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There are 12 papers published in subject: > since this site started. |
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1. The effect of ignition delay period on heat release of hydraulic free piston engine | |||
ZHANG Shuanlu,ZHAO Changlu,ZHAO Zhenfeng | |||
Dynamic and Electronic Engineering 19 December 2014 | |||
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Abstract:The special characteristic of hydraulic free piston diesel engine decides its differences in the aspects of piston displacement, velocity, and acceleration etc. These differences lead to more complex fluid flow, and particular intrinsic energy distribution in-cylinder. All these factors results in the differences of heat release. This article shows the heat release rate difference between the start cycles and the stable cycles and deems that the difference is related with the ignition delay period. From the expression equation of ignition delay period, the reason is ascribed to the boundary temperature. Based on selection of several cycles, we study the maximum value of heat release rate and pressure in-cylinder and it is obvious that the ignition delay period affects the heat release rate, pressure and BDC position. Finally, the corresponding optimum proposals for decreasing the difference are also represented. | |||
TO cite this article:ZHANG Shuanlu,ZHAO Changlu,ZHAO Zhenfeng. The effect of ignition delay period on heat release of hydraulic free piston engine[OL].[19 December 2014] http://en.paper.edu.cn/en_releasepaper/content/4624354 |
2. Methods to measure MEA status in PEM fuel cell and the effects of test conditions | |||
PEI Pucheng,XU Huachi,ZENG Xia | |||
Dynamic and Electronic Engineering 28 February 2013 | |||
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Abstract:To measure and monitor the membrane electrode assembly (MEA) status, the cyclic voltammetry (CV) and galvanostatic method are improved and compared. The electrochemical active surface area (EAS), double layer capacitance, H2 crossover current are measured by both the CV and galvanostatic method, and the cell resistance is also gained by the galvanostatic method. In the galvanostatic method, two or more constant currents are applied to a fuel cell stack, and the voltage responds between two electrodes of every cell are recorded and analyzed. Tests on a two-cell stack supplied with hydrogen in the anode and nitrogen in the cathode are carried out, and the influences of the temperature and relative humidity (RH) on the MEA parameters are investigated. Results show that with an increase in RH, both the double layer capacitance and EAS linear increase, while the hydrogen crossover current and cell resistance linear decrease; and with an increase in temperature, the hydrogen crossover current linear increases, cell resistance decreases, EAS and double layer capacitance show little change. The galvanostatic method shows a convenient technique to research the cell uniformity and the MEA lifetime in fuel cell stack. | |||
TO cite this article:PEI Pucheng,XU Huachi,ZENG Xia. Methods to measure MEA status in PEM fuel cell and the effects of test conditions[OL].[28 February 2013] http://en.paper.edu.cn/en_releasepaper/content/4524609 |
3. An investigation on anti-flooding of PEMFC with in-plate adverse-flow flow-field | |||
LI Pengcheng,PEI Pucheng,HE Yongling,ZHANG Hongfei | |||
Dynamic and Electronic Engineering 27 February 2013 | |||
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Abstract:The stoichiometric ratios and related regimes, which can promote anti-flooding of polymer electrolyte membrane fuel cell (PEMFC) with in-plate adverse-flow flow-field (IPAF), were investigated in this paper. Two flow combinations, which are the simple and complex adverse-flow between plates (ABP) that can be realized by IPAF, were employed to investigate. Constant stoichiometric ratios examination indicates that the complex ABP could improve anti-flooding of PEMFC better in the medium (greater than 200mA/cm2 and less than 1000mA/cm2) and high (greater than 1000mA/cm2) current densities than the simple ABP. More stoichiometric ratios were introduced to find the cathode critical stoichiometry. Under the condition of cathode critical stoichiometry, the maximal local relative humidity of both electrodes of complex ABP is equal to 100% and below while the anti-flooding of the cathode of simple ABP is not satisfactory in the medium and high current densities. Further study shows that the mechanism of fuel cell, which is the interdependence between the electrodes effect, can make significant contribution to anti-flooding. | |||
TO cite this article:LI Pengcheng,PEI Pucheng,HE Yongling, et al. An investigation on anti-flooding of PEMFC with in-plate adverse-flow flow-field[OL].[27 February 2013] http://en.paper.edu.cn/en_releasepaper/content/4524116 |
4. Design Optimization of Axisymmetric Endwall in Axial Compressor S-Shaped Duct | |||
Jin Donghai,Zhao Weiguang,Gui Xingmin | |||
Dynamic and Electronic Engineering 06 January 2013 | |||
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Abstract:This paper presents a numerical investigation on the potential aerodynamic benefits of using endwall contouring in a fairly aggressive duct with six struts based on the platform of the endwall design optimization. The platform was built with Adaptive Genetic Algorithm (AGA), Design of Experiments (DOE), Response Surface Methodology (RSM) based on the Artificial Neural Network (ANN) and a 3D Navier-Stokes solver. Visual analysis method based on DOE was used to define the design space and analyse the impact of the design parameters on the target function (response). Optimization of axisymmetric endwall contouring in the duct has been performed and evaluated. The objective was to minimize the total pressure loss. The optimal duct was found to reduce the hub corner separation and suppress the migration of the low momentum fluid. The axisymmetric endwall contouring was shown to suppress the separation and reduce the net duct loss by 22%. | |||
TO cite this article:Jin Donghai,Zhao Weiguang,Gui Xingmin. Design Optimization of Axisymmetric Endwall in Axial Compressor S-Shaped Duct[OL].[ 6 January 2013] http://en.paper.edu.cn/en_releasepaper/content/4510584 |
5. A novel experimental method to evaluate the impact of the volute's asymmetry on the performance of a high pressure ratio turbocharger compressor | |||
LIN Yun,ZHENG Xinqian,JIN Lei,TAMAKI Hideaki,KAWAKUBO Tomoki | |||
Dynamic and Electronic Engineering 02 March 2012 | |||
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Abstract:All components of a turbocharger compressor are axisymmetric except for the spiral-shaped, gas-collecting overhung volute. In this paper, a novel experimental method to evaluate the impact of the volute's asymmetry on centrifugal compressor performance is proposed and applied to a high pressure-ratio turbocharger compressor. This method can isolate the impact of the volute's asymmetry on the compressor performance for the first time. Experiments prove the considerable impact of the volute's asymmetry on the compressor performance, especially on the stability and efficiency. The impact of the volute's asymmetry on compressor stability correlates with rotational speed and therefore with pressure ratio; constricting the stable flow range by up to 47 percent and decreasing the maximum efficiency by 4.8 percent at design speed. The results provide evidence to exploit the potential of intrinsic non-axisymmetric flow induced by asymmetric volute to improve the performance of turbocharger compressor with high pressure ratio. | |||
TO cite this article:LIN Yun,ZHENG Xinqian,JIN Lei, et al. A novel experimental method to evaluate the impact of the volute's asymmetry on the performance of a high pressure ratio turbocharger compressor[OL].[ 2 March 2012] http://en.paper.edu.cn/en_releasepaper/content/4469699 |
6. Multiphase Pump Module for Subsea Deployment | |||
Hong-wu Zhu,Shou-sen Zhang,Kong Xiangling | |||
Dynamic and Electronic Engineering 21 May 2009 | |||
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Abstract:Offshore reserves——especially those discovered in deep water ——will be important in meeting future global oil demand .As oil companies step out into deeper waters, operators may discover that finding oil and gas is the easy part ——the real challenge lies in moving produced fluids from the reservoir to the processing facility .Multiphase subsea pumping represents a key development need .While multiphase pumping has been proven onshore ,operators have been hesitant to deploy this technology subsea due to its cost saving. This paper present the state of art in subsea multiphase boosting. This includes the subsea pump, subsea integration, power and control system, and intervention, installation. There are also several examples of subsea multiphase modules as production enabling equipment. Some experience and lessons will be addressed. Although multiphase pumps in most cases are used individually, they may be used in combination with other artificial lift technology like down hole pumps to offer integrated systems with premium reliability and economics. The last part of presentation will be related specifically to the prototype subsea multiphase pump designed by China University of Petroleum (beijing) , the motor-driven pump module is presented for vertical subsea installation on the sea bottom. Details of design like pump parameters, hydraulic parts(impellers, diffusers),cooling system ,bearings ,mixer will be presented. | |||
TO cite this article:Hong-wu Zhu,Shou-sen Zhang,Kong Xiangling. Multiphase Pump Module for Subsea Deployment[OL].[21 May 2009] http://en.paper.edu.cn/en_releasepaper/content/32389 |
7. Nonlinear Identification of Alstom Gasifier Based on Wiener Model | |||
Xin Wang,Wu Ke,Jianhong Lu,Wenguo Xiang | |||
Dynamic and Electronic Engineering 15 January 2009 | |||
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Abstract:In this work a nonlinear identification approach has been developed and implemented on Alstom gasifier with Wiener model. The linear element of the Wiener model is identified by a combined subspace state space method, which integrates MOESP (Multivariable Output-Error State Space) and N4SID (Numerical algorithms for subspace nstate space system identification) method in the estimation of system matrices. A single layer neural network is chosen as the nonlinearity of the model. The quadruple system matrices are identified firstly according to the given input-output sample data. Then an initial approximation of the static nonlinear part is determined with the output sequence of linear part. At last, all parameters of the wiener model are optimized by Levenberg-Marquardt algorithm, using the model parameters obtained formerly as the initial estimates. A nonlinear model of the plant at 0% load is adopted as a base model for estimation because it is the most difficult case to control among three operating conditions. The proposed model identification method was used to model Alstom gasifier with strong nonlinearity and multivariable couples, compared to a combined linear subspace identification method. The results demonstrate that the nonlinear identification proposed, which may be applied to nonlinear predictive control, behave better approximation than the linear method. | |||
TO cite this article:Xin Wang,Wu Ke,Jianhong Lu, et al. Nonlinear Identification of Alstom Gasifier Based on Wiener Model [OL].[15 January 2009] http://en.paper.edu.cn/en_releasepaper/content/27862 |
8. Influence Of Splitter Blades On The Total Flow Field Of A Low-Specific Centrifugal Pump | |||
Zhang Jin-feng,Yuan Shou-qi,Fu Yuedeng,Yuan Jianping | |||
Dynamic and Electronic Engineering 29 January 2008 | |||
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Abstract:Based on the low-specific speed centrifugal pump model of IS 50-32-160, two impellers are designed with and without splitter blades. The influence of adding splitter blades on the performance of the pump is studied by using numerical method. At first, the measurements of controlling simulation errors are presented, including the building of numerical and physical model, the determination of grid number, difference style and the Iterative residuals. The flow morphology shows that, when adding splitter blades to the impeller, the impeller periphery velocities and pressures become more homogeneous, which can reduce the pressure fluctuation at the area between impeller outlet and volute inlet; the lift head are evaluated at various flow rates, and the flow capacity in the volute is increased, which result in larger operating range; the flow in the part of volute diffuser become more uniform, and the use of it increase. By the performance forecasting, their performance curves are get, and the influence of splitters is presented: the curve of H-Q become more flat, the operating range is extended; the curve of η-Q become widen, and the maximum efficiency move to the larger flow rate, but not at the BEP; And the slope of the P-Q curve increase rapidly, which may result in electrical overload. | |||
TO cite this article:Zhang Jin-feng,Yuan Shou-qi,Fu Yuedeng, et al. Influence Of Splitter Blades On The Total Flow Field Of A Low-Specific Centrifugal Pump [OL].[29 January 2008] http://en.paper.edu.cn/en_releasepaper/content/18456 |
9. Analysis of the Piston Pin bore Friction Characteristic Based on the Lubrication Conditions | |||
Liu shiying,tian xiaoqing,wang zhiming | |||
Dynamic and Electronic Engineering 06 March 2007 | |||
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Abstract:The lubrication conditions of the pin bore affect the stress distributions and the piston durability. The maximum Von Mises stresses and the friction coefficients with different oil film thickness on the pin bore are analyzed. Under the constant oil film thickness, the maximum Von Mises stresses will enlarge along with the friction coefficients increase, but under the same friction coefficient conditions, the maximum Von Mises stress will reduce along with the oil film thickness increase. Increasing the lubrication ability and using the low friction coefficient material benefit the lubrication action and improve the parts durability. Increasing the friction coefficient increases the scuffing uncertainty factor. As a result, the fine cooperation between the gudgeon pin and the pin bore should be pursued during the product design for balancing the contact pressure, and keeping the good lubrication performance. | |||
TO cite this article:Liu shiying,tian xiaoqing,wang zhiming. Analysis of the Piston Pin bore Friction Characteristic Based on the Lubrication Conditions[OL].[ 6 March 2007] http://en.paper.edu.cn/en_releasepaper/content/11285 |
10. Study of Spark Ignition Engine Fueled with Methanol/Gasoline Fuel Blends | |||
Liu Shenghua,Hu Tiegang,Liang Xiaoqiang,Zhou Longbao | |||
Dynamic and Electronic Engineering 06 November 2006 | |||
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Abstract: A 3-cylinder PFI engine was adopted to study engine power, torque, fuel economy, emissions including regulated and non-regulated pollutants and cold start performance with the fuel of low fraction methanol in gasoline. Without any retrofit of the engine, experiments show that the engine power and torque will decrease with the increase fraction of methanol in the fuel blends under WOT conditions. However, if spark ignition timing is advanced, the engine power and torque can be improved under WOT operating conditions. Engine thermal efficiency is thus improved in almost all operating conditions. Engine combustion analyses show that the fast burning phase becomes shorter, however, the flame development phase is a little delay. When methanol/gasoline fuel blends being used, the engine emissions of CO and HC decrease, NOx changes little prior to three-way catalytic converter (TWC). After TWC, the conversion efficiencies of HC, CO and NOx are better. | |||
TO cite this article:Liu Shenghua,Hu Tiegang,Liang Xiaoqiang, et al. Study of Spark Ignition Engine Fueled with Methanol/Gasoline Fuel Blends[OL].[ 6 November 2006] http://en.paper.edu.cn/en_releasepaper/content/9295 |
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