为一个球形中空塑料制品的滚塑成型工艺的加热阶段建立了一种新的流动与传热理论模型，并采用Fluent软件对其进行数值计算。该理论模型将模具的导热、塑料层的导热和随后的熔融以及内部空气的自然对流换热耦合起来求解。数值计算所得的加热时间、模具外壁面温度和内部空气温度都与实验结果吻合较好，从而证明了本理论模型的有效性。最后采用该理论模型分别计算了在不同外部加热温度、外部对流换热系数以及塑料粉末层厚度下的加热时间，从而确定了这些参数对加热时间的影响，并得出了提高外部对流换热系数比提高外部加热温度能更有效地缩短加热时间等结论。%A new flow and heat transfer theoretical model was established for heating phase of rotational molding process for spherical hollow plastic parts, and numerical computation was performed by means of Fluent software based on the model. Heat conduction of mold, heat conduction of plastic layer and following melting, and convective heat transfer of internal air were coupled for the solution of the model. Heating time, temperature at outer wall of mold and temperature of internal air obtained by numerical computation were in good agreement with those by experiment, and thus the theoretical model was validated. In addition, heating time under different outer heating temper- atures, outer convective heat transfer coefficients, and plastic layer thicknesses were calculated so that effects of these parameters on heating time can be determined. And some conclusions were made, such as increasing outer convective heat transfer coefficient could shorten heating time more effectively than raising outer heating temperature.
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