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Unsteady Numerical Simulation of Steam-Solid Two-Phase Flow in the Governing Stage of a Steam Turbine

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Journal of Thermal Science 2009年第4期18卷 313-320页

作者： Yufeng Li Peigang Yan Wanjin Han School of Energy Science & Engineering Harbin Institute of Technology Harbin Heilongjiang 150001 China harbin Turbine company limited Harbin Heilongjiang 150046 China

Solid particle erosion (SPE) in an ultra-supercritical steam turbine control stage with block configuration is investigatednumerically, based on the finite volume method and the fluid-particle coupling solver. We apply the particlediscrete phase model to model the solid particles flow, and use the Euler conservation equations to solve thecontinuous phase. The investigation is focused on the influence of the solid particle parameters (such as particlediameter, particle velocity and particle trajectory) on the erosion rate of the stator and rotor blade surface in unsteadycondition. The distributions of the highly eroded zone on the stator and rotor blade surfaces are shown anddiscussed in detail according to the mechanism of solid particle/blade wall interaction. We obtain that the erosionrate of the vane blade is sensitive to the fluctuation of the potential flow field, and the smaller particle has agreater impact on the erosion distribution of rotor blade. The erosion rate does not entirely depend on the diametersize of the solid particle.

关键词： steam turbine unsteady numerical simulation solid particle erosion blade

Impact time control using biased proportional navigation for missiles with varying velocity

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Chinese Journal of Aeronautics 2020年第3期33卷 956-964页

作者： Guoxin SUN Qiuqiu WEN Zhiqiang XU Qunli XIA School of Aerospace Beijing Institute of TechnologyBeijing 100081China harbin Jiancheng Industry company limited Harbin 150030China

A feasible guidance scheme with impact time constraint is proposed for attacking a stationary target by missiles with time-varying *** main idea is to replace the constant velocity with the future mean velocity;therefore, the existing time-to-go estimation algorithm of the proportional navigation guidance law can be improved to adapt to varying *** order to obtain the prediction of the velocity profile, the velocity differential equation to the downrange is derived, which can be numerically integrated between the current downrange and the target position by the on-board ***, a third-order polynomial is introduced to fit the velocity profile in order to calculate the future mean *** the beginning of each guidance loop, the future mean velocity is predicted and the time-to-go information is updated, based on which a novel biased proportional navigation guidance law is established to achieve the impact time ***,numerical simulation results verified the effectiveness of the time-to-go estimation algorithm and the proposed law.

关键词： Guidance Homing missiles Impact time Proportional navigation guidance Time-varying velocity

Electrochemical impedance spectra of V_2O_5 xerogel films with intercalation of lithium ion

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Journal of Central South University of Technology 2005年第3期12卷 309-314页

作者：张勇刘玉文程玉山胡信国 Department of Applied Chemistry Harbin Institute of TechnologyHarbin 150001ChinaJiangmen JJJ Battery Company LimitedJiangmen 529000China Jiangmen JJJ Battery company limited Jiangmen 529000China Department of Applied Chemistry Harbin Institute of TechnologyHarbin 150001China

Vanadium pentoxide xerogel films used for lithium rechargeable batteries were prepared from crystalline c-V2O5 by melt quenching method,then the electrochemical process of lithium intercalation into vanadium pentoxide xerogel films was simulated with an equivalent circuit model, which was derived from the mechanism of electrode reactions. Measured electrochemical impedance spectra at various electrode potentials were analyzed by using the complex non-linear least-squares fitting method. The results show that impedance spectra consist of 2 high-to- medium frequency depressed arcs and a low frequency straight line. The high frequency arc is attributed to the absorption reaction of lithium ions into the oxide film, the medium frequency arc is attributed to the charge transfer reaction at the vanadium oxide/electrolyte interface and the low frequency is characterized by a straight line with a phase angle of 45° corresponding to the diffusion of lithium ion through vanadium oxide phase. The experimental and calculated results are compared and discussed focusing on the electrochemical performance and the state of charge of the electrode. Moreover, the high consistence of the fitted values of the model to the experimental data indicates that this mathematical model does give a satisfying description of the intercalation process of vanadium pentoxide xerogel films.

关键词： vanadium pentoxide xerogel films electrochemical impedance spectra equivalent circuit melt quenching method lithium rechargeable batteries

Characteristic of laser-MIG hybrid welding with filling additional cold wire for aluminum alloy

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China Welding 2018年第3期27卷 35-41页

作者： Chang Yunfeng Lei Zhen Wang Xuyou Teng Bin Yang Haifeng harbin Welding Institute limited company Harbin 150028China

The weld appearance, deposition rate, welding efficiency, stability of arc, laser keyhole characteristic, and weld property were studied by using a novel laser-MIG hybrid welding process with filling wire of aluminum alloy. The results were also compared with those by conventional laser-MIG hybrid welding process. It was found that with the suitable process parameters this novel welding process for aluminum alloy was stable and final weld bead had fine appearance. Compared to conventional laser-MIG hybrid welding process, during this novel welding process the stability of arc, the laser keyhole characteristic and the weld property were similar, while the keyhole cycle frequency and keyhole opening area had differences of 1.23% and 15.34%, respectively, and the welding efficiency increased by about 31% without increasing heat input.

关键词： aluminum alloy hybrid welding with filling wire deposition rate laser keyhole

Experimental Investigation for Co-Combustion Characteristics of Semi-Coke and Bituminous Coal in a 3 MWth Tangential Combustion Facility

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Journal of Thermal Science 2020年第6期29卷 1655-1662页

作者： GUAN Jingyu YU Qiang SUN Rui SHEN Tao WANG Minghao YAN Yanfei SONG Xin School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China State Key Laboratory of Efficient and Clean Coal-Fired Utility Boilers Harbin Boiler Company LimitedHarbin 150046China

An experimental investigation was conducted in a 3 MW pilot-scale tangential combustion facility to explore the co-combustion characteristics of bituminous coal mixed with *** thermal gravimetric analyzer(TGA)was used to obtained fuel thermal *** results presented effects of semi-coke blending ratio(BR)on average furnace temperature,ignition temperature,NO emission and combustion *** excess air coefficient in main combustion sections and outlet were fixed at 0.85 and 1.2 while BR increased from 0%to 50 wt.%.The temperature profiles of combustion decreases along the height of furnace while average furnace temperature fluctuates slightly with an increasing *** concentration of NO has an increasing tendency with the increasing of *** ignition temperature obtained from TGA measurement agreed well with experiment *** addition,combustion efficiency was not sensitive to BR and decreased slightly with the increasing BR.

关键词： tangential combustion semi-coke blending ratio combustion characteristics experimental investigation

Studies of flow field characteristics during the impact of a gaseous jet on liquid–water column

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Chinese Physics B 2019年第6期28卷 293-301页

作者： Jian Wang Wen-Jun Ruan Hao Wang Li-Li Zhang School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing 210094China harbin Jian Cheng Bloc limited company Harbin 150030China

Both experimental and numerical studies were presented on the flow field characteristics in the process of gaseous jet impinging on liquid–water column. The effects of the impinging process on the working performance of rocket engine were also analyzed. The experimental results showed that the liquid–water had better flame and smoke dissipation effect in the process of gaseous jet impinging on liquid–water column. However, the interaction between the gaseous jet and the liquid–water column resulted in two pressure oscillations with large amplitude appearing in the combustion chamber of the rocket engine with instantaneous pressure increased by 17.73% and 17.93%, respectively. To analyze the phenomena, a new computational method was proposed by coupling the governing equations of the MIXTURE model with the phase change equations of water and the combustion equation of propellant. Numerical simulations were carried out on the generation of gas, the accelerate gas flow, and the mutual interaction between gaseous jet and liquid–water *** simulations showed that a cavity would be formed in the liquid–water column when gaseous jet impinged on the liquid–water column. The development speed of the cavity increased obviously after each pressure oscillation. In the initial stage of impingement, the gaseous jet was blocked due to the inertia effect of high-density water, and a large amount of gas gathered in the area between the nozzle throat and the gas–liquid interface. The shock wave was formed in the nozzle expansion section. Under the dual action of the reverse pressure wave and the continuously ejected high-temperature gas upstream, the shock wave moved repeatedly in the nozzle expansion section, which led to the flow of gas in the combustion chamber being blocked, released, re-blocked, and re-released. This was also the main reason for the pressure oscillations in the combustion chamber.

关键词： gaseous jet liquid–water column pressure oscillations shock wave

Super-resolution reconstruction of astronomical images using time-scale adaptive normalized convolution

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Chinese Journal of Aeronautics 2018年第8期31卷 1752-1763页

作者： Rui GUO Xiaoping SHI Yi ZHU Ting YU Control and Simulation Center Harbin Institute of Technology Harbin 150080 China Tianjin Branch of China Petroleum Pipeline Engineering company limited Tianjin 300457 China

In this work, we describe a new multiframe Super-Resolution（SR） framework based on time-scale adaptive Normalized Convolution（NC）, and apply it to astronomical images. The method mainly uses the conceptual basis of NC where each neighborhood of a signal is expressed in terms of the corresponding subspace expanded by the chosen polynomial basis function. Instead of the conventional NC, the introduced spatially adaptive filtering kernel is utilized as the applicability function of shape-adaptive NC, which fits the local image structure information including shape and orientation. This makes it possible to obtain image patches with the same modality,which are collected for polynomial expansion to maximize the signal-to-noise ratio and suppress aliasing artifacts across lines and edges. The robust signal certainty takes the confidence value at each point into account before a local polynomial expansion to minimize the influence of ***, the temporal scale applicability is considered to omit accurate motion estimation since it is easy to result in annoying registration errors in real astronomical applications. Excellent SR reconstruction capability of the time-scale adaptive NC is demonstrated through fundamental experiments on both synthetic images and real astronomical images when compared with other SR reconstruction methods.

关键词： Astronomical image processing Motion estimation Normalized Convolution(NC) Polynomial expansion Signal-to-noise ratio Super-Resolution (SR)reconstruction

A Method of Purification of Bovine Colostrum sIgA

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Journal of Northeast Agricultural University(English Edition) 2008年第2期15卷 23-25页

作者： LIU Xiaofei GAO Xuejun YAO Yonghao ZHOU Shenghua Key Laboratory of dairy Science of Ministry of Education Northeast Agricultural University Harbin 150030 China harbin kanpure dairy limited company Harbin 150000 China College of Veterinary Medicine Northeast Agricultural University Harbin 150030 China

sIgA in bovine colostrum was purified by ultrafiltration and enzymolysis methods in this experiment, and the prepared substance was detected by Western Blot. The purity and yield were up to 73.6% and 65.2%, respective... 详细信息

关键词： bovine colostrum sIgA purification enzymolysis ultrafiltration

Cr,Er：Y2.93Sc1.43Ga3.64O12 Laser Giant Pulse Generation at 2.79 μm Using Electro-Optic Q-Switch

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Chinese Physics Letters 2008年第4期25卷 1293-1296页

作者：刘金生刘京郊 Institute of Opto-electronics Harbin Institute of Technology Harbin 150001 Institute of North Electronic Equipment Beijing 10083 Currently with the Accueo company limited Beijing 100102

We present an electro-optically Q-switched 2. 79 μm Cr, Er：Y2.93 Sc1.43 Ga3.64 O12 laser using LiNbO3 Pockels cell and undoped Y3Al15O12 plate polarizer. The optimal delay for triggering the Q-switch with respect to the peak of waveform of the flashlamp is found to be about 120μs. The minimum pump threshold of 13.2J is realized using the output coupler of reflectivity 74%. The maximum outputs of 72.3mJ at 3Hz and 35.4mJ at 10Hz repetition rates are obtained. The minimum pulse width is measured to be 31.9 ns. The far-field divergence angle of the laser beam is about 8.8 mrad. The influence of repetition rates on the output energy is also discussed.

关键词： supernova explosion proto-neutron star shock wave