The Numerical Simulation Research Of Steam Heating Process Of Heated Mandrel Winding

The forming quality of composite shell depends mainly on manufacturing technology. The external curing method is usually adopted as traditional forming process of composite shell, which places the wound shell into the thermal compression reactor or the oven to cure. This process greatly limits the molding efficiency because winding and curing proceed respectively and separately. The internal curing method takes advantage of the structure of cylinder-shaped composite shell to solve the problem. It heats the mandrel with high pressure steam to realize the in-situ curing of the wound shell, which greatly shortens the process time, decreases the complex degree of the technology and improve the molding efficiency.Although, the successful utilization of internal curing in engineering provides referential thinking for heated mandrel curing, and these two technologies have many in common, the heated mandrel curing process has many unsolved problems. For example, the uneven mandrel temperature causes the stratification phenomenon of the shell, realizing the low control temperature by high temperature is totally based on experience, etc. Therefore, deeper research of basic theory on heated mandrel curing needs to be performed.This paper introduces the process principle of the heated mandrel winding of the filament wound composite shell. The physical model of the mandrel and the steam inside is set up, and the mathematical model of the flow and heat transfer process is established. The numerical simulation is carried out by using the finite element fluid analysis software FLUENT. The simulation result shows the distribution and changing course of the multi-physical fields of the mandrel temperature, steam temperature and steam flow. By analyzing the result, the relationship between the distributions and changing courses of the mandrel axial temperature and the pressure, temperature and velocity of steam and the parameters of steam control and mandrel structure is obtained. The mandrel structure is improved according to the conclusion, and the experiment of comparison between the pipes made by improved mandrel and traditional mandrel. The experiment results shows that the improved mandrel improves the performance of the pipes to some extent. The research provides theoretical basis for the realization of the heated mandrel winding process and the parameter optimization of steam control and mandrel structure.