Vladimir Volkov, Vasyl Mateichyk, Yurii Gutarevych, Mykola Tsiuman, Nataliia Goridko
Abstract The article suggests the results of experimental and theoretical studies of the engine heating system with a phase-transitional thermal accumulator when the vehicle is in motion in a driving cycle. The aim of the study is to evaluate the efficiency of the vehicle heating system within thermal accumulator and catalytic converter under operating conditions. The peculiarity of the presented system is that it uses thermal energy of exhaust gases to accumulate energy during engine operation. The article describes the methodology to evaluate vehicle fuel consumption and emission in the driving cycle according to the UNECE Regulation № 83-05. The methodology takes into account the environmental parameters, road conditions, the design parameters of the vehicle, the modes of its motion, thermal state of the engine cooling system and the catalytic converter.
Viewing 181 to 210 of 15348