导流管中液态金属热传输的数值分析

应用有限差分地喷射成形导流管中的液态金属的流场进行模拟，计算液态金属Ｆｅ，Ａｌ，Ｚｎ在不同过程参数条件下所需的最小过热度△Ｔ，得出了最小过热度和材料热物理性质及过程参数之间的半定量关系，计算结果表明，对于最小过热度，导流管的导热能力是最重要的影响因素，在常规使用的过压范围内，增大过压可显著上过热度，导流管的构形设计也是一关键因素，缩小导流管长度直径比Ｌ／Ｄ使△Ｔ减小，且对一坑熔点金属或高导热能力的

Numerical Analysis for Heat Transfer of Liquid Metals in Delivery Tube

A finite difference method is adapted to simulate liquid metal flow in deliv-ery tube of spray forming. Numerical calculations of minimum superheat, (which is neededto avoid delivery tube blockade due to metal premature solidification), are conducted fordifferent liquid metals (Fe, Zn, Al ), and process parameters. A semi-quantitative correla-tion is derived. Based on the calculated results, for the minimum superheat, the heatconductivity of delivery tube is the most imortant factor, a inapppropriate selection of tubematerials will cause superheat beyond permission; increasing overpressure also candecrease minimum superheat significantly; the other critical factor is the design of deliverytube configuration, reducing the length / diameter ratio (L/D) can decrease minimum super-heate, specially for metals with high melting point or delivery tube with high thermalconductivity.