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In-depth analysis of the pressure profile of coating beads of slot die coating is helpful to better understand the behavior of the flow field in a coating bead and to better obtain a stable coating bead. In this study, ANSYS Fluent 19.2 was used to simulate slot die coating. The simulation results clearly show the influence of various operating parameters on the state of the coating bead and the pressure profile in the coating bead. The results show that the pressure profile can be clearly changed by changing the flow rate, substrate speed, and downstream die lip length. Simultaneously increasing the substrate speed from 0.08 to 0.12 m/s and the average inlet velocity from 0.02672 to 0.04 m/s results in an increase in maximum pressure from 298 to 538 Pa. Increasing only the substrate speed, from 0.12 to 0.16 m/s, causes the maximum pressure to decrease from 538 to 195 Pa. Increasing only the average inlet flow velocity, from 0.027 to 0.04 m/s, leads to an increase in maximum pressure from 167 to 745 Pa. Extending the downstream die lip length from 0.4 mm to 1 mm results in an increase in maximum pressure from 189 to 471 Pa. Reducing the upstream coating gap from 0.3 to 0.1 mm results in significant changes in the pressure profile in the upstream direction. Changing the contact angle can affect the pressure profile in the coating bead, but this is not clear. Changing the coating liquid density at a Reynolds number less than 1.733 has less effect on the pressure profile. [ABSTRACT FROM AUTHOR]

This paper presents an iterative stress wave log beam imaging algorithm based on external shape to predict the size, shape, and position of internal features in logs. The algorithm's accuracy is analyzed to establish a theoretical and scientific basis for the prediction and evaluation of internal knots in standing trees. Six sample logs with natural knots were selected for study, and cross-sectional stress wave propagation tests were conducted using FAKOPP to collect data. Using the shortest propagation path method, the algorithm iteratively produced fault images of the log cross-sections. While the algorithm can roughly predict the location of internal features, discrepancies between predicted and actual shapes and sizes result in relative errors ranging from 15.66% to 52.08%. Except for sample log 6, the relative error for other logs is mostly within 31%, with logs 1, 2, and 5 showing errors under 20%. However, the imaging accuracy and effectiveness need improvement. Further experimental studies and algorithm enhancements are necessary to improve fault imaging and prediction accuracy, particularly in terms of shape and size precision. [ABSTRACT FROM AUTHOR]

The structural design is a prerequisite for the creation of mechanical equipment. This study focuses on the structural synthesis of epicyclic chains (ECs), and proposes a new topological model and synthesis method of ECs to address the existing research problems (i.e. synthesis dependence on multiple graphic transformations and the generation of pseudo-isomorphism). First, the structural characteristics of ECs are analyzed to explore the relation between their axles, gears, and planet carriers, and the corresponding topological model and the adjacency matrix expression of ECs are provided. Then, the topological elements corresponding to the axles, gears, and gear pairs are added sequentially to the topological graph corresponding to the planet carriers, and the constraints are established based on similarity to inhibit the generation of isomorphism. Finally, all the databases of feasible ECs are obtained through gear loop discrimination. All processes are carried out with computer assistance. The synthesis results of the ECs with 1–3 degrees of freedom and up to 10 components are presented. The logic of this paper is to simplify (or optimize) the synthesis process to improve efficiency of structural synthesis, which will break through the threshold of computing power and provide more possibilities for the design of mechanical equipment. [ABSTRACT FROM AUTHOR]