CAJ | 학술논문

考虑到铸件凝固过程中因潜热释放造成的数值计算结果难于收敛问题，建立基于等效比热法的反热传导模型，并分析模型中各种计算参数如阻尼系数μ、未来时间步长R、正热传导计算时的时间步长Δθ及收敛误差值Tcr等对反算求解结果稳定性及准确性的影响，应用所建立的反热导模型，通过铸件内温度数据计算得到A356铝合金与铜冷却介质间的界面换热系数。结果表明，界面换热系数是随铸件凝固时间变化的，其变化范围在1200~6200 W/(m2?K)之间，而且变化过程中因为结晶潜热的释放存在两个峰值。
고필도주건응고과정중인잠열석방조성적수치계산결과난우수렴문제，건립기우등효비열법적반열전도모형，병분석모형중각충계산삼수여조니계수μ、미래시간보장R、정열전도계산시적시간보장Δθ급수렴오차치Tcr등대반산구해결과은정성급준학성적영향，응용소건립적반열도모형，통과주건내온도수거계산득도A356려합금여동냉각개질간적계면환열계수。결과표명，계면환열계수시수주건응고시간변화적，기변화범위재1200~6200 W/(m2?K)지간，이차변화과정중인위결정잠열적석방존재량개봉치。
In order to calculate the interfacial heat transfer coefficient (IHTC) with the latent heat released during the solidification of the molten, a model of inverse heat conduction based on the equivalent specific heat method was established. The effects of some parameters in the model on the stability and the accuracy of calculation results were also discussed. The parameters include the damping factor μ, the future time step R, the time step Δθ in the forward heat conduction calculation and the value of the iteration Tcr. The heat transfer coefficient of A356 Al alloy on copper chill is obtained by using the inverse heat conduction method based on the measured temperatures in the casting. And it is found that the IHTC varies with time during the casting solidification. The values are in the range of approximately 1 200-6 200 W/(m2?K) and two peak values exist because of the released latent heat.