长江水位下降及降雨条件下荆江河段岸坡渗流特性研究

为了研究荆江河段岸坡土体的渗流特性及失稳机理,对荆江中州子护岸工程段河岸土样做了渗透系数和土水特征曲线室内试验,并基于Van Genuchten模型对土水曲线的试验结果进行拟合。在获得土体水力参数的基础上,根据该河段岸坡二元结构土体的特点,基于饱和—非饱和渗流理论,探讨了水位下降及降雨条件下岸坡不同粘性土层厚度对岸坡渗流场的影响规律。结果表明,地下水的下降速率随粘性土层厚度的增加而减少;粉质粘土层厚度越大,降雨对岸坡孔压场的影响范围也越大,且在一定程度上增大了土体的暂态饱和区,不利于岸坡的稳定性。     

HT-7U放电真空室支撑结构的设计和应力分析

结合ＨＴ－７Ｕ超导托卡马克核聚变装置中等离子体运行特点,提出了一种低刚性支撑结构作为放电真空室的本体支撑,并借助ＣＯＳＭＯＳ／Ｍ大型有限元分析程序,进行了全面的校核和应力分析,为结构的进一步研制提供了理论依据。     

基于单纯形法的回旋加速器平衡轨道求解

通过引入描述轨道闭合程度的目标函数,本文将求解回旋加速器平衡轨道的物理问题转换为求目标函数极小值的数学问题,利用单纯形法找到目标函数的最优解,从而实现了平衡轨道求解。该方法可在给定初始动能、初始方位角、初始半径、初始径向动量中任意两个量的条件下求解相应的平衡轨道。     

SC200超导回旋加速器磁场垫补方法研究

考虑磁铁材料的非线性、不均匀性以及有限元数值计算的精度有限,在设计主磁铁时都留有一定裕量,在完成磁铁加工组装后,根据磁场的实际测量结果对磁铁进行垫补获得理想的目标磁场分布,这样可以保证工程稳妥实施。因此磁铁垫补是加速器主磁铁设计制造的一个重要环节。本文基于SC200主磁铁模型,利用有限元分析软件TOSCA,首先研究了不同的磁极切削参数对中平面主磁场的响应影响;其次考虑到相邻切槽对中平面磁场影响的叠加效应,从理论上推导出一种求解垫补量的方法;最后通过模拟的方法验证了磁场垫补的可行性,为将来实际磁场垫补提供了有效的依据。     

Design of a Wedge-Shaped Toroidal Field Winding for KTX Device

The KTX device is a reversed field pinch(RFP)device currently under construction.Its maximum plasma current is designed as 1 MA with a discharge time longer than 100 ms.Its major radius is 1.4 m and its minor radius is 0.55 m.One of the most important problems in the magnet system design is how to reduce the TF magnetic field ripple and error field.A new wedgeshaped TF coil is put forward for the KTX device and its electromagnetic properties are compared with those of rectangular-shaped TF coils.The error field Bn/Btof wedge-shaped TF coils with6.4 degrees is about 6%as compared with 8%in the case of a rectangular-shaped TF coil.Besides,the wedge-shaped TF coils have a lower magnetic field ripple at the edge of the plasma region,which is smaller than 7.5%at R=1.83 m and 2%at R=1.07 m.This means that the tokamak operation mode may be feasible for this device when the plasma area becomes smaller,because the maximum ripple in the plasma area of the tokamak model is always required to be smaller than 0.4%.Detailed analysis of the results shows that the structure of the wedged-shape TF coil is reliable.It can serve as a reference for TF coil design of small aspect ratio RFPs or similar torus devices.     

Design of Tokamak ELM Coil Support in High Nuclear Heat Environment

In Tokomak, the support of the ELM coil, which is close to the plasma and subject to high radiation level, high temperature and high magnetic field, is used to transport and bear the thermal load due to thermal expansion and the alternating electromagnetic force generated by high magnetic field and AC current in the coil. According to the feature of ITER ELM coil, the mechanical performance of rigid and flexible supports under different high nuclear heat levels is studied. Results show that flexible supports have more excellent performance in high nuclear heat condition than rigid supports. Concerning thermal and electromagnetic （EM） loads, optimized results further prove that flexible supports have better mechanical performance than rigid ones. Through these studies, reasonable support design can be provided for the ELM coils or similar coils in Tokamak based on the nuclear heat level.     

Thermal and Hydraulic Analysis of the ITER Upper Vertical Stabilization Coil

The ITER upper vertical stabilization（VS） coil is a part of the ITER in-vessel coil（IVC） system, which has the abilities of restraining edge localized modes（ELMs） and maintaining plasma vertical stability. Preliminary structural analysis of the coil has revealed serious thermal stress problems. Due to the very restricted geometry space, it is necessary to perform detailed analysis on thermal and hydraulic characteristics to help optimal design of the coil. It will focus on the temperature distribution and energy balance, as well as some key factors, such as the coolant flow state and surface emissivity, which have influences on the coil performance. The APDL code and some hand calculations are employed in the analysis. The results show that the coolant convection can effectively take away the heat deposited in the coil. But improving the coolant flow state can hardly mitigate the peak temperature occurring at the edges of coil attachments, which are located far away from the coolant. Thermal radiation was expected to be a good method of cooling down these parts. But the reality is not so optimistic since it usually contributes little in the whole energy balance. However, the effect of thermal radiation will become remarkable when bad scenarios or accidents take place. Poor radiation performance of the coil will result in a potential safety hazard.     

Nb3Sn超导磁体低温冷却设计

介绍了聚变堆用Nb₃Sn超导磁体管内电缆导体（CICC)的结构型式和参数,以及超导磁体的运行工况,采用一维数学模型Gandalf对超临界氦迫流冷却回路进行压降计算,从理论上确定了较为合理的液氦质量流率。     

KTX反场箍缩装置主支撑结构设计与分析

KTX反场箍缩实验装置主支撑由柔性支撑和支撑平台组成,主要用来支撑真空室、导体壳和纵场线圈的重量。鉴于主支撑结构的重要性,通过有限元分析和理论分析相结合的方法对主支撑进行了强度分析和稳定性分析,给出了主支撑应力分布和变形情况及不同结构参数下的临界载荷。分析结果验证了主支撑结构的可行性,并为主支撑的后续优化设计提供理论依据。