Autoclave is a large horizontal pressure vessel, which is widely used in industries that require high temperature or pressure production process, such as heavy metal smelting, refractory brick immersion coal infiltration, heating or cooling of composite glass, cable vulcanization, medicine, aerospace industry, insulation materials and military industries, etc. Due to the particularity of the process conditions, the flow-field characteristics in the autoclave and the uniformity of temperature-field changes have a very important influence on its working performance.
As the application scenarios and actual working conditions of the autoclave have become more and more complicated, its internal flow-field characteristics and temperature-field characteristics have become the focus of research by experts and scholars. Li et al. [
1,
2] simulated the three-dimensional heat transfer and fluid flow in an autoclave with a length-to-diameter ratio of 10 under nonuniform heating conditions and analyzed the influence of baffles on the fluid flow characteristics in the autoclave. Bohne et al. [
3] studied the heat transfer in a small experimental autoclave through calorimeter measurements and fluid dynamics models and observed a complex turbulent flow pattern with a locally varying heat transfer coefficient. Schimmel et al. [
4] conducted machine-learning-related research on the fluid-flow and temperature-field simulation of autoclave. Zhang et al. [
5] established a simulation method of the flow field and temperature field in the working process of the autoclave through Xflow software and analyzed the influence of the process parameters of the autoclave on its internal flow field and temperature field. Appa et al. [
6,
7] studied the mass transfer process of the fluid in the autoclave by numerical simulation and verified it based on experimental data. They found that the mass transfer process of the fluid in the autoclave was poor and proposed an estimate empirical formula for fluid mass transfer based on the experimental data. Li et al. [
8] studied the turbulent motion characteristics of the fluid in the semicircular tube jacket on the inner wall of the autoclave by numerical simulation and studied the effect of the average Reynolds number Re, δ and τ on the velocity field and flow resistance of the fluid in the jacket. At the same time, the average axial velocity and the secondary flow function distribution of the fluid in the jacket were obtained based on the orthogonal spiral coordinate system. Antonucci et al. [
9,
10] analyzed the heat transfer phenomenon that occurred during the operation of the autoclave and compared it with experimental data from industrial autoclaves; they also conducted extensive tests on the semi-theoretical method developed. Gao et al. [
11] analyzed the flow-field characteristics and temperature rise process in the effective area of the autoclave through numerical simulation methods and verified the accuracy of the simulation through physical experiments. Li et al. [
12] studied the flow field and temperature field of the fluid in the autoclave based on the autoclave molding simulation software and optimized the position of the components in the autoclave, thereby improving the efficiency of process design and improving the quality of components operation. Kluge et al. [
13] predicted the temperature distribution of various parts in the autoclave by using computational fluid dynamics methods and compared the consistency of the prediction results with experimental data. It was found that more detailed inlet velocity curves and more advanced turbulence models may produce better consistency with experimental data. Jimmy et al. [
14] used the particle image velocimetry method to qualitatively measure the flow characteristics of the fluid in the autoclave. At the same time, they studied the heat transfer of the fluid in the autoclave by measuring the temperature at multiple locations during the heating process. Hassim [
15] studied the flow pattern of the autoclave through the Fluent software, and the results showed that the air flow velocity in the rear area of the autoclave was relatively uniform. Booth et al. [
16] studied the Reynolds number flow in the pipeline in the autoclave and studied the corresponding turbulent energy dissipation rate. Meng [
17] analyzed the influence of the length of the specimen in the autoclave on the influence of the fluid turbulence intensity and turbulent kinetic energy on its side by numerical methods and obtained that the optimal length of the specimen was 126 mm. Antonucci et al. [
18,
19] proposed a new method to analyze the heat transfer in the autoclave. The method has been applied to patch wing panels and was validated by comparison with the experimental data. Ghamlouch et al. [
20] designed and manufactured an autoclave model based on the law of similarity, which allows the use of PIV technology to measure the flow field around a representative real industrial molding and to characterize the heat transfer with the help of a thermal imager. Bhatti et al. [
21] recounted the latest trends in computational fluid dynamics in an editorial. In addition, some scholars have studied the characteristics of other fluid peristaltic flows [
22,
23,
24] and temperature fields [
25,
26], which has certain reference significance for the selection and setting of simulation models and boundaries [
27,
28]. The flow-field characteristics and temperature-field characteristics in the autoclave have been studied above, but the research on the flow-field characteristics in the guide channels in the autoclave is rarely involved.
The autoclave studied in this paper is mainly used for heating and cooling composite glass. The uniformity of the air inlet flow of each guide channel in the autoclave and the velocity characteristics of the air at the outlet of the guide channels have a very important influence on the overall flow-field characteristics and temperature-field distribution characteristics in the autoclave. Therefore, in order to solve the problem of uneven air inlet flow in each guide channel in the autoclave, three optimization schemes for the guide plate are proposed. Quantitative and qualitative analysis is performed on the air inlet flow characteristics of the guide channels in the autoclave and the velocity characteristics at the outlet of guide channels under each optimization scheme to measure the optimization effect. The research results provide a certain reference for the design and optimization of the guide-plate structure in the relevant autoclave.