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Viewing 1 to 30 of 33298
2017-10-08
Technical Paper
2017-01-2202
Shiyou Yang
This work presents an application of two sub-models relative to chemical-kinetics-based turbulent pre-mixed combustion modeling approach on the simulation of burn rate and emissions of spark ignition engines. In present paper, the justification of turbulent pre-mixed combustion modeling directly based on chemical kinetics plus a turbulence model is given briefly. Two sub-models relative to this kind of pre-mixed combustion modeling approach are described generally, including a practical PRF (primary reference fuel) chemical kinetics mechanism which can correctly capture the laminar flame speed under a wide range of Ford SI (spark ignition) engines/operating conditions, and an advanced spark plug ignition model which has been developed by Ford recently.
2017-10-08
Technical Paper
2017-01-2432
Xiangwang Li, Weimin wang, Xiongcai zou, Zhiming Zhang, Wenlong zhang, Shemin zhang, Tao Chen, Yuhuang cao, Yuanda Chen
In order to reduce emissions, size and manufacturing cost, integrated exhaust manifold become popular in gasoline engine, especially in three-cylinder engine. Moreover, due to shorter length, lighter weight, and less component connections, the exhaust manifold and hot end durability will improve apparently. In this work, an advanced cylinder head with integrated exhaust manifold is in adopted in one three-cylinder turbo engine. Because of this integration characteristic, the gas retain in cylinder head longer and the temperature reach higher level than normal cylinder head, which will cause thermal fatigue failure more easily. To validate the exhaust manifold and hot end durability, series simulation and test validation work have been done. Firstly, overall steady state and transient temperature simulation was done for global model. The global model include cylinder head, block, turbocharger, and catalyst components.
2017-10-08
Technical Paper
2017-01-2446
Pengchuan Wang, Nikolaos Katopodes, Yuji Fujii
Wet clutch packs are the key component for gear shifting in the step-ratio automatic transmission system. They are coupled or de-coupled to alter gear ratios based on driver’s demand and vehicle operating conditions. The frictional interfaces between clutch plates are lubricated with automatic transmission fluid (ATF) for both thermal and friction management. In a 10-speed transmission, there may be as many as 6 clutch packs. Under any driving conditions, 2 to 3 clutch packs are typically open, shearing ATF and contributing to energy loss. There is an opportunity to improve fuel economy by reducing this viscous drag. One main factor that directly affects clutch drag is the clearance between rotating plates. The axial position of clutch plates changes continually at every instance. It is empirically known that not only the total clearance, but also its distribution between the plates affects the viscous drag.
2017-10-08
Technical Paper
2017-01-2201
Zhongye Cao, Tianyou Wang, Kai Sun, Lei Cui
In uniflow scavenged two-stroke marine diesel engines, the main function of scavenging process is to replace the burned gas with fresh charge. It is integral to the subsequent combustion process, thereby affecting the engine's fuel economy, power output and emission performance. In this paper, a complete working cycle of 6S35ME engine of MAN Diesel&Turbo was simulated by using the CFD software CONVERGE with full engine geometry including intake and exhaust ports. The simulation based on RANS and standard k-epsilon model was in good agreement with experiment. Based on the above calibrated model, the influence of exhaust valve closing (EVC) timing and swirl ratio on the scavenging process were investigated.
2017-10-08
Technical Paper
2017-01-2256
Muhammad Umer Waqas, Bengt Johansson, Jean-Baptiste MASURIER, Kai Morganti
Future internal combustion engines demand higher efficiency, progression towards is limited by antiknock quality of present fuels and energy economics in octane enhancement. A possible solution is Octane-on-Demand, that uses a combination of high and low octane fuels in separated tanks to generate fuels of the required octane rating according to demand. Methanol, a RON 109 fuel was selected as the high octane fuel and five low octane fuels were used as base fuel. These were FACE (Fuels for Advanced Combustion Engines) gasolines, more specifically FACE I, J and A and their primary reference fuels (iso-octane/n-heptane). Experiments were conducted with a modified Cooperative Fuel Research (CFR) engine. For SI combustion mode the CFR operated at RON and MON conditions. The engine i.e. also operated in HCCI mode to get the auto ignition properties at lean conditions (λ=3).
2017-10-08
Technical Paper
2017-01-2197
Vignesh Pandian Muthuramalingam, Anders Karlsson
Owing to increased interest in blended fuels for automotive applications, a great deal of understanding is sought for the behavior of multicomponent fuel sprays. This sets a new requirement on spray model since the volatility of the fuel components in a blend can vary substantially. It calls for careful solution to implement the differential evaporation process concerning thermodynamic equilibrium while maintaining a robust solution. This work presents the Volvo Stochastic Blob and Bubble (VSB2) spray model for multicomponent fuels. A direct numerical method is used to calculate the evaporation of multicomponent fuel droplets. The multicomponent fuel model is implemented into OpenFoam CFD code and the case simulated is a constant volume combustion vessel. The CFD code is used to calculate liquid penetration length for surrogate diesel (n-dodecane)-gasoline (iso-octane) blend and the result is compared with experimental data.
2017-09-23
Technical Paper
2017-01-1953
Manfei Bai, Lu Xiong, Zhiqiang Fu, Renxie Zhang
Abstract: In this paper, a speed tracking controller is designed for the All-terrain vehicles. The method of feedforward with state variable feedback based on conditional integrators is adopted by the proposed control algorithm. The feedforward is designed considering the influence of the road slope on the longitudinal dynamics, which makes the All-terrain vehicles satisfy the acceleration demand of the upper controller when it tracks the desired speed on the road with slope varying greatly. The road slope is estimated based on a combined kinematic and dynamic model. This method solves the problem that road slope estimation require an accurate vehicle dynamic model and are susceptible to acceleration sensor bias. Based on the vehicle dynamic model and the nonlinear tire model, the method of conditional integration is used in the state variable feedback, which considers the saturation constraint of the actuator with the intention of preventing the divergent integral operation.
2017-09-23
Technical Paper
2017-01-1954
Peng Hang, Xinbo Chen, Fengmei Luo
Path tracking is the rudimentary capability and primary task for autonomous ground vehicles (AGVs). In this paper, a novel four-wheel-independent-steering (4WIS) and four-wheel-independent-drive (4WID) electric vehicle (EV) is proposed which is equipped with steer-by-wire (SBW) system. Compared with conventional front-wheel-steering (FWS) vehicles, 4WIS and 4WID EV has superior maneuverability, handing stability and path-tracking capability thanks to more actuators. Therefore, it is more suitable for a desired AGV. For path-tracking controller design, the nonlinear vehicle model with 2 degrees of freedom (DoF) is built utilizing the nonlinear Dugoff tire model. The nonlinear dynamic model of SBW system is conducted as well considering the external disturbances.
2017-09-23
Technical Paper
2017-01-1958
Motion Planning of Automatic Driving in Complex Traffic Scenarios With the increasing complexity, dynamicity and uncertainty of traffic, motion planning of automatic driving is getting more difficult and challenging. This paper focuses on the real-time motion planning problem of connected and automated vehicles in complex traffic scenarios. To effectively solve this problem, a general driving risk model is presented, which contains the following two essential parts: i) collision risk, i.e., the collision risk between the subject vehicle and other surrounding vehicles, pedestrians, buildings etc.; ii) non-collision risk, such as violation of traffic regulations, the difference between the actual operation state of the subject vehicle and the intention of driver, etc. In order to achieve the real time collision detection, the subject vehicle is approximated to a dot and its shape is considered by extending the dimension of obstcales considering their relative position and velocity.
2017-09-23
Technical Paper
2017-01-1955
Yandong Ruan, Hui Chen, Jiancong Li
An integrated automatic driving system consists of perception, planning and control. As one of the key component of autonomous driving system, the longitudinal planning module guides the vehicle to accelerate or decelerate automatically on the roads. A complete longitudinal planning module is supposed to consider the flexibility to various scenarios and multi-objective optimization including safety, comfort and economy. However, most of the current longitudinal planning methods can not meet all the requirements above. In order to satisfy the demands mentioned above, a new Potential Field (PF) based longitudinal planning method is presented in this paper. Firstly, a PF model is constructed to depict the potential risk of surrounding traffic entities, including obstacles and roads. The shape of each potential field is closely related to the property of the corresponding traffic entity.
2017-09-23
Technical Paper
2017-01-1966
Min Ke, Bing Zhu, Jian Zhao, Weiwen Deng
Aimed to keep a balance between positioning accuracy and running cost, this paper proposed an integrated positioning method based on GPS and UWB for the commercial applications of intelligent vehicle’s navigation and position system. When the vehicle is traveling in a wide area and the received GPS signal is good, the positioning results of Dead-Reckoning system are corrected by the low frequency positioning parameters output by GPS. During the correcting process, in order to realize the better fusion of measuring data, a simplified federal Kalman filter was designed by using indirect method. But when the vehicle is traveling in someplace making GPS signal failure such as city tunnel, the positioning results from UWB independent technology are adopt to replace the GPS signal for vehicle integrated positioning.
2017-09-23
Technical Paper
2017-01-1970
Guizhen Yu, Zhangyu Wang, Xinkai wu, yalong ma, yunpeng wang
In this paper, an efficient lane detection using deep feature extraction method is proposed to achieve real-time lane detection in diverse road environment. The method contains three main stages, 1)pre-processing, 2)deep lane feature extraction and 3)lane fitting. In pre-processing stage, the inverse perspective mapping (IPM) is used to obtain a bird's eye view of the road image, and then an edge image is generated using the canny operator. In deep lane feature extraction stage, an advanced lane extraction method is proposed. Firstly, line segment detector (LSD) is applied to achieve the fast line segment detection in the IPM image. After that, a proposed adaptive lane clustering algorithm is employed to gather the adjacent line segments generated by the LSD method. Finally, a proposed local gray value maximum cascaded spatial correlation filter (GMSF) algorithm is used to extract the target lane lines among the multiple lines.
2017-09-23
Technical Paper
2017-01-1982
Xiaoming Lan, Hui Chen, Xiaolin He, Jiachen Chen, Yosuke Nishimura, Kazuya Ando, Kei Kitahara
In recent years, the interaction between human driver and Lane Keeping Assistance System (LKAS) has gradually aroused concern. As a result, the concept of personalized LKAS is being put forward. To achieve the concept, driver lane keeping characteristic (DLKC) indices which could distinguish different driver lane keeping behavior are essential for LKAS to be adaptive to personal DLKC. However, there are few researches on DLKC indices for personalized LKAS. Although there are many researches on modeling driver steering behavior, these researches are insufficient to extract DLKC indices. Firstly, most of researches are for double lane change behavior which is different from driver lane keeping. Secondly, few researches on lane keeping behavior only provided model structure and rarely discussed about modeling details, such as how to select model data, how to define driver desired center line and so on. In this paper, DLKC indices for personalized LKAS were deeply researched.
2017-09-23
Technical Paper
2017-01-1988
XueFei Deng, Lu Che, Lei Zhang, Rong Sun
With the rapid economic development, path problem of refined oil distribution vehicle has been paid more and more attention. Which multi- compartment vehicle has obvious advantages because it can deliver many kinds of oil at the same time. This paper takes into account the conditions such as time window, multi-distribution center and simultaneous distribution of various oil products. How to optimize the transportation route, reduce the cost of distribution process and reduce the distribution cost and carbon emission in the background of low-carbon logistics, , To improve business income, to solve the oil companies in the distribution process is very concerned about the issue. In this paper, the routing optimization problem of multi- compartment vehicle is considered, which is based on the multiple distribution center with the time window, to reduce the carbon emissions, which mainly refers to greenhouse gases, such as carbon dioxide emissions.
2017-09-23
Technical Paper
2017-01-2013
Zhe Xu
The rapid development of connected vehicle technology provides a promising platform for traffic monitoring and traffic data collection. In connected vehicle environment, the vehicles equipped with wireless communication devices can transmit vehicle safety messages to other connected vehicles and the Roadside Unit (RSU). The trajectory information in the safety message may provide potential usage for traffic states estimation. Over the last few years, the applications of a macroscopic traffic flow model, the Macroscopic Fundamental Diagram (MFD) has attracted increased attention. However, the detection of MFD remains a challenging task even with probe vehicle data from mobile GPS, Bluetooth, and cellphone sensors. This paper explores a potential method of observing the MFD through Vehicle-to-Infrastructure (V2I) connected vehicle data.
2017-09-23
Technical Paper
2017-01-1952
ChengJun Ma, Fang Li, Chenglin Liao, Lifang Wang
With the increasing number of vehicles, the load of urban traffic system becomes more serious, and the Automatic Parking System (APS) plays an important role in alleviating the burden of drivers and improving vehicle safety. Therefore, it is essential to study high performance automatic Parking technology. The APS is consisted of environmental perception, path planning and path following.The path following controls the lateral movement of vehicle during the parking process, and requires the trajectory tracking error to be as small as possible. At present, some control algorithms are used including PID control, pure pursuit control, etc. However, these algorithms relying heavily on parameters and environment, have some problems under large curvature conditions, such as slow response and low precision. To solve this problem, a path following control method based on Model Predictive Control (MPC) algorithm is proposed in this paper.
2017-09-23
Technical Paper
2017-01-1981
Bing Zhu, Weinan Li, Ning Bian, Jian Zhao, Weiwen Deng
Driver individualities is crucial for the development of the Advanced Driver Assistant System (ADAS). Due to the mechanism that specific driving operation action of individual driver under typical conditions is convergent and differentiated, the driver individualities recognition method is constructed in this paper under typical conditions by using random forest model. A driver behavior data acquisition system was built using dSPACE real-time simulation platform. Based on that, the driving data of the tested driver were collected in real time under typical driving conditions. Then, we extract main driving data by principal component analysis method. The fuzzy processing is carried out on the main driving data, and the fuzzy matrix is constructed according to the intrinsic attribute of the driving data. The clustering relationship is determined by certain membership degree, and the driver's driving data is divided into multiple clusters.
2017-09-23
Technical Paper
2017-01-1951
Lingfei Wu, Hongshan ZHA, Caijing X, Qiaojun He
Local path planning for obstacle avoidance is one of the core topics of intelligent vehicle. A novel method based on dubins curve and tentacle algorithm is proposed in this article, with the consideration of obstacle avoidance and vehicle motion constraints. First, the preview distance of the vehicle is given according to the current speed, so that the preview point can be found with the information of global path. Then dubins curve is adopted to find a path with appropriate turning radius between the current position and preview point, satisfying the constraints of current direction and target direction, and considering handling and ride comfort of the vehicle. In order to avoid obstacle, tentacle algorithm is adopted. 20 tentacle points are given by moving the original preview point, and then 21 local paths can be got by using dubins curve. Cost function is used to find out the best option of the 21 paths.
2017-09-19
Technical Paper
2017-01-2144
Michele Trancossi, Mohammad Hussain, Sharma Shivesh, Jose Pascoa
This paper is a preliminary step in the direction of the definition of a radically new wing concept that has been conceived to maximize the lift even at low speeds. It is expected to equip new aerial vehicle concepts that aim to compete against helicopters and tilt rotors. They are expected to achieve very good performance at very low speed (5 to 30 m /s) by mean of an innovative concept of morphing ducted-fan propelled wing that has been designed to maximize the lift force. This paper presents an effective bibliographic analysis of the problem that is a preliminary necessary step in the direction of the preliminary design of the wing and the vehicle.
2017-09-19
Technical Paper
2017-01-2017
Catherine Ninah, Brian Strevens, Cole Barcia, Isabelle Labbe, Michael Frenna, Austin Faulconer, Keon Habbaba, Katherine Loundy, Louis Schaefer, Alexa Frost, Andrew Foran, Robert Brown, Luis Rabelo
National Aeronautics and Space Administration (NASA) is preparing for a manned mission to Mars to test the sustainability of civilization on the planet Mars. Our research explores the requirements and feasibility of autonomously producing fuel on Mars for a return trip back to Earth. As a part of NASA’s initiative for a manned trip to Mars, our team’s work creates and analyzes the allocation of resources necessary in deploying a fuel station on this foreign soil. Previous research has addressed concerns with a number individual components of this mission such as power required for fuel station and tools; however, the interactions between these components and the effects they would have on the overall requirements for the fuel station are still a mystery to NASA. By creating a baseline discrete-event simulation model in a simulation software called Simio, the research team has been able to replicate the fuel production process on Mars.
2017-09-19
Technical Paper
2017-01-2018
Won Il Jung, Larry Lowe, Luis Rabelo, Gene Lee, Ojeong Kwon
Operator training using a real weapon in a real-world environment is risky, expensive, time-consuming, and restricted to the given environment. The simulator, or a virtual simulation, is usually employed to solve these limitations. As the operator is trained to maximize weapon effectiveness, the effectiveness-focused training can be completed. However, the training was completed in limited scenarios without guidelines to optimize the weapon effectiveness for an individual operator, thus the training will not be effective with a bias. For overcoming this problem, we suggest a methodology on guiding effectiveness-focused training of the weapon operator using big data and Virtual and Constructive (VC) simulations. Big data, which includes structured, unstructured, and semi-structured types, are generated by VC simulations under a variety of scenarios.
2017-09-19
Technical Paper
2017-01-2020
Michael Croegaert
Modern military aircraft platforms are using more and more power which results in an ever increasing power density (SWaP). This in turn, generates more heat that has to be dissipated from the instrument panel and cockpit of the aircraft. Complicating this further is that the use of structural composites which are not efficient conductors of heat and the mission requirements of small heat signatures. Therefore alternative means of extracting the heat from the avionics systems must be used. Liquid cooled systems have the advantage over air cooled systems of a much higher heat transfer rate and the fact that the heat can be transported a significant distance from the source. Liquid cooled avionics have their own challenges as well. The architecture of the components (cold plates, etc) used for extracting the heat from the electronics component must be optimized to perform consistently and reliably while maintaining the smallest footprint possible in the already crowded instrument panel.
2017-09-19
Technical Paper
2017-01-2019
Rakshath G Poojary, Mohammed Ali Jouhar, Abubakar K
Human Powered Helicopter which uses man power to operate. The main aim of this paper is to design commercially available vehicle for an Adventure Sporting under 5-6 lakh Indian Rupees. This structural design is extremely lightweight and strong. The product is designed in such a way that it can be easily assembled and dismantled for transportability and storage. We developed an aero-structural optimization scheme for rotor design, including an aerodynamic model with included ground effect prediction, finite-element analysis and integrated composite failure analysis, and a detailed weight estimation scheme. This was solely build on computer CAD models. This design includes the use of gear box to increase the output. The Aerodynamic analysis was done using CFD and BET (blade element theory-Bhramwell) in MATLAB.
2017-09-19
Technical Paper
2017-01-2022
Katherine Loundy, Louis Schaefer, Andrew Foran, Catherine Ninah, Khristopher Bandong, Robert Brown, Hunter Heston, John-Paul Steed, William Young, Mark Heinrich, Luis Rabelo
The future of human exploration in the solar system is contingent on the ability to exploit resources in-situ to produce mission consumables. Specifically, it has become clear that the success of a manned mission to Mars will likely depend on fuel components created on the Martian surface. While several architectures for an un-manned fuel production surface facility on Mars exist in theory, a simulation of the performance and operation of these architectures has not been created. In this paper, the framework describing a simulation of one such architecture is defined. Within this architecture, each component of the base is implemented as a state machine, with the ability to communicate with other base elements as well as a supervisor. An environment supervisor is also created which governs low level aspects of the simulation such as movement and resource distribution, in addition to higher-level aspects such as location selection with respect to operations specific behavior.
2017-09-19
Technical Paper
2017-01-2021
Numair Mazgaonkar, Andrew Stankovich
For large aerospace assemblies in finite element (FE) analysis problems, contact interaction between the surrounding bodies has to be established to simulate the load transferred between the components, like aircraft engine carrying bracket assemblies, spigots assemblies etc., and understand the effects of interaction between respective parts. In some cases, depending upon geometry of the assembly, the region of study may not be contact area but the stresses acting within the parts themselves. If there is no geometric or material non-linearity in such problems, a new contact formulation method known as Fast Contact can be used in these contact regions. In this method, contact non-linearity could be introduced to simulate the problem but friction between the contacting parts should not be present. Currently, there is a scope for applying this method for solving FE problems in the aerospace and rail industry.
2017-09-19
Technical Paper
2017-01-2028
Steven Nolan, Patrick Norman, Graeme Burt, Catherine Jones
Turbo-electric distributed propulsion (TeDP) for aircraft allows for the complete redesign of the airframe so that greater overall fuel and emissions benefits can be achieved. Whilst conventional electrical power systems may be used for smaller aircraft, much larger aircraft are likely to require the use of superconducting electrical power systems to enable the required whole system power density and efficiency levels to be achieved. The TeDP concept requires an effective electrical fault management and protection system. However, the fault response of a superconducting TeDP power system and its components has not been well studied to date, limiting the effective capture of associated protection requirements. For example, with superconducting systems it is the possible that a hotspot is formed on one of the components, such as a cable. This can result in one subsection, rather than all, of a cable quenching.
2017-09-19
Technical Paper
2017-01-2025
Eugenio Rodriguez
One of the most important activities associated with the Aerospace and Defense industry is maintenance. Maintainability procedures have a direct impact of safety and operational availability of the system. The processes or procedures used during maintenance activities, whether removing and replacing a component of a system, or even conducting troubleshooting, are generally discrete by design, and in most cases, a maintainer, or a field service representative (FSR), will follow a sequence of steps as part of a maintenance work package or work instruction. Depending on the system, those maintenance activities could be complex, requiring many steps to complete. In order to successfully accomplish complex tasks, generally, one of two possibilities need to exist, either the maintainer is well trained and experienced, or the maintenance work instructions are extremely detailed and precise; both of options can be time consuming and expensive to achieve.
2017-09-19
Technical Paper
2017-01-2024
Natasha L. Schatzman, Narayanan Komerath, Ethan A. Romander
The crossing event of the blades of a coaxial counter-rotating rotor is a potential source of noise and severe blade loads. Blade crossings occur several times each rotor revolution. Most of the radial variation in the flow field can be efficiently captured by stacking the results of a 2-D analysis using two airfoils approaching each other at the appropriate relative Mach number and separation distance. Previously, this phenomenon was analyzed by simulating two airfoils passing each other at specified speeds and vertical separation distances, using the compressible Navier-Stokes solver OVERFLOW. The simulations explored thickness, circulation, and compressible effects. Results revealed the complex nature of the aerodynamic and fluid dynamic impulses generated by blade-blade interactions, with implications for aeroelastic loads and aeroacoustic sources.
2017-09-19
Technical Paper
2017-01-2029
Thibaut BILLARD, Cedric Abadie, Bouazza Taghia
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
2017-01-2034
Bailey Hall, Benjamin Palmer, Tyler Milburn, Luis Herrera, Bang Tsao, Joseph Weimer
Future aircrafts will demand a significant amount of flight critical electrical power to drive the primary flight control surfaces. These electrical architectures will need to meet the load requirements and provide power to the flight critical buses at all times. For this to happen, a fast, resilient, and autonomous control scheme is needed. In this presentation, formal methods and linear temporal logic are used to develop a contactor control scheme to meet the given specifications of an electrical power system. The resulting control strategy is able to manage multiple contactors during different types of generator failures, while ensuring that flight critical buses maintain power. To verify the feasibility of the proposed control scheme, a real-time simulation platform is developed. Capability to test the control strategy, along with any future versions, was implemented with a microprocessor and analog/digital I/O’s (Hardware in the Loop).
Viewing 1 to 30 of 33298