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Innovative design and motion mechanism analysis for a multi-moving state autonomous underwater vehicles

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Journal of Central South University 2017年第5期24卷 1133-1143页

作者： GAO Fu-dong HAN Yan-yan wang hai-dong JI Gang Department of Shipboard Aviation Security and Station Management Naval Aeronautical Engineering AcademyQingdao 266041China SANY Heavy Industry Co.Ltd. Changsha 410100China

In order to achieve the functional requirements of multi-moving state, a new autonomous underwater vehicle(AUV) provided with the functions such as the submarine vectorial thrust, landing on the sea bottom, wheel driving on the ground and crawling on the ground was designed. Then five new theories and methods were proposed about the motion mechanism of the AUV such as vectorial thruster technology, design of a new wheel propeller, kinematics and dynamics, navigation control and the ambient flow field in complex sea conditions, which can all conquer conventional technique shortages and predict the multi-moving state performance under wave disturbance. The theoretical research can realize the results such as a vectorial transmission shaft with the characteristics of spatial deflexion and continual circumgyratetion, parameterized design of the new wheel propeller with preferable open-water performance and intensity characteristics satisfying multi-moving state requirements, motion computation and kinetic analysis of AUV's arbitrary postures under wave disturbance, a second-order sliding mode controller with double-loop structure based on dynamic boundary layer that ensures AUV's trajectory high-precision tracking performance under wave disturbance, fast and exact prediction of the ambient flow field characteristics and the interaction mechanism between AUV hull and wheel propellers. The elaborate data obtained from the theoretical research can provide an important theoretical guidance and technical support for the manufacture of experimental prototype.

关键词： multi-moving state autonomous underwater vehicle innovative design motion mechanism wave disturbance

Diagnostic Analyses of the Modified Convective Vorticity Vector in Non-uniformly Saturated Moist Flow

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Atmospheric and Oceanic Science Letters 2009年第3期2卷 142-147页

作者： YANG Shuai wang dong-hai Laboratory of Cloud-Precipitation Physics and Severe Storms （LACS） Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China State Key Laboratory of Severe Weather （LaSW） Chinese Academy of Meteorological Sciences Beijing 100081 China

Because the real atmosphere is non-uniformly saturated, the generalized potential temperature is introduced. The convective vorticity vector, which can depict the occurrence and development of mesoscale deep convective systems, is modified and re-derived in a nonuniformly saturated moist atmosphere (C*). Then, a case study is performed for a frontal rainfall event which occurred near the middle and lower reaches of the Yangtze River in China. The diagnostic results of C* show that, in the lower troposphere, the vertical component of C* (Cz*) can diagnose developments and movements of precipitation and convection better than those of Cm (Cmz, in saturated moist flow) and C (Cz, in dry flow). Cz* is a good predictor for precipitation analyses as well.

关键词： non-uniform saturation generalized potentialtemperature modified convective vorticity vector

The Characteristics of Mesoscale Convective Systems (MCSs) over East Asia in Warm Seasons

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Atmospheric and Oceanic Science Letters 2012年第2期5卷 102-107页

作者： Li Jun wang Bin wang dong-hai State Key Laboratory of Numerical modeling for Atmospheric Science and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Center for Earth System Science Tsinghua University Beijing 100084 China State Key Laboratory of Severe Weather Chinese Academy of Meteorology Beijing 100081 China

Mesoscale convective system (MCS) cloud clusters,defined using an objective recognition analysis based on hourly geostationary infrared satellite data over East Asia during the warm seasons of 1996-2008 (except 2004),were investigated in this *** geographical pattern of MCS distribution over East Asia shows several high-frequency centers at low latitudes,including the Indo-China peninsula,the Bay of Bengal,the Andaman Sea,the Brahmaputra river delta,the south China coastal region,and the Philippine *** are several middle-frequency centers in the middle latitudes,e.g.,the central-east of the Tibet Plateau,the Plateau of west Sichuan,Mount Wuyi,and the Sayan Mountains in Russia;whereas in Lake Baikal,the Tarim Basin,the Taklimakan Desert,the Sea of Japan,and the Sea of Okhotsk,rare MCS distributions are *** are most intensely active in summer,with the highest monthly frequency in July,which is partly associated with the breaking out and prevailing of the summer monsoon in East *** obvious diurnal cycle feature is also found in MCS activities,which shows that MCSs are triggered in the afternoon,mature in the evening,and dissipate at *** patterns over East Asia can be characterized as small,short-lived,or elongated,which move slowly and usually lead to heavy rains or floods.

关键词： Mesoscale Convective System infrared satellite data distribution monthly variation diurnal cycle

The Curl of Q Vector: A New Diagnostic Parameter Associated with Heavy Rainfall

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Atmospheric and Oceanic Science Letters 2008年第1期1卷 36-39页

As a powerful tool to diagnose vertical motion, frontogenesis, and secondary circulation, the Q vector and its divergence are widely used. However, little attention has been given to the curl of Q vector. In this paper, a new set of analyses combining the divergence of the Q vector （DQ） with the vertical component of the curl of the Q vector （VQ） is applied to a Northeastern cold vortex rainfall case. From the derivation, it was found that the expressions of the Q vectors and their divergences in saturated moist flow （DQm） differ from those of dry and unsaturated moist atmosphere （DQ）, while the VQs of various background flows are exactly the same, which largely simplified the analyses. This case study showed that, compared with the DQ, not only can the DQm diagnose precipitation more effectively, but the VQ may also be indicative of precipitation （especially for heavy rainfall and strong convection） because of its direct, close relationship with ageostrophic motion. Thus, the VQ may be computed and analyzed with ease, and may serve as a useful tool for analyses of precipitation and strong convective svstems.

关键词： the divergence of Q vector the curl of Qvector Northeastern rainfall

Characteristics of a Terrain-Following Sigma Coordinate

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Atmospheric and Oceanic Science Letters 2011年第3期4卷 157-161页

作者： LI Yi-Yuan wang Bin wang dong-hai State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical FluidDynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Center for Earth System Science Tsinghua University Beijing 100084 China State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China

This study quantifies the main characteristics of a terrain-following, G-coordinate through mathematical analyses of its covariant and contravariant basis vectors as well as the vertical coordinate of σ. A 3-D schematic of the σ-coordinate in a curvilinear coordinate system is provided in this study. The characteristics of the basis vectors were broken down into their ＂local vector charac- teristics＂ and ＂spatial distribution characteristics＂, and the exact expressions of the covariant; in addition, the con- travariant basis vectors of the G-coordinate used to eluci- date their detailed characteristics were properly solved. Through rewriting the expression of the vertical coordi- nate of G, a mathematical expression of all the cr-coor- dinate surfaces was found, thereby quantifying the so- called terrain-following characteristics and lack of flexi- bility to adjust the slope variation of G-coordinate sur- faces for the classic definition of G. Finally, an analysis on the range value of the vertical coordinate demonstrated that the general value range of G could be obtained by eliminating the G-coordinate surfaces below the Earth＇s surface. All these quantitative descriptions of the charac- teristics of G-coordinate were the foundation for improv- ing the G-coordinate or creating a new one.

关键词： quantitative description sigma coordinate 3-D schematic basis vectors non-orthogonal

Validation of IASI-Retrieved Atmospheric Water Vapor Data over the Tibetan Plateau Region

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Atmospheric and Oceanic Science Letters 2013年第3期6卷 167-172页

作者： CHEN Ting wang dong-hai LI Guo-Ping ZHANG Yu-Wei College of Atmospheric Sciences Chengdu University of Information Technology State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences

The Infrared Atmospheric Sounding Interferometer (IASI) is a new-generation ultraspectral atmospheric sounding instrument mounted on the MetOp-A, the first operational polar-orbiting satellite developed by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). It is an ultrahigh spectral-resolution atmospheric detector which can detect atmospheric chemical composition, temperature, and humidity profiles with high accuracy and resolution. In the present study, through comparative analyses of the similarities and differences between the IASI and the radiosonde observation (RAOB) water vapor data, and between the IASI and the Aqua-AIRS water vapor retrievals, a detailed and systematic assessment of the credibility of the IASI water vapor retrievals over the plateau region was made. A comparison of the IASI retrievals with the AIRS retrievals and the RAOB measurements over the Tibetan Plateau revealed that the IASI retrieval data are reliable and can be used for conducting further studies.

关键词： IASI Tibetan Plateau water vapor profiles quality validation

Analysis and innovation of key technologies for autonomous underwater vehicles

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Journal of Central South University 2015年第9期22卷 3347-3357页

作者：高富东韩艳艳王海东徐男 Department of Shipboard Aviation Security and Station Management Naval Aeronautical Engineering Academy SANY Heavy Industry Co. Ltd

As the mission needs of the autonomous underwater vehicles(AUV) have become increasingly varied and complex,the AUVs are developing in the direction of systematism, multifunction, and clustering technology, which promotes the progress of key technologies and proposes a series of technical problems. Therefore, it is necessary to make systemic analysis and in-depth study for the progress of AUV's key technologies and innovative applications. The multi-functional mission needs and its key technologies involved in complex sea conditions are pointed out through analyzing the domestic and foreign technical programs, functional characteristics and future development plans. Furthermore, the overall design of a multi-moving state AUV is proposed. Then, technical innovations of the key technologies, such as thrust vector, propeller design, kinematics and dynamics, navigation control, and ambient flow field characteristics, are made, combining with the structural characteristics and motion characteristics of the new multi-moving state AUV. The results verify the good performance of the multi-moving state AUV and provide a theoretical guidance and technical support for the design of new AUV in real complex sea conditions.

关键词： autonomous underwater vehicle(AUV) key technology overall design complex sea condition

Kinetics of leaching lithium from lepidolite using mixture of hydrofluoric and sulfuric acid

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Journal of Central South University 2020年第1期27卷 27-36页

作者： wang hai-dong ZHOU An-an GUO Hui LÜMeng-hua YU hai-zhao School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China

The fluorine-based chemical method shows great potential in leaching lithium(Li) from lepidolite. Leaching kinetics of Li in a mixture of sulfuric acid and hydrofluoric acid, which is a typical lixivant for the fluorine-based chemical method, was carried out under crucial factors such as different HF/ore ratios(1:1-3:1 g/mL) and leaching temperatures(50-85℃). The kinetics data fit well with the developed shrinking-core model, indicating that the leaching rate of Li was controlled by the chemical reaction and inner diffusion at the beginning of leaching(0-30 min) as a calculated apparent activation energy(Ea) of 20.62 kJ/mol. The inner diffusion became the rate-limiting step as the leaching continues(60-180 min). Moreover, effects of HF/ore ratio and leaching temperature on selective leaching behavior of Li, Al and Si were discussed. 90% of fluorine mainly existed as HF/F-in leaching solution, which can provide theoretical guidance for further removal or recovery of F.

关键词： lepidolite lithium extraction fluorine-based chemical method hydrofluoric acid selective leaching leaching kinetics

Simulation of the evolution of the latent heat processes in a mesoscale convective system accompanied by heavy rainfall over the Guangzhou region of South China

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Atmospheric and Oceanic Science Letters 2017年第1期10卷 58-64页

作者： LI Jiang-Nan WU Kai-Lu DING Cheng-Hui YANG Chao-Feng LI Fang-Zhou wang dong-hai FENG Ye-Rong School of Atmospheric Sciences Sun Yat-sen UniversityGuangzhouChina State Key Laboratory of Severe Weather(LaSW) Chinese Academy of Meteorological SciencesBeijingChina Guangdong/CMA Key Laboratory of Regional Numerical Weather Prediction GuangzhouChina

A cloud-scale WRF simulation was used to investigate the cloud microphysical processes and threedimensional structure of latent heat budgets in different stages of a mesoscale convective system（MCS） accompanied by heavy rain that occurred in the Guangzhou region of South *** results enable us to draw the following conclusions：（1） During the development and mature stages,the main heating processes were condensation below 400 hPa and deposition above 400 *** main cooling processes were evaporation and *** the dissipation stage,all the microphysical processes were weak.（2） Water vapor condensed into cloud water,and rainwater significantly contributed to all stages of the MCS.（3） During every stage of the MCS,the primary cooling microphysical process was the evaporation of rainwater,which was maximum during the mature stage.

关键词： Mesoscale convective system microphysical process latent heat budget