Papers by Keyword: Temperature Field

Abstract: Taking efficient pumping-unit linear motor as the research object in this paper, SOLIDWORK has been used to establish 3D model and analyze multi-physics of the efficient pumping-unit linear motor, including vibration mode, stress analysis and the analysis of temperature field. Through the simulation analysis, getting efficient pumping unit linear motor of the top five order vibration frequency, pressure distribution and temperature distribution, theoretical references are provided for the analysis of the efficient pumping-unit linear motor. The innovation of the article is in coupling analysis of multi-physics.

Abstract: The generation of heat source of high efficiency linear pumping unit was analyzed. The calculation method of motor loss and heat dissipation coefficient was given. The finite element analysis software was used to simulate and analyze the temperature field of the linear pumping unit in the phase of constant motion and the starting and reversing phase. According to the analysis, it was concluded that the reasonable optimization of linear motor cooling structure can ensure the good temperature characteristics.

Abstract: During the laser cladding process, temperature field is an issue worth thorough research. An optimized temperature field can not only ensure the high metallurgical bonding strength between the cladding layer and the substrate, but also can produce relatively mild thermal deformation for the parts to be repaired. This work theoretically analyzes the temperature field during the cladding process and validate the analysis through the microstructure of the cladding layer.

Abstract: A concept of heterogeneous welded joint is proposed for researching and describing the characteristics of local postweld heat treatment (PWHT) temperature field for asymmetric thermal conductivity welded joint. Its three types have been classified according to thermal conductivity direction around the weld, separately, welded joint with transverse unidirectional thermal conductivity, transverse bidirectional thermal conductivity, transverse and longitudinal thermal conductivity. Compared with the temperature field of symmetric thermal conductivity welded joint, the highest temperature point of heterogeneous welded joint deviates from the heat device center, and uniform temperature area shrinks. In addition, longitudinal temperature difference and dramatic temperature change zone have arisen for the third type heterogeneous welded joint. In order to improve the temperature distribution, two PWHT methods called temperature compensation method and power compensation method have been put forward and developed. Several engineering applications of two methods are illustrated as examples.

Abstract: Backing plate has an important influence on the temperature field of workpiece during the friction stir welding process. In order to predict the temperature field of workpiece accurately, a thermal-fluid coupled friction stir welding calculation model including workpiece and backing plate was developed. In the model, an equivalent film method was proposed to simplify the contact heat transfer between workpiece and backing plate to a heat conduction problem. The computational fluid dynamic software FLUENT was ultilized to simulate the friction stir welding process of 2A14 aluminum alloy. As a result, the steady-state temperature field during the friction stir welding process was predicted and analyzed. The welding process test was carried out to verify the simulation results of temperature field. The compared results show that the simulated temperature and the measured values of all measuring points are in good agreement. Using the simulation method proposed in this paper, the calculation accuracy of temperature field during the friction stir welding process could be relatively high and the maximum error is 4.61%. In addition, there is a good corresponding relationship between the temperature distribution and the various regions of weld cross section.

Abstract: The application of functional layers has increased constantly over the last decades [1]. Coating processes like plasma spraying allow efficient processing of metal or oxide particles, and have already found their application in various sectors of industries. Ultra fine cleaning, surface activation or surface modification with the plasma arc are currently also under investigation. In the scope of this work the influence of four different main parameters - current, working distance, feed speed and gas flow - on the arc temperature field was investigated. Due to the complex and different interactions of these parameters on the temperature field, the temperature distribution in steel and aluminium sheets was systematically examined. Furthermore, the relationship between the measured surface temperatures and the wettability of the substrates is being discussed. To generate the required data, two different experimental setups were used. First, the spatial heat distribution of the plasma arc was measured with a special arrangement of thermocouples. Second, the temperature fields during the plasma surface treatment of DC01 and Al 6082 substrates was measured. In addition to measurements with NiCr-Ni thermocouples an investigation with an IR-Camera was performed. After the plasma surface treatment, the resulting wettability was determined by contact angle measurement. The obtained results and especially the measured temperature fields will be used in a next step to validate numerical simulations with SYSWELD and ANSYS CFX, which will be used for process optimization.

Abstract: Surface integrity of workpiece, especially residual stress, has the significant effects on the precision, the reliability and the fatigue life of the mechanical products. Since the most of final surface integrity of workpiece depends on the grinding process in engineering, this paper analyzed the ground surface residual stress through simulation and experiment. Based on the finite element model, the coupling of thermal mechanical field of plane grinding was simulated. The effects of grinding parameters on residual stress were studied compared to the experiment results. In addition, some measures for reducing the residual tensile stress of workpiece surface in the grinding process were put forwarded.

Abstract: During the dressing process of diamond wheel using laser/ultrasonic-vibration combined dressing method, the removal mode of the local materials on the surface of wheel with the use of laser’s heating effect transits from brittle fracture to plastic flow, so that the wear of diamond dresser can be reduced and the dressing efficiency and surface dressing quality can be improved. Using ANSYS analysis software, the three-dimensional units were used and the nonlinearity of the material’s thermophysical properties was taken into account, and thereby, the finite element model of the temperature field of the diamond wheel heated by the laser during the dressing process was constructed. Then, the distributions of the temperature field on the surface and section of the wheel under different technological parameter were acquired. Moreover, the temperature distribution of the dressed wheel under actual working conditions was measured using infrared temperature measurement method. The results indicate that, under the same working conditions, the simulation results using finite element model fit well with the measured values, i.e., the finite element model has important guiding significance to the selection of technological parameters in dressing.

Abstract: The model of laser sintering with regard to explicit porosity evolution of powder layer has been suggested. Due to porosity reduction the shrinkage occurs, thermal - physical properties (the heat capacity, thermal conductivity coefficient) and reflection coefficient of laser irradiation change. It has been shown that additional mechanism of convective heat transfer connects with powder layer thickness evolution. It was detected that model obeys some prognostic properties and allows to reveal the area of technological parameters where homogeneous properties of sintered layer form.

Abstract: This paper uses ProCast software to simulate Mg-Gd alloy solidification process, calculates temperature field and solidification field for Mg-9.76Gd at different stages and compares the influence of different heat transfer coefficient on the solidification structure. The results show that the crystallization process which is simulated is consistent with the actual crystallization process; as the heat transfer coefficient increases, the average grain size decreases. With the result, the reasonable casting formation control parameters can guide the practical production, which can reduce human and financial resources.