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Simulation of mass and heat transfer in liquid hydrogen tanks during pressurizing

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Chinese journal of Aeronautics 2019年第9期32卷 2068-2084页

作者： jiachao LI Guozhu liang School of Astronautics Beihang University

In order to accurately predict the heat and mass transfer behaviors and analyze key factors affecting pressurization process in the hydrogen tank, a comprehensive 2 D axial symmetry Volume-Of-Fluid(VOF) model is established by Computational Fluid Dynamics(CFD) *** effects of phase change, turbulence and mass diffusion are included in the model and relationships between physical properties and temperature are also comprehensively considered. The phase change model is based on Hertz-Knudsen equation and the mass transfer time relaxation factor is determined by the NASA’s experimental data. The mass diffusion model is included in gaseous helium pressurizing. The key factors including the inlet temperature, inlet mass flow rate, injector types and pressurizing gas kinds are quantitatively analyzed. Compared with the experiment, the simulation results show that the deviation of pressurizing gas mass consumption, condensing mass and ullage temperature are 3.0%, 7.5% and 4.0% respectively. The temperature stratification is existed along the axial direction in the surface liquid region and the ullage region, and the bulk liquid is in subcooled state during pressurizing. The location of phase change mainly appears near the vapor–liquid interface, and the mass transfer expressing as condensation or vaporization is mainly determined by the heat convection and molecular concentration near the vapor–liquid *** key factors show that increasing the inlet temperature and inlet mass flow rate could shorten the pressurizing time interval and save the pressurizing gas mass. The proportion of the total energy addition of the tank absorbed by the ullage region, the liquid region and the tank wall respectively is greatly influenced by the injector types and more heat transferred into the ullage would result in a faster pressure rising rate. Gaseous hydrogen pressurization has a higher efficiency than gaseous helium pressurization. The simulation results presented in this

关键词： CFD Condensation Cryogenics Evaporation Phase change Pressurization

Mobilization of arsenic from contaminated sediment by anionic and nonionic surfactants

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journal of Environmental Sciences 2017年第6期29卷 281-289页

作者： Chuan liang Xianjia Peng Beijing Key Laboratory of Industrial Wastewater Treatment and Reuse Research Center for Eco-Environmental SciencesChinese Academy of SciencesBelting 100085China Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

The increasing manufacture of surfactants and their wide application in industry, agriculture and household detergents have resulted in large amounts of surfactant residuals being discharged into water and distributed into sediment. Surfactants have the potential to enhance arsenic mobility, leading to risks to the environment and even human beings. In this study, batch and column experiments were conducted to investigate arsenic mobilization from contaminated sediment by the commercial anionic surfactants sodium dodecylbenzenesulfonate （SDBS）, sodium dodecyi sulfate （SDS）, sodium laureth sulfate （AES） and nonionic surfactants phenyl-polyethylene glycol （Triton X-100） and polyethylene glycol sorbitan monooleate （Tween-80）. The ability of surfactants to mobilize arsenic followed the order AES 〉 SDBS 〉 SDS = Triton X-100 〉 Tween 80. Arsenic mobilization by AES and Triton X-100 increased greatly with the increase of surfactant concentration and pH, while arsenic release by SDBS, SDS and Tween-80 slightly increased. The divalent ion Ca2＋ caused greater reduction of arsenic mobilization than Na＋. Sequential extraction experiments showed that the main fraction of arsenic mobilized was the specifically adsorbed fraction. Solid phase extraction showed that arsenate （As（V）） was the main species mobilized by surfactants, accounting for 65.05%-77.68% of the total mobilized arsenic. The mobilization of arsenic was positively correlated with the mobilization of iron species. The main fraction of mobilized arsenic was the dissolved fraction, accounting for 70% of total mobilized arsenic.

关键词： Surfactants Arsenic Iron Sediment Mobilization

Inhibitory effects of novel green inhibitors on gas hydrate formation

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Chinese journal of Chemical Engineering 2019年第9期27卷 2107-2117页

作者： Cuiping Tang Deqing liang Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China Key Laboratory of Gas Hydrate Chinese Academy of SciencesGuangzhou 510640China

Natural gas hydrates easily form in pipelines,causing potential safety issues during oil and gas production and *** gas hydrate inhibitors is one of the most effective methods for preventing gas hydrate formation or ***,some thermodynamic hydrate inhibitors are toxic and harmful to the environment,whereas degradation of kinetic inhibitors is ***,environmentally friendly and easily biodegradable novel green inhibitors have been proposed and *** paper provides a short but systematic review of the inhibitory performance of amino acids,antifreeze proteins,and ionic *** different hydrate formation systems,the influences of the inhibitor type,structure,and concentration on the inhibitory effects are *** mechanism of green inhibitors as kinetic inhibitors is also *** progress described here will facilitate further developments of such green inhibitors for gas hydrate formation.

关键词： Gas hydrate Inhibition Green inhibitors Kinetic inhibitors Thermodynamic inhibitors

A fault tolerant model for multi-sensor measurement

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Chinese journal of Aeronautics 2015年第3期28卷 874-882页

作者： Li liang Shi Wei Information and Ecommerce Institute University of Electronic Science & Technology of China China Gas Turbine Establishment

Abstract Multisensor systems are very powerful in the complex environments. The cointegration theory and the vector error correction model, the statistic methods which widely applied in economic analysis, are utilized to create a fitting model for homogeneous sensors measurements. An algorithm is applied to implement the model for error correction, in which the signal of any sensor can be esti mated from those of others. The model divides a signal series into two parts, the training part and the estimated part. By comparing the estimated part with the actual one, the proposed method can iden tify a sensor with possible faults and repair its signal. With a small amount of training data, the right parameters for the model in real time could be found by the algorithm. When applied in data analysis for aero engine testing, the model works well. Therefore, it is not only an effective method to detect any sensor failure or abnormality, but also a useful approach to correct possible errors.

关键词： Cointegration Fault tolerant Measurement Multi-sensor Turbine engine

Removal of Cd(Ⅱ)from dilute aqueous solutions by complexation–ultrafiltration using rotating disk membrane and the shear stability of PAA–Cd complex

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Chinese journal of Chemical Engineering 2019年第3期27卷 519-527页

作者： liang Chen Yunren Qiu School of Chemistry and Chemical Engineering Central South University

Removal of cadmium(Ⅱ) ions from dilute aqueous solutions by complexation–ultrafiltration using rotating disk membrane was investigated. Polyacrylic acid sodium(PAAS) was used as complexation agent, as key factors of complexation, pH and the mass ratio of PAAS to Cd^(2+)(P/M) were studied, and the optimum complexation–ultrafiltration conditions were obtained. The effects of rotating speed(n) on the stability of PAA–Cd complex was studied with two kinds of rotating disk, disk Ⅰ(without vane) and disk Ⅱ(with six rectangular vanes) at a certain range of rotating speed. Both of the rejection could reach 99.7% when n was lower than 2370 r·min^(-1) and 1320 r·min^(-1), for disk I and disk Ⅱ, respectively. However, when rotating speed exceeds a certain value,the critical rotating speed(n_c), the rejection of Cd(Ⅱ) decreases greatly. The distribution of form of cadmium on the membrane was established by the membrane partition model, and the critical shear rate(γ_c), the smallest shear rate at which the PAA–Cd complex begins to dissociate, was calculated based on the membrane partition model and mass balance. The critical shear rates(γ_c) of PAA–Cd complex were 5.9 × 10~4 s^(-1), 1.01 × 10~5 s^(-1),and 1.31 × 10~5 s^(-1) at pH = 5.0, 5.5, and 6.0, respectively. In addition, the regeneration of PAAS was achieved by shear induced dissociation and ultrafiltration.

关键词： Complexation-ultrafiltration Membrane Regeneration Shear stability Critical shear rate Shear induced dissociation

Quasi-exactly Solvable Cases of the N-Dimensional Symmetric Quartic Anharmonic Oscillator

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Chinese Physics Letters 2012年第7期29卷 14-17页

作者： PAN Feng XIE Ming-Xia SHI Chang-liang j.P.DRAAYER Department of Physics Liaoning Normal UniversityDalian 116029 Department of Physics and Astronomy Louisiana State UniversityBaton RougeLA 70803-4001USA

The O( N) invariant quartic anharmonic oscillator is shown to be exactly solvable if the interaction parameter satisfies special *** problem is directly related to that of a quantum double well anharmonic oscillator in an external field.A finite dimensional matrix equation for the problem is constructed explicitly,along with analytical expressions for some excited states in the *** corresponding Niven equations for determining the polynomial solutions for the problem are given.

关键词： field harmonic exactly

植物甾醇对桑椹花色苷脂质体及其抗氧化活性的影响

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维普期刊数据库

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食品与发酵工业 2025年第1期51卷 290-296页

作者：梁安雅林羡卜智斌余元善肖更生仲恺农业工程学院轻工食品学院广东广州510225 广东省农业科学院蚕业与农产品加工研究所农业农村部功能食品重点实验室广东省农产品加工重点实验室广东广州510610

植物甾醇的分子结构与胆固醇相似,作为膜结构调节剂,植物甾醇既能调节脂质体膜的结构性质,又能避免胆固醇摄入的负面影响。本研究以植物甾醇替代胆固醇,通过薄膜分散-超声法制备桑椹花色苷脂质体,评价了脂质体的包封率、粒径、电位和微... 详细信息

植物甾醇的分子结构与胆固醇相似,作为膜结构调节剂,植物甾醇既能调节脂质体膜的结构性质,又能避免胆固醇摄入的负面影响。本研究以植物甾醇替代胆固醇,通过薄膜分散-超声法制备桑椹花色苷脂质体,评价了脂质体的包封率、粒径、电位和微观形态等指标,并探究了植物甾醇对脂质体pH稳定性和抗氧化活性的影响。结果表明,与胆固醇脂质体类似,植物甾醇的添加也能够得到粒径小、分散性好、包封率高的桑椹花色苷脂质体。当β-谷甾醇添加量为卵磷脂质量的26%时,桑椹花色苷脂质体贮藏后的DPPH自由基清除能力提高率是添加了等量胆固醇的脂质体的1.6倍。植物甾醇脂质体贮藏前后的氧自由基吸收能力(oxygen radical absorbance capacity,ORAC)优于胆固醇脂质体的,尤其在胆固醇脂质体贮藏后,ORAC值下降2.42倍~3.65倍,植物混合甾醇脂质体的ORAC值则变化不大。综上,采用植物甾醇替代胆固醇制备桑椹花色苷脂质体,可制得较稳定、并具有良好抗氧化活性的脂质体,可为负载生物活性物质的植物甾醇脂质体的构建提供理论基础。

关键词：植物甾醇桑椹花色苷脂质体抗氧化

THERMAL IMAGING STUDY OF SCALAR TRANSPORT IN SHALLOW WAKES

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journal of Hydrodynamics 2012年第1期24卷 17-24页

作者： CHONG K.j.Y UKTHUSYANTHAN N.I. liang Dong-fang TANG Hong-wu Department of Engineering University of CambridgeCambridge KW Ltd FetchamSurreyUK College of Water Conservancy and I tydropowcr Engineering Hohai University Nanjing 210098 China

The thermal imaging technique relies on the usage of infrared signal to detect the temperature *** temperature as a flow tracer,thermography is used to investigate the scalar transport in the shallow-water wake generated by an emergent circular *** imaging is demonstrated to be a good quantitative flow visualization technique for studying turbulent mixing phenomena in shallow waters.A key advantage of the thermal imaging method over other scalar measurement techniques,such as the Laser Induced Fluorescence（LIF）and Planar Concentration Analysis（PCA）methods,is that it involves a very simple experimental *** dispersion characteristics captured with this technique are found to be similar to past studies with traditional measurement techniques.

关键词： environmental hydraulics shallow wake turbulent mixing thermal imaging vortex street

Internal ballistic simulation of multi-burning-rate solid rocket motor based on parameterized feature CAD modelInternal ballistic simulation of multi-burning-rate solid rocket motor based on parameterized feature CAD model

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航空动力学报 2015年第12期30卷 3017-3028页

作者： CHEN Wei liang Guo-zhu School of Astronautics Beijing University of Aeronautics and Astronautics

Internal ballistic simulation(IBS)method of multi-burning-rate solid rocket motor(SRM)was developed based on 3-D burning regression method by parameterized feature CAD model(PFCADM)and lumped parameter,in consideration of time-dependent,erosive-burning-effect from internal ballistic numerical *** driving multi-parameter CAD model based on PFCADM,the approach is capable of conducting the geometric regression simulation of various grain combinations of complex configurations with different burning *** suitably simplifying the internal ballistic numerical algorithm,the problems of coupling geometric regression simulation of sub-grains of different burning rates and high computational consumption of internal ballistic calculation were *** tri-burning-rate grain motor,which had been firing-tested,was used as the validation case of *** results show that,with the 3-D grain regression model and sufficient accurate internal ballistic algorithm,the method realizes IBS of the case in low computationalconsumption prediction of its performance within the accuracy of 2% during *** application of the method provides a practical approach to aid SRM design of multi-burning-rate grain.

关键词： solid rocket motor internal ballistic simulatio multi-burning-rate grain design unsteady flow