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Wang X.,CAS Institute of Process Engineering | Li K.,China Automotive Technology and Research Center | Su W.,Tianjin University
Experimental Thermal and Fluid Science | Year: 2012

The internal flow characteristics of a single-hole diesel nozzle under the real fuel injection condition have been intensively explored through a combination of experimental measurements and numerical modeling with a two fluid approach. The pressure fluctuations upstream the nozzle hole, the evolution of cavitation content inside the nozzle hole and the mean dynamic behavior of local bubbles have been particularly analyzed. The results indicate that the pressure close to the inlet of nozzle hole fluctuates more drastically as the average injection pressure increases, and the internal flow of nozzle hole corresponding to the coexistence of pressure fluctuations and cavitation is inherently unsteady and complicated. It is of interest that the cavitation content and the liquid mass flow rate inside the nozzle hole indicate a close association with the variations of pressure change rate and pressure at the nozzle inlet, respectively, and as the spatial location of bubbles inside the nozzle hole obviously varies the mean dynamic behavior of these bubbles show distinct responses to upstream pressure fluctuations. © 2012 Elsevier Inc. Source

Yu G.X.,China Automotive Technology and Research Center
Applied Mechanics and Materials | Year: 2014

The paper check external projections of the SUV to provide measurement methods, design methods and design basis,research how to meet the regulations beyond to the example to analysis the request of GB basing on GB11566-2009 «External projections for passenger car». © (2014) Trans Tech Publications, Switzerland. Source

Xu D.,Hunan University | Yu Q.,China Automotive Technology and Research Center | Zhou J.,Hunan University | Bishop S.R.,University College London
Journal of Sound and Vibration | Year: 2013

This paper presents a nonlinear magnetic low-frequency vibration isolator designed with the characteristic of quasi-zero stiffness (QZS). An approximate expression of the magnet repulsive force is proposed and a unique analytical relationship between the stiffness of vertical spring and initial gap settings of the magnet springs is derived for the QZS system. Based on the harmonic balance (HB) method, the force transmissibility is formulated and the jumping frequencies, effect of excitation force and damping ratio are discussed for characteristic analysis. An experimental prototype is developed and tested. The performance of the QZS system is verified through a series of experimental studies showing that the new model greatly outperforms standard linear isolation systems especially in low-frequency domain. The tuning techniques for adapting to the change of loading mass and adjusting the QZS property in practice are also addressed. © 2013 Elsevier Ltd. All rights reserved. Source

Li L.,University of Shanghai for Science and Technology | Li F.,China Automotive Technology and Research Center | Zhang Z.,Harbin Institute of Technology | Zhang Z.,University of Victoria | Xu J.,Harbin Institute of Technology
Signal Processing | Year: 2013

This paper is devoted to the H∞ filtering problem for network-based discrete-time systems subject to network communication constraints. The objective is to design a network-based full-order or reduced-order filter, such that the resulting filtering error system is mean-square stable, while a prescribed H∞ disturbance attenuation levels is satisfied. A Markov chain is used to describe the network-induced delays. Then, a mode-dependent linear filter is considered, whose parameters are scheduled by the network-induced delays. By converting the partially unknown transition probability matrix to be a known convex description, and using the slack matrix approach, a new less conservative mode-dependent sufficient condition for the existence of the desired filter is derived to guarantee that the filtering error system is stochastically stable while satisfying a given H∞ performance. Based on this condition, the filter design method is proposed, and by solving some convex linear matrix inequalities, the explicit of the desired filer gain matrices is also given. Finally, a practical example is included to illustrate the effectiveness of the proposed method. © 2012 Elsevier B.V. All rights reserved. Source

Feng X.,Tsinghua University | Feng X.,University of Michigan | Sun J.,University of Michigan | Ouyang M.,Tsinghua University | And 4 more authors.
Journal of Power Sources | Year: 2015

This paper investigates the mechanisms of penetration induced thermal runaway (TR) propagation process within a large format lithium ion battery pack. A 6-battery module is built with 47 thermocouples installed at critical positions to record the temperature profiles. The first battery of the module is penetrated to trigger a TR propagation process. The temperature responses, the voltage responses and the heat transfer through different paths are analyzed and discussed to characterize the underlying physical behavior. The temperature responses show that: 1) Compared with the results of TR tests using accelerating rate calorimetry (ARC) with uniform heating, a lower onset temperature and a shorter TR triggering time are observed in a penetration induced TR propagation test due to side heating. 2) The maximum temperature difference within a battery can be as high as 791.8 °C in a penetration induced TR propagation test. The voltage responses have a 5-stage feature, indicating that the TR happens in sequence for the two pouch cells packed inside a battery. The heat transfer analysis shows that: 1) 12% of the total heat released in TR of a battery is enough to trigger the adjacent battery to TR. 2) The heat transferred through the pole connector is only about 1/10 of that through the battery shell. 3) The fire has little influence on the TR propagation, but may cause significant damage on the accessories located above the battery. The results can enhance our understandings of the mechanisms of TR propagation, and provide important guidelines in pack design for large format lithium ion battery. © 2014 Elsevier B.V. Source

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