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A New Positioning Device Designed for Aircraft Automated Alignment System

Shanghai Jiao Tong University-Jie Huang, Long Yu, Yuhan Wang
Shanghai Top NC Tech Co Ltd-Yilian Zhang
Published 2019-09-16 by SAE International in United States
Accurate and fast positioning of large aircraft component is of great importance for Automated Alignment System. The Ball joint is a widely-used mechanical device connecting the aircraft component and positioners. However, there are some shortcomings for the device in man-machine engineering, such as the entry state of the ball-head still needs to be confirmed by the workers and then switched to the locking state manually. To solve above problems, a new positioning mechanism is present in this paper, which consists of a ball-head and a ball-socket. The new device is equipped with a monocular vision system, in which a calibrated industrial camera is used to collect the images of the ball-head. And then, the 3-D coordinate of the ball-head center is calculated by a designed algorithm, guiding the positioner to capture the ball-head. Once the ball-head gets into the ball-socket, the pneumatic system will drive the pistons to move to the specified location. Meanwhile, the amount of compression of a set of springs has changed, so the steel balls are compelled to compress, contact or…
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The Effect of Crosswinds on Icing at Turbofan Engine Inlet

Shanghai Jiao Tong University-Qian Yang, Zhiqiang Guo, Mei Zheng, Wei Dong
Published 2019-06-10 by SAE International in United States
Ice accretion at engine inlet has a dangerous effect on the inlet airflow and shed ice would be ingested into the engine and cause compressor blades damage, and even combustors flame out. In order to analyze the effect of crosswinds on icing at turbofan engine inlet, a complete icing analysis method, which is based on the Messinger model and takes the influence of runback water into consideration, is constructed. The runback water is considered laminar flow and the flow direction is dominated by the bottom flow of air. The supercooled water droplets impingement, ice accretion and runback water characteristics and inlet distortion with and without ice were investigated at crosswinds speed of 15, 20, 25, 30 kt. The variation of local water collection coefficient β is unchanged at crosswind conditions, but the location of the maximum value and non-dimensional impact limits change with the crosswind, which move backward along the outer edge on the windward, and move along the inner edge on the leeward. The ice thickness on windward surface increases slightly near the stagnation…
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Heat Transfer Characteristics of Gas Cooler in a CO2 Automobile Heat Pump System

Shanghai Jiao Tong University-Dandong Wang, Jun-ye Shi, Binbin Yu, Jiangping Chen
Published 2019-04-02 by SAE International in United States
An automobile heat pump system with conventional refrigerant (HFC-134a or HFO-1234yf) suffers significantly diminishment of heating capacity and system efficiency as the ambient temperature decreases. Natural refrigerant CO2 (GWP = 1) is considered as a promising alternative to HFC-134a in automobile air conditioning (MAC) applications with environmentally friendly advantage. In addition, CO2 automobile heat pump system is a promising heat pump technology for EVs with great heating advantages in a cold climate. This study aims to investigate the supercritical heat transfer characteristics of a compact micro-channel gas cooler applied in an automobile CO2 heat pump system. A simulation model of automobile gas cooler was developed by using segment-by-segment method, and validated by experimental results from Series Gas cooler (SGC) and One Gas cooler (OGC) CO2 heat pump systems. The error of heating capacity between calculated results and experimental results was less than 7%. Using this model, the air and refrigerant temperature distribution as well as the heat transfer coefficient along the refrigerant flow path under the condition of -20 °C air inlet temperature and 9…
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Effect of Injection Pressure on Nozzle Internal Flow and Jet Breakup under Sub-Cooled and Flash Boiling Test Conditions

Shanghai Jiao Tong University-Shangze Yang, Xuesong Li, Min Xu
UM-SJTU JI, Shanghai Jiao Tong University-David L.S. Hung
Published 2019-04-02 by SAE International in United States
Injection pressure plays a vital role in spray break-up and atomization. High spray injection pressure is usually adopted to optimize the spray atomization in gasoline direct injection fuel system. However, higher injection pressure also leads to engine emission problem related to wall wetting. To solve this problem, researchers are trying to use flash boiling method to control the spray atomization process under lower injection test conditions. However, the effect of injection pressure on the spray atomization under flash boiling test condition has not been adequately investigated yet. In this study, quantitative study of internal flow and near nozzle spray breakup were carried out based on a two-dimensional transparent nozzle via microscopic imaging and phase Doppler interferometery. N-hexane was chosen as test fluid with different injection pressure conditions. Fuel temperature varied from 112°C to 148°C, which covered a wide range of superheated conditions. Injection pressure was varied from 3MPa to 5MPa. The effect of injection pressures on nozzle internal flow and jet breakup is analyzed experimentally. As a result, decreasing injection pressure leads to smaller droplet…
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Energy Management Optimization for Plug-In Hybrid Electric Vehicles Based on Real-World Driving Data

Shanghai Jiao Tong University-Hongpu Xia, Tie Li, Bin Wang, Pengfei He, Yuxin Chen
Published 2019-04-02 by SAE International in United States
Excellent energy consumption performance of a plug-in hybrid electric vehicle (PHEV) is usually attributed to its hybrid drive mode. However, the factors including vehicle performance, driver behavior and traffic status have been shown to cause unsatisfactory performance. This phenomenon leads to a necessity of study on energy consumption control strategies under real-world driving conditions. This paper proposes a new approach for energy management optimization of plug-in hybrid electric vehicles based on real-world driving data for two purposes. One is for improving the energy consumption of PHEV under real-world driving conditions and the other is for reducing the computational complexity of optimization methods in simulation models. In this process, the paper collected real-world driving record data from 180 drivers within 6 months. Then the principal component analysis (PCA) was employed to extract and define the hidden factors from the initial real-world driving data. The K-means clustering method was employed to evaluate the sensitivity of new factors to the energy consumption of PHEV, in which the sensitivity was defined through the Pearson correlation coefficient and covariance. Moreover,…
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Preliminary Testing of n-Butanol HCCI on High Compression Ratio Diesel Engines

Shanghai Jiao Tong University-Tie Li
University of Windsor-Simon Leblanc, Prasad Divekar, Xiaoye Han, Jimi Tjong, Ming Zheng
Published 2019-04-02 by SAE International in United States
The control of combustion phasing in homogeneous charge compression ignition (HCCI) combustion is investigated with neat n-butanol in this work. HCCI is a commonly researched combustion mode, owing to its improved thermal efficiency over conventional gasoline combustion, as well as its lower nitrogen oxide (NOx) and particulate matter emissions compared to those of diesel combustion. Despite these advantages, HCCI lacks successful widespread implementation with conventional fuels, primarily due to the lack of effective combustion phasing control. In this preliminary study, chemical kinetic simulations are conducted to study the auto-ignition characteristics of n-butanol under varied background pressures, temperatures, and dilution levels using established mechanisms in CHEMKIN software. Increasing the pressure or temperature lead to a shorter ignition delay, whereas increasing the dilution by the application of exhaust gas recirculation (EGR) leads to a longer ignition delay. These ignition delay simulation results are used as a guide for the experimental study of n-butanol HCCI combustion on engine tests. Experiments are conducted near engine mid-load (~7 bar IMEP) on two engines with high compression ratios (i.e. 16.2:1 and…
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Characteristics of Impinging Spray and Corresponding Fuel Film under Different Injection and Ambient Pressure

Shanghai Jiao Tong University-Di Xiao, Xuesong Li, Min Xu
UM-SJTU JI, Shanghai Jiao Tong University-David L.S. Hung
Published 2019-04-02 by SAE International in United States
It has been found that the spray impingement on piston for SIDI engines significantly influences engine emission and combustion efficiency. Fuel film sticking on the wall will dramatically cause deterioration of engine friction performance, incomplete combustion, and substantial cycle-to-cycle variations. When increasing the injection pressure, these effects are more pronounce. Besides, the ambient pressure also plays an important role on the spray structure and influences the footprint of impinging spray on the plate. However, the dynamic behavior of impinging spray and corresponding film was not investigated thoroughly in previous literature. In this study, simultaneous measurements of macroscopic structure (side view) and its corresponding footprint (bottom view) of impinging spray was conducted using a single-hole, prototype injector in a constant volume chamber. A high pressure supply system was employed to change the injection pressure, and the ambient pressure was controlled by a vacuum pump. The macroscopic spray structure was captured by high-speed Mie-scattering imaging, while for the film measurement, laser induced fluorescence (LIF) technique was used to measure the spatial distribution and temporal development of the…
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A Study of Energy Enhanced Multi-Spark Discharge Ignition in a Constant-Volume Combustion Chamber

Shanghai Jiao Tong University-Chang ye
Shanghai Jiao Tong Univ-Min Xu
Published 2019-04-02 by SAE International in United States
Multi-spark discharge (MSD) ignition is widely used in high-speed internal combustion engines such as racing cars, motorcycles and outboard motors in attempts to achieve multiple sparks during each ignition. In contrast to transistor coil ignition (TCI) system, MSD system can be greatly shortened the charging time in a very short time. However, when the engine speed becomes higher, the ignition will be faster, electrical energy stored in the ignition system will certainly become less, especially for MSD system. Once the energy released into the spark plug gap can’t be guaranteed sufficiently, ignition will become more difficult, and it will get worse in some harsh environment such as strong turbulence or lean fuel conditions. With these circumstances, the risks of misfire and partial combustion will increase, which can deteriorate the power outputs and exhaust emissions of internal combustion engine. Therefore, in order to extend the ignitability limit and reduce the combustion variation without sacrificing spark energy for high speed engines, an energy enhanced multi-spark discharge (EEMSD) ignition system is developed in this study. The principle of…
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Study of Flash Boiling Spray Combustion in a Spark Ignition Direct Injection Optical Engine Using Digital Image Processing Diagnostics

Shanghai Jiao Tong University-Zhe Sun, Zhen Ma, Xuesong Li, Min Xu
Published 2019-04-02 by SAE International in United States
Flash boiling spray has been proven to be a useful method in providing finer fuel droplet and stronger evaporation in favor of creating a homogeneous fuel-air mixture. Combustion characteristics of flash boiling spray are thus valuable to be investigated systematically for aiding the development of efficient internal combustion system. An experimental study of flash boiling spray combustion in a SIDI optical engine under early injection has been conducted. The fuel, Iso-octane, was used across all tests. Three fuel spray conditions experimented in the study: normal liquid, transitional flash boiling and flare flash boiling sprays, within each case that Pa/Ps ratio was set in (>1), (0.3~1), and (<0.3) respectively. A small quartz insert on the piston enables optical access for observing combustion process; non-intrusive measurements on flame radicals has been carried out using a high-speed color camera. With the use of digital image processing and color analysis, the imaging system was turned into an abstract multi-spectral system to determine the characteristics of flame emission. In addition, the near infrared region was capable of being discriminated from…
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Robust Speed Synchronization Control for an Integrated Motor-Transmission Powertrain System with Feedback Delay

Shanghai Jiao Tong University-Jianfeng Huang, Jianlong Zhang, Chengliang Yin
Published 2019-04-02 by SAE International in United States
Motor speed synchronization is important in gear shifting of emerging clutchless automated manual transmissions for battery electric vehicles (BEV) and other kinds of parallel shaft-based powertrains for hybrid electric vehicles (HEV). Difficulties of the problem mainly come from random delay induced by network communication and unknown load torques from air drag, oil drag, and friction torques, etc. To deal with these two factors, this paper proposes a robust speed synchronization controller based on act-and-wait control and disturbance observer. The former is a kind of periodical controller specially for regulating problems with feedback delay while the latter is a technique for active disturbance rejection. Firstly, the dynamic model of the motor shaft is formulated, and the system parameters are offline identified. The speed tracking problem is then transformed into a regulating one. The act-and-wait control law for the nominal model is proposed regarding the new model after transformation. Determination of controller parameters and their relationship with the speed synchronizing process are discussed. After derivation of the nominal controller, a time-domain disturbance observer is integrated to enhance…
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