Volume 36,Issue 1,2013 Table of Contents

1 Analysis of nonlinear vibration induced by single radial ball bearing

CHEN Xiaoan , LIU Junfeng , ZHANG Peng , SHAN Wentao , WU Guoyang

2013, 36(1):1-6. DOI: 10.11835/j.issn.1000-582X.2013.01.001

[Abstract](1878) [HTML](530) [PDF 6.54 M](1667)

Abstract:
Beginning with the structural characteristics of ball bearings,the parametric vibration of single radial ball bearing-rotor system,which is induced by the varying compliance vibration,is studied through the analysis of the stress state in bearing,then a series of forced vibrations caused by the manufacture error and the installation deflection of the bearing are analyzed,and different frequency components of the nonlinear vibration result from rolling bearing are summarized. Finally,a validation test is carried out on a 120MD60Y6-type motorized spindle,and vibration signals are purified with the use of the low-pass filtering and band-pass filtering. The results from the spectrum analysis show that the vibration frequency components produced by the single radial ball bearing take a large proportion in vibration signals at low speed. With the rise of the rotational speed,the amplitudes of these vibration frequency components vary slightly,meanwhile the proportion of their amplitudes in vibration signals decrease abruptly. These conclusions are useful to the fault diagnosis and the dynamic analysis of rolling bearing-rotor system.

2 Discussion on similarities and differences between CFX and Fluent software in calculating journal bearing lubrication

MENG Fanming , CHEN Yuanpei , YANG Tao

2013, 36(1):7-14. DOI: 10.11835/j.issn.1000-582X.2013.01.002

[Abstract](2972) [HTML](660) [PDF 11.59 M](1383)

Abstract:
The calculation of journal bearing’s performances is taken as an example,and similarities and differences between the modules CFX and Fluent of ANSYS are analyzed using the CFD (computational fluid dynamics) theory. To this end,the calculation models are established and solved using the above modules. And the tribological parameters of the journal bearing are comparatively analyzed at different eccentricity ratios,rotational speeds and the ratios of bearing’s length-diameter. The conclusion reached is that results from two modules have similar overall variation tendency in the bearing performances. However,the maximum pressure and load-carrying capacity by CFX are smaller,while the friction coefficient is greater,compared with those by Fluent. And greater deviations appear at high eccentricity,low rotational speed,or low ratio of bearing’s length-diameter.

3 A valve camshaft load torque calculation and camshaft vibration control analysis

HU Yumei , FAN Fang , LEI Yingfeng , HU Chengtai

2013, 36(1):15-21. DOI: 10.11835/j.issn.1000-582X.2013.01.003

[Abstract](1904) [HTML](484) [PDF 9.08 M](1993)

Abstract:
Aiming at the overhead camshaft valve mechanism,the theoretical and numerical solutions of camshaft load torque are calculated respectively by a derived formula and transient finite element analysis. The two solutions show good agreement,thus the correctness of the transient finite element model is verified. By combining with camshaft instantaneous constraint modal analysis and vibration response with consideration of gas pressure,it is found the position of camshaft which easily excites resonance and the main influence factors of camshaft vibration. Then the effect of the width of bearing seat on the camshaft vibration is investigated and the results show that the vibration of camshaft is mainly bending vibration,appropriate width of bearing seat can effectively control the camshaft vibration.

4 Eye localization and state analysis for driver fatigue detection

ZHANG Wanzhi , WANG Zengcai , LI Yunxia

2013, 36(1):22-28. DOI: 10.11835/j.issn.1000-582X.2013.01.004

[Abstract](1593) [HTML](459) [PDF 7.72 M](1414)

Abstract:
To solve the problem of eye precise localization in head multi-position,an algorithm based on skin color and texture feature is proposed. Face is detected based on skin color and according to the gray difference between eyes and other parts,and eye candidate areas are found with the method of binarization and morphological image processing. Eyes are detected by calculating the texture characteristics values of candidate areas. The method of black fleck fitting elliptic is used to check the factuality of the 2 detected eyes and measure the eye opening extent. The experimental results demonstrate the texture characteristics values of candidate areas are still different when head angle changes and the proposed method can accurately detect eyes. The method is simple and fast,and not influenced by driver head posture.

5 Application of frequency shifting in truncating substructure low order normal modes

LUO Hong , ZHANG Jingcheng , LI Xingquan , LI Yingqiang

2013, 36(1):29-34. DOI: 10.11835/j.issn.1000-582X.2013.01.005

[Abstract](1531) [HTML](399) [PDF 5.65 M](1389)

Abstract:
A method to cutoff substructure low order normal modes in component mode synthesis is proposed. Frequency shifting technique is introduced in substructure free vibration differential equation. Quasi-static constraint mode is taken into coordinate transformation and the contribution of substructure low order normal modes to system middle frequency modes is reduced,thus substructure low order normal modes truncation is achieved. This technique is used to compute dynamic characteristics of a body-in-white FEM mode in the frequency band of 160~190 Hz. The results show that compared with traditional component mode synthesis,which keeps 1 836 normal modes,this method only needs 297 normal modes and saves 27.7% calculation time. It means frequency shifting technique can improve the computational efficiency for middle frequency band dynamic characteristics of complex structure.

6 Research on analysis of force and contacting stress for the discrete teeth harmonic drives

WANG Su , BAI Xin , CHEN Shixian , WANG Chunyan

2013, 36(1):35-42. DOI: 10.11835/j.issn.1000-582X.2013.01.006

[Abstract](1369) [HTML](639) [PDF 9.92 M](1275)

Abstract:
Mechanical analysis for the discrete teeth harmonic drive gear pair is carried out. The force on discrete teeth is calculated based on the deformation coordination equation,and the contact stress of meshing pair is obtained by Hertz equation. According to transmission periodicity of the discrete gear harmonic wave and the input angle values of continuous sampling wave generator,the distribution of discrete teeth harmonic drive meshing force and contract stress in rigid tooth profile,tooth wave generator and discrete teeth is obtained. By studying the top cutting phenomena in rigid tooth profiles,the change trend of meshing force and contact stress on the contact surface is found,and positions for high meshing force and high contact stress in transmission are also found,in order to provide reference for further intensity and structure optimization design.

7 Design of ship-block production scheduling oriented knowledge navigation system

HUANG Yongwen , JIANG Zuhua , MAO Zujie , WANG Jun

2013, 36(1):43-49. DOI: 10.11835/j.issn.1000-582X.2013.01.007

[Abstract](1716) [HTML](476) [PDF 12.08 M](1293)

Abstract:
A knowledge map based knowledge navigation system model is established by combining the domain characteristics of production scheduling to counter the schedulers’ low-efficiency on account of confusion during production scheduling process. Key technology points,i.e. knowledge ontology building,semantic node integration,ontology based semantic relevance and the map implementation technique are analyzed. The knowledge navigation system is applied to ship-block production scheduling decision-making process. The method and technologies are verified in the ship-block scheduling process of a workshop in a shipbuilding factory.

8 Development of an apparatus for testing heat-resistance time of combustible devices

WANG Guangjian , LIU Zhonghua , YU Li

2013, 36(1):50-54. DOI: 10.11835/j.issn.1000-582X.2013.01.008

[Abstract](1532) [HTML](574) [PDF 6.07 M](1137)

Abstract:
Based on the characteristics of combustible cartridge case, a test method for heat-resistance time of minor-caliber rapid-fire gun with high rate of fire is proposed and test apparatus prototype is developed. The method is to do the flame detection through the use of photomultiplier tubes combined with optical fiber and detecting smoke by using the infrared and receiver combined with optical fiber. The test experiments show that the apparatus can effectively test the signal smoke and flames. Moreover, it can be applied to the heat-resistance test of other nonmetallic materials.

9 Measurement and analysis of SF6 decomposition products under two types of partial discharges

TANG Ju , HU Yao , QIU Yinjun , YUAN Jingfan , ZENG Fuping , ZHANG Xiaoxing

2013, 36(1):55-61. DOI: 10.11835/j.issn.1000-582X.2013.01.009

[Abstract](1651) [HTML](317) [PDF 7.70 M](1168)

Abstract:
In order to recognize partial discharge by analysis of SF6 decomposition products, the decomposition characteristic of SF6 under different partial discharges should be investigated, and also the feature parameters of decomposition products should be found. The decomposition of SF6 is simulated under partial discharge generated by needle defect and contamination defect respectively on the SF6 decomposition equipment made especially for the experiment. Three kinds of byproducts namely CF4, SO2F2 and SOF2 are detected, and their concentration changes with time are also studied. After that, the characteristics of three kinds of concentration ratios namely SOF2/SO2F2, SO2F2/CF4 and SOF2/CF4 under two defects are analyzed. The results show that SOF2, SO2F2 and CF4 exist in the byproducts under both the two defects. Moreover, the increase rules of the three kinds of byproducts under two defects are obviously different. Meanwhile the results illustrate that the three contamination ratios under the two defects have a notable disparity. Therefore the concentration ratios of the decomposition products can be used as feature parameters for partial discharge recognition.

10 An asymmetric fault ride-through control strategy for PMSG wind turbine

DU Xiong , DAI Pengceng , LI Shanhu , ZHOU Luowei

2013, 36(1):62-68. DOI: 10.11835/j.issn.1000-582X.2013.01.010

[Abstract](1604) [HTML](455) [PDF 8.40 M](1168)

Abstract:
In order to improve the asymmetric fault ride-through capability of PMSG wind turbine, a novel control method is proposed. This method can reduce the negative sequence current component in the grid side converter and eliminate the 2 nd order voltage fluctuation in the DC link capacitor voltage of the AC-DC-AC converter. The proposed control method employs the grid voltage feed forward to reduce the grid side negative sequence current component, while a novel power control concept, output power of generator tracking the grid side power, is applied to control the electro-magnetic power of the PMSG to eliminate the 2 nd order voltage ripple in the DC link. Simulation results for a 1 MW case study show that the control method can eliminate the grid side negative sequence current component and the 2 nd order voltage ripple in the DC link at the same time.

11 Multi-field coupled numerical simulation of volume conduction energy transfer

TANG Zhide , LIU Hailong , CHEN Xiufa , XIE Xiaohui , HOU Deming

2013, 36(1):69-74. DOI: 10.11835/j.issn.1000-582X.2013.01.011

[Abstract](1396) [HTML](303) [PDF 7.89 M](1340)

Abstract:
The research on volume conductive model can be used in designing the conductive systems and optimizing the energy transfer parameters. By considering the coupling of circuit, electromagnetic-field and temperature-field, a 3-D multi-filed coupling model is developed. On the circuit level, the simulation of volume conduction, real-time monitoring for the temperature of skin tissue are achieved, which provides direct theoretical guidance for energy transfer optimization design. With the software FEM 3.5, a volume conduct multi-field coupling model is built to verify the feasibility of volume conduction, which also lays foundation for further optimize energy transfer efficiency.

12 Nominal electric field calculation at the ground level of UHV DC transmission lines based on radial basis function method

LI Yongming , HUANG Hongpei , ZHANG Huaiqing , XU Luwen , LI Gang , FENG Ling , ZHU Yanju

2013, 36(1):75-80. DOI: 10.11835/j.issn.1000-582X.2013.01.012

[Abstract](1570) [HTML](329) [PDF 6.95 M](1258)

Abstract:
Nominal electric field at ground level is one of the important factors for the design of transmission lines. FEM meets two big challenges in electromagnetic field computation. One comes from the mesh generation, which is a big difficulty especially in complex geometry. The other is the long time calculation. So the radial basis function method is introduced to calculate the nominal electric field at the ground level of UHVDC transmission lines. Not only the definition and ideas, but also the detailed implementation procedure of radial basis function method are presented. Computer programs are developed to simulate the model and the influences of conductor configuration on nominal electric field intensity are analyzed. Examples of calculation show that the results are accorded with those available literatures, and agreed satisfactorily with analytic solutions of the coaxial cable model. The height of the polar lines and conductor inter-spacing has a remarkable influence on ground nominal electric field intensity while the sub-conductor radius and number of sub-conductors have little influence.

13 Minimum variance beamforming combined with MV-Based coherence factor applied to medical ultrasound imaging

WANG Ping , XU Qin , FAN Wenzheng , GAO Yang , HE Wei , CHEN Minyou

2013, 36(1):81-85. DOI: 10.11835/j.issn.1000-582X.2013.01.013

[Abstract](1731) [HTML](389) [PDF 5.70 M](1114)

Abstract:
In medical ultrasonic imaging, minimum variance beamforming (MV)can effectively improve imaging resolution, but the contrast is not improved. By considering the low contrast of minimum variance beamforming, a medical imaging method combined minimum variance beamforming and MV-based coherence factor is presented. First, the coherent sum in coherence factor is replaced by the output of MV to obtain weighting factor; and then the factor is used to weight the results of minimum variance beamforming. The simulated results indicate that the proposed method in the aspects of resolution and contrast is better than traditional delay and sum, minimum variance beamforming and medical imaging method combining minimum variance beamforming and coherence factor.

14 The Gram-Schmidt orthogonal data fitting method for the designing of the gradient magnetic field of the unilateral NMR

HE Wei , HE Xiaolong , XU Zheng , GUO Pan

2013, 36(1):86-91. DOI: 10.11835/j.issn.1000-582X.2013.01.014

[Abstract](1993) [HTML](343) [PDF 6.95 M](1622)

Abstract:
By considering the shortcomings of the traditional Halbach magnet structure which is closed and cannot be applied to the open NMR, an open and semi-circle Halbach magnet structure is proposed. Adjusting the semi-major axis of the elliptic curve which the center of magnets are placed on and calculating the flatness of the magnetic field on different heights, a magnet structure with best flatness is achieved by data fitting method. The optimizing result shows that the best magnet structure can generate a magnetic fields which flatly distributes in the horizontal direction of the 50 mm×50 mm area in the YOZ plane. The gradient is distributed in the vertical direction with gradient of 2 mT/mm. Magnetic field is uniformly distributed in the area of 4 mm×4 mm with uniformity of 1.3×10 -3 and magnetic field of 0.073 9 T. An actual magnet model is constructed based on the result of the optimal design; the measurement result is consistent with the design. The advantage of this magnet structure is that the gradient magnetic field is generated by the permanent magnet naturally, and the extra gradient coil isn’t needed, so the designing of the gradient coding system is simplified.

15 Analysis on the effect of substation structure on grounding grid corrosion diagnosis

LIU Yugen , LENG Di , XIAO Leishi , TIAN Jinhu

2013, 36(1):92-97. DOI: 10.11835/j.issn.1000-582X.2013.01.015

[Abstract](1411) [HTML](387) [PDF 7.87 M](1191)

Abstract:
The measured data of grounding grid corrosion diagnosis are often influenced by steel structural frames, and thus the diagnosis is inaccurate. Based on grounding grid corrosion diagnosis theory, the characteristics of structure frames number, length, layout location and resistance of the influence on the diagnosis result are analyzed by establishing the simulation model. The results show that regardless of the structural frames’ number, layout location and span length, the existence of structural frames reduces the diagnosis sensitivity of fault branch which is near structural frames, making the extent of diagnosed branch corrosion is lower than that without framing. However, the diagnosed corrosion of the branch which is away from the structural frames won’t be influenced. The bigger the resistance of the structural frames connected to grounding grid, the smaller the diagnosis result of interference. Choose the grounding grid branch which has no obvious increase multiples near structural frames as excavation object can improve the diagnostic accuracy.

16 Preparation and characterization of carbon cones by reaction plasma

CHEN Yu’an , CHEN Xuan , XU Xingzi , WANG Biben

2013, 36(1):98-102. DOI: 10.11835/j.issn.1000-582X.2013.01.016

[Abstract](1300) [HTML](416) [PDF 4.49 M](1094)

Abstract:
Carbon cones are prepared on Si substrates film in plasma-enhanced hot filament chemical vapor deposition system using CH4, H2 and NH3 as the reaction gas, and the substrates are deposited with Ti and carbon film, respectively. Morphology and structure of the carbon cones are characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX)and micro-Raman spectroscopy. The SEM results indicate that the carbon cones are formed on the Si substrate deposited with carbon film. Furthermore, the EDX and Raman spectra indicate that the formed carbon cones are carbon nitride structure, which are composed of sp 3 C-N, sp 2 C and sp 2 C=N bonds. According to the mechanisms of sputtering and diffusion, the formation of carbon cones is analyzed. Simultaneously, the photoluminescence background in the Raman spectrum of carbon cones is analyzed, and results indicate that the carbon cone evolves from nonpolar carbon material to polarity carbon material due to the doping of nitrogen.

17 Experiments on triaxial mechanical properties of soft coal containing gas

ZHAO Hongbao , ZHANG Hongbing , YIN Guangzhi

2013, 36(1):103-109. DOI: 10.11835/j.issn.1000-582X.2013.01.017

[Abstract](1304) [HTML](299) [PDF 8.65 M](988)

Abstract:
Taking briquette specimens composed by soft coal with outbursting trends as research object, systematic research of the influence on triaxial mechanical properties of soft coal containing gas caused by confining pressure and gas pressure is done. The results show that confining pressure can significantly affect mechanical properties of soft coal containing gas, the compression phase of soft coal containing gas is obvious and the triaxial strength is increased gradually as confining pressure is increased; the influence on elastic modulus and shape of stress-strain curve is not obvious. The triaxial strength of soft coal containing gas shows decrease trend as gas pressure is increased; the influence on strength of soft coal containing gas caused by gas pressure is obvious when the confining pressure is smaller, but it is not obvious when the confining pressure is bigger. the influence caused by gas pressure on elastic modulus and deformation of yield step is not obvious; gas pressure has not only obvious mechanical effects,but also have chemical action on soft coal containing gas; stress-strain curve of soft coal containing gas can be expressed by conic, the influence caused by gas pressure can be considered as equivalent confining pressure effects.

18 Analysis on drag coefficients of bundled conductors under wind load

CAI Mengqi , YAN Bo , LIU Xiaohui , HU Jing

2013, 36(1):110-114. DOI: 10.11835/j.issn.1000-582X.2013.01.018

[Abstract](1927) [HTML](325) [PDF 8.04 M](1403)

Abstract:
Drag coefficients of quad-bundled conductor under different wind speeds and attack angles are firstly determined by means of wind tunnel test. Meanwhile, the drag coefficients are obtained by numerical simulation method and the results are consistent with those by the wind tunnel test. Furthermore, cross flows around six-bundled and eight-bundled conductors are numerically investigated, and the drag coefficients are then determined. Compared with the determination method of wind load on conductor in current Chinese code and the IEC code for the design of transmission line, the drag coefficients defined in the Chinese code may be too large for bundled conductors, and may need to be adjusted based on further theoretical and wind tunnel test investigation.

19 Kinetics on degradation of CODcr in mustard comprehensive wastewater by electro-Fenton process

ZHANG Zhi , YIN Xiaojing

2013, 36(1):115-120. DOI: 10.11835/j.issn.1000-582X.2013.01.019

[Abstract](1427) [HTML](327) [PDF 6.10 M](1250)

Abstract:
The treatment efficiency of mustard comprehensive wastewater with high salt by electro-Fenton is studied to solve the problem that microorganism is inhibited by high salt and improve the unstable performance of biological treatment. CODcr removal effect and its influencing factors in high salt wastewater by electro-Fenton process are mainly investigated, and the degradation kinetics of CODcr is analyzed. The results show that CODcr removal rate reaches 76.33 % after 120 min at the conditions that current density of 10 A/dm 2, ferrous sulfate dosage 1.0 mmol/L, electrode spacing 15 mm, pH=5, RuO2-IRO2-SnO2-TiO2/Ti quaternary as anode, titanium mesh as cathode. Kinetic analysis shows that the degradation curve of CODcr consists with the first-order response characteristics and the value of the kinetic constant is 0.0121 min -1 when COD of raw wastewater is 4 225 mg/L. By linear regression equation, kinetics model of CODcr degradation is established. The model possesses higher regression rate (R 2=99.25%) and has higher coincide degree with the experimental results.

20 POD analysis of flow structures in thermally stratified flow in a confined space with the effects of horizontal wind

YANG Dong , ZHU Shi , HUO Ran , HU Longhua

2013, 36(1):121-126. DOI: 10.11835/j.issn.1000-582X.2013.01.020

[Abstract](1813) [HTML](380) [PDF 8.82 M](1386)

Abstract:
PIV measurements are carried out on the thermally stratified flows under different horizontal shear intensities in a confined space. Proper orthogonal decomposition (POD) is used to analyze the structures of these thermally stratified flows. Results show that, at the conditions without forced horizontal airflow, the low-order POD mode constitutes a high proportion of the total energy of the flow, and the horizontal flow is the dominant flow structure. The horizontal shear drives the energy to dissipate from large structure to smaller structures. Relative to the conditions without forced horizontal airflow, the ratios of vertical kinetic energy to horizontal kinetic energy become higher for each order of POD mode in the conditions with forced horizontal airflow. This indicates that horizontal shear can result in stratification instability and enhance the mass exchange in the vertical direction.

21 Development of integrated reactors for domestic garbage and town sludge

WU Zhengsong , ZHI Yue , HE Qiang , TANG Shitian , LING Jianjun , PAN Mingxia

2013, 36(1):127-132. DOI: 10.11835/j.issn.1000-582X.2013.01.021

[Abstract](1763) [HTML](445) [PDF 6.38 M](1575)

Abstract:
Aiming at domestic garbage aerobic compost and town sludge anaerobic treatment, on the basis of reactor TISTD (the integrated of sludge thickening and digestion)which is developed by the authors’ team, a TIDGTS (the integrated of domestic garbage and town sludge)reactor is designed.The reactor is made up of garbage and sludge chambers.Aerobic compost is adopted in the garbage chamber, while anaerobic fermentation is used in the sludge chamber, thus garbage and sludge can be treated in the same reactor.32~36 ℃ of sludge digestion can be ensured by the heat from sludge digestion, and 20 L sludge and 15 kg garbage can be treated per day.While inlet sludge moisture content is 97.2%~99.8% and VS/TS is 0.45~0.69, the discharged sludge moisture content is 92.7%~96.1% and VS/TS is 0.28~0.42.When the inlet garbage moisture content is 73.5% and VS/TS is 0.65~0.88, the discharged garbage moisture content is 48.6% and VS/TS is 0.32~0.44.The results show that the efficiency of concentration and digestion is near to TISTD which is heated by heating wire.

22 Experiments on reduction roasting and bio-dephosphorization of high-phosphorus oolitic hematite

HU Chun , GONG Wenqi , LI Yubiao , ZHONG Lele , XIN Zhenkai , WAN Jing , LIU Xuhong

2013, 36(1):133-139. DOI: 10.11835/j.issn.1000-582X.2013.01.022

[Abstract](1673) [HTML](360) [PDF 6.82 M](1292)

Abstract:
Experiments are carried out on high-phosphorus oolitic hematite in western Hubei, using the method of reduction roasting and low intensity magnetic separation, and Aspergillus niger is used to do the research of bioleaching dephosphorization on concentrate.The orthogonal test results show that the descending order of factors influencing concentrate grade is calcinations temperature, roasting time, reduction ratio, grinding grain.The best condition for reduction roasting and low intensity magnetic separation is calcinations temperature 900 ℃, roasting time 25 min, reduction ratio 6%, and grinding grain -0.074mm95.08%.On these conditions, concentrate grade is 57.25% and recycling rate is 90.20%.Aspergillus niger has a strong removal capability on phosphorus in concentrates.After 8 days of microbiological leaching, removal of phosphorus is 79.68% with lower pulp density, and the percentage of phosphorus is reduced to 0.17% from 0.85%, which provides the foundation of application on dephosphorization by microorganism.

23 The variation rules of pupil size under classroom lighting condition

HUANG Haijing , CHEN Gang , YAN Yonghong

2013, 36(1):140-144. DOI: 10.11835/j.issn.1000-582X.2013.01.023

[Abstract](2089) [HTML](888) [PDF 5.14 M](1339)

Abstract:
For the purpose of studying the rule of the pupil size variation while the luminance level is changing under the classroom’s lighting condition, the variation values of 3 student’s pupil area that under 5 kinds background luminance affording by three kinds of fluorescent illuminant of different color temperature (2 700 K, 4 000 K, 6 500 K)are measured, with iView X eye tracking and the experiment of the measure system of pupil size under classroom lighting to simulate the classroom lighting.The result shows that, the relationship between pupil area and background luminance is negative exponential function under 3 color temperature fluorescent illuminant；under the classroom lighting condition, the pupil area gets smaller when the background luminance is higher, and is getting stable gradually；under the same background luminance, the pupil area is smaller under the lighting of higher color temperature fluorescent.

24 A panel model of isotope concentration-flow coupled field in groundwater systems

TONG Haibin , FU Xudong , CHEN Jiansheng

2013, 36(1):145-150. DOI: 10.11835/j.issn.1000-582X.2013.01.024

[Abstract](1561) [HTML](454) [PDF 4.38 M](1065)

Abstract:
Several previous general lumped parameter model of radioisotope concentration field in groundwater systems, such as EM, PM and EPM model, are introduced, and the ambiguous physical meaning of response functions within these models are pointed out.And then, based on the radioactive decay principles and mass conservation principle, assuming that 1)the fluid system is in steady state, 2)infiltration rate is constant, and 3)the horizontal transport of water flow rate is constant, a general lumped parameter model of radioisotope concentration-fluid coupled field in groundwater systems is deduced under these conditions, that is, Panel model.Compared with the above mentioned models, this new model is built on a clear physical basis with a definite physical meaning of each parameter, so that it could make accurate interpretations on radioisotope data of the relevant water flow system, and provide more precise mathematical foundation on quantitative analysis and simulation of radioisotope concentration.

Home

Volume 36,Issue 1,2013 Table of Contents

Current Issue

Volume

Issue

Most Read

Most Cited

Most Downloaded