(1. 中南林業(yè)科技大學 機電工程學院，長沙 410004；
2. 湖南大學 汽車車身先進設(shè)計與制造國家重點實驗室，長沙 410082)
摘 要: 考慮到鑄件凝固過程中因潛熱釋放造成的數(shù)值計算結(jié)果難于收斂問題，建立基于等效比熱法的反熱傳導模型，并分析模型中各種計算參數(shù)如阻尼系數(shù)μ、未來時間步長R、正熱傳導計算時的時間步長Δθ及收斂誤差值Tcr等對反算求解結(jié)果穩(wěn)定性及準確性的影響，應(yīng)用所建立的反熱導模型，通過鑄件內(nèi)溫度數(shù)據(jù)計算得到A356鋁合金與銅冷卻介質(zhì)間的界面換熱系數(shù)。結(jié)果表明，界面換熱系數(shù)是隨鑄件凝固時間變化的，其變化范圍在1 200~ 6 200 W/(m2？K)之間，而且變化過程中因為結(jié)晶潛熱的釋放存在兩個峰值。
關(guān)鍵字: A356鋁合金；凝固潛熱；等效比熱法；反熱傳導；界面換熱系數(shù)
（1. College of Mechanical and Electrical Engineering,
Central South University of Forestry and Technology, Changsha 410004, China;
2. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,
Hunan University, Changsha 410082, China）
Abstract: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.
Key words: A356 Al alloy; latent heat released; equivalent specific heat method; inverse heat conduction; interfacial heat transfer coefficient
