Heat transfer simulation and analysis of mandrel for heated-mandrel winding method of tapered shell

With the advantages of high production efficiency and good product quality, the heated-mandrel winding method has been widely used for high-pressure shells. Previous research results show that it is very important to ensure that the axial temperature is distributed as expected because the temperature distribution influences shell-forming qualities to a large extent. In contrast to cylindrical shells, tapered shells have not only a tapered mandrel but also uneven thickness of the shell, so the internal structure of currently used mandrels cannot achieve the desired temperature distribution. The finite element model of the temperature field and flow field of the steam inside the mandrel of tapered shell using the standard k-e formula and the steam-heating process for mandrels with tapered shells is simulated using FLUENT. The results of the numerical simulation show the temperature, velocity, and pressure of the model. According to this, the flow and heat transfer characteristics of steam are analyzed to reveal the influences of process parameters and runner structure on the internal temperature distribution of the mandrel. By considering the influences of inlet pressure, hole positions, and hole diameters, the relationship between the temperature distribution of the surface of the mandrel and the process and the mandrel structure parameters are discussed. The conclusions provide the theoretical basis for the optimization of the mandrel structural design and the heated-mandrel winding method.