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This paper aims to present the design and a prototype experiment of a robotic joint module for tokamak in-vessel manipulator-related research; the results will promote the adaptation of current in-vessel inspection manipulator to achieve full tokamak in-vessel environment compatibility.

A flexible metallic bellow-enclosed working chamber is used to protect the main servo drive components, the active cooling method for high temperature protection and the servo control structure simplification for high radiation endurance. A joint module prototype is manufactured and tested under a similar in-vessel environmental condition for extreme condition protection validation and basic servo control ability evaluation.

The joint module prototype successfully survived the similar in-vessel environment tests and proved good mobility via closed-loop servo control. A conceptual design of a serial linkage manipulator with joint module structure is proposed for future in-vessel inspection manipulator development.

The proposed joint module uses common industrial servo components to achieve its full extreme in-vessel environment compatibility. Different from traditional metallic bellow application in a vacuum environment to produce a linear movement result, the proposed joint module aims to achieve rotating movement directly from the metallic bellow structure, thereby reducing the joint structure space requirement, simplifying the vacuum environment movement transmission structure and increasing the vacuum environment compatibility degree.

This paper aims to present the design and experimental tests of an active circulating cooling system for the Experimental Advanced Superconducting Tokamak in-vessel inspection manipulator, which will help the current manipulator prototype to achieve a full-scale in-vessel high temperature environment compatibility.

The high-temperature effects and heat transfer conditions of the manipulator under in-vessel environment were analyzed. An active circulating cooling system was designed and implemented on the manipulator prototype. A simulative in-vessel inspection task in a high temperature environment of 100°C was carried out to evaluate the performance of the active circulating cooling system.

The proposed active circulating cooling system was proved effective in helping the manipulator prototype to achieve its basic in-vessel inspection capability in a high temperature environment. The active circulating cooling system performance can be further improved considering the cooling structure coefficient differences in different manipulator parts.

For the first time, the active circulating cooling system was implemented and tested on a full-scale of the in-vessel inspection manipulator. The experimental data of the temperature distribution inside the manipulator and the operating status of the circulating system were helpful to evaluate the current active circulating cooling system design and provided effective guidance for improving the overall system performance.

THE development of a shock tube by the Department of Aerodynamics and Space Technology commenced in September, 1961, and was completed towards the end of 1962. The shock tube and the shock tunnel will fulfil two functions. They will serve primarily as teaching facilities, with post graduate courses in view and will also be used as an advanced tool for staff research.

The purpose of this paper is to build up a parallel robot for assembling, machining and repairing of the vacuum vessel of the international thermonuclear experimental reactor (ITER).

The process of assembling and machining of the vacuum vessel need a special robot. By studying the structure of the vacuum vessel, a novel parallel robot is built, which has ten degrees of freedom driven by water hydraulic cylinders and electrical servo motors. Kinematic models for the redundant degree robot have been defined. A prototype has been built. Experiments for machine cutting and laser welding were carried out.

The parallel robot is capable of holding all necessary machining tools and welding end‐effectors in all positions accurately and stably inside the vacuum vessel sector. The kinematic models appeared to be complex because of the redundant structure of the robot, and an optimization algorithm ensuring the maximum stiffness during the robot motion helps to find the solution in the trajectory planning. The entire design and testing process of the robot appeared to be a very complex task due to the high specialization of the manufacturing technology needed in the ITER reactor, while the results demonstrate the applicability of the proposed solutions quite well.

Offers not only a device but also a methodology for the assembling and repairing of ITER by means of a parallel robot.

This paper aims to present a study on composite coating films for solid lubrication applied on the surface of bearings and gears, which are exposed to the vacuum vessel of a tokamak fusion experimental device running under ultra-high vacuum conditions. Experimental advanced superconducting tokamak is a tokamak fusion experimental device running under ultra-high vacuum conditions. To avoid polluting the inner vessel environment, solid lubrication has been applied on the surface of bearings and gears, which are exposed to the vacuum.

Anti-friction MoS₂ coatings integrated with Titanium and Carbon have been developed using the multi-target magnetron sputtering deposition technique. This paper presents the comparative testing of tribological properties for three kinds of MoS₂-based coating layers.

Based on the test results, MoS₂-Ti-C coating films are supposed to be the final selection because of the better performance of friction coefficient and lubrication longevity.

Finally, the detailed information has been characterized for the hybrid coatings, which can provide some references for applications of solid lubrications under similar conditions of high vacuum and temperature.

The purpose of this paper is to introduce a development and error modeling of a serial redundant manipulator system applied in nuclear fusion environment. Detailed mechanical design of vacuum-compatible arms and actuators are presented, and manipulator flexibility is studied through experiments and model identification algorithm to evaluate the deformation.

First, the manipulator is designed to be several modular segments to obtain enough and flexible workspace inside the fusion device with narrow and complex geometries. Joint actuators with “rotation-linear-rotation” chains are developed to provide both huge reduction ratios and vacuum sealing. The redundant manipulator system has 11 degree of freedoms in total with a storage cask system to dock with the device vacuum vessel. In addition, to improve the position accuracy, an error prediction model is built based on the experimental study and back-propagation neural network (BPNN) algorithm.

Currently, the implementation of the manipulator system has been successfully carried out in both atmosphere and vacuum condition. Excellent performance indicates that the mechanical design is suitable. The validation of BPNN model shows an acceptable prediction accuracy (94∼98 per cent) compared with the real measurement.

This is a special robot system which is practically used in a nuclear fusion device in China. It will allow remote inspection and maintenance of plasma facing components in the vacuum vessel of fusion device without breaking the ultra-high vacuum condition during physical experiments. Its design, mechanism and error prediction strategy have great reference values to the similar robots in vacuum and temperature applications.

HIGH vacuum engineering has made rapid strides within the last decade for applications within many branches of science and engineering, including metallurgy, general engineering, optics, cryogenics, electronics, and, of course, aeronautics and astronautics. It is the aim of this article to describe briefly the techniques involved in high vacuum engineering and to describe some of the equipment being produced by one of the British companies occupying a leading position in this field—Bir‐Vac Ltd.

The purpose of the present investigation is to compute the circulation flow of a liquid in a closed chamber when the liquid is fired by a gas jet through number of nozzles.

The conservation equations for mass and momentum have been solved in a closed container along with the conservation of volume fraction of the secondary phase in order to take into account the gas phase present in the liquid. The drag force created by the gas on the liquid has been incorporated in the momentum equation as a source term and the resulting equations have been solved numerically using a finite volume technique in an unstructured grid employing a phase coupled pressure linked velocity solver for the pressure correction equation, which is usually known as the Eulerian Scheme for two phase flow solution. An eddy viscosity based k‐ε turbulence model for the mixture was considered to update the fluid viscosity with iterations and capture the turbulence in the overall mixture rather than computing the individual turbulence in both the phases, which was found to be extremely time‐consuming and computationally unstable to some extent.

The model thus developed was tried to predict the circulation flow rate in an experimental setup where air was injected to drive the water in a long U tube setup. The computed circulation flow rate was found to be within 15 percent deviation from the experimentally observed values. The circulation flow rate of water was found to be increasing with the injected airflow rate. After this model validation, circulation flow rate of steel in an industrial size Ruhrstal‐Haraeus (RH)‐degasser was computed by injecting argon into the liquid steel through the up‐leg of the RH vessel. It was found that the circulation flow rate of steel in the RH degasser was increasing when the argon flow was being varied from 800 to 1,600 NL/min, which confirms the industrial findings.

The present computation could not use the energy equation to compute the swelling of the gas bubbles inside the chamber due to huge computing time requirement.

The present computation could compute realistically the circulation flow rate of water in a U tube when fired by a gas jet by using a two‐phase Eulerian model and hence this model can be effectively used for industrial applications where two‐phase flow comes into picture.

The original contribution of the paper is in the use of the state‐of the‐art Eulerian two‐phase flow model to predict circulation flow in an industrial size RH degasser.

In this paper, numerical modelling and dynamical response analysis were performed for the HL-2M vacuum vessel (VV) and shielding plates (SPs) during a plasma disruption by using an updated ANSYS parametric design language (APDL) code developed by the authors. The purpose of this paper is to investigate the influence of the SPs on the dynamical response of VV owing to a transient electromagnetic (EM) force and to optimize the design of SPs in view of the minimization of the structural dynamic response.

The Lagrangian approach, i.e. the moving coordinate scheme developed by the authors, was updated to tackle the EM-mechanical coupling effect in the dynamic response analysis of the VV-SPs system due to the transient EM force during plasma disruptions. To optimize the structural design of HL-2M SPs, the influence of the key parameters of SPs, i.e., the side length, thickness and material properties, was clarified on the basis of the numerical results and an optimized design of SPs was obtained.

The updated APDL code of the Lagrangian approach is efficient for the transient dynamical response analysis of the VV-SPs system owing to the EM force. The SP of a smaller side length, larger thickness tungsten material better mitigates the dynamical response of the VV-SPs system.

The Lagrangian approach was updated for the EM–mechanical coupling dynamical response analysis of the VV-SPs system, and the influence of the SP parameters on the dynamical response of the VV-SPs system of HL-2M Tokamak was clarified.