摘 要
在鑄造行業(yè)中，型砂性能對鑄件的質(zhì)量和廢品率有一定影響，型砂性能主要是指型砂的溫度、強(qiáng)度、緊實率和水分等。其中，型砂溫度對鑄造的影響較大，型砂溫度過高對鑄造帶來很多危害。本文基于對熱砂在儲砂柜中冷卻的傳熱過程理論分析，結(jié)合強(qiáng)化傳熱方法，研究舊砂冷卻循環(huán)過程中型砂置于儲砂柜中的冷卻過程，尋求合理的冷卻方式和儲砂柜結(jié)構(gòu)形式。
本文采用以下幾種強(qiáng)化冷卻手段進(jìn)行模擬分析：⑴儲砂柜外表面加針肋；⑵儲砂柜外加套筒；⑶改變針肋排列方式；⑷采用熱管強(qiáng)化；⑸結(jié)合針肋與套筒；⑹在套筒進(jìn)風(fēng)口加風(fēng)機(jī)。前兩種方式是對儲砂柜進(jìn)行初步試驗?zāi)M分析，后四種方式是對儲砂柜模型的優(yōu)化，以尋找一種更合理的強(qiáng)化冷卻措施。
對儲砂柜的傳熱數(shù)值模擬是本文的主要研究手段，通過有限元分析軟件建立不同的三維儲砂柜模型并進(jìn)行氣-固耦合數(shù)值模擬。對模擬結(jié)果分析得出，最終時刻熱型砂內(nèi)最高溫度值及時間-溫度曲線，從而判斷不同方式的冷卻效果。
研究結(jié)果表明：外加套筒的儲砂柜結(jié)構(gòu)對型砂的冷卻較明顯，而且制造成本低；熱管強(qiáng)化的儲砂柜結(jié)構(gòu)對型砂的冷卻效果更明顯，但制造成本較高。
本文依據(jù)相似理論還針對兩種簡單砂柜模型進(jìn)行了實驗方案設(shè)計，建立相似模型，確定實驗及數(shù)據(jù)整理方法，為后續(xù)實驗研究提供理論依據(jù)。

關(guān)鍵詞：儲砂柜；強(qiáng)化傳熱；數(shù)值模擬；相似理論







Abstract
In the foundry industry, the performance of sand has a great impact on the quality and defective index of casting. The performance of sand mainly refers to its temperature, intensity, compactability and moisture. Among them, the sand temperature has the greatest impact on the casting. High temperature of sand can bring lots of harm to casting. The paper is to find a model of sand that is suitable for cooling sand, combining with enhanced heat transfer method, based on the theoretical analysis of heat transfer process of sand cabinet.
This paper is based on the casting sand cooling related knowledge，from the casting sand cooling heat transfer principle，firstly simulate natural cooling heat transfer effect of sand cabinet，then looking for some reasonable cooling system. Through the contrast analysis, explain the selected cooling methods in theory. We can reach the highest temperature inside of sand and time-temperature in order to determine the effect of cooling. Establish similar model of sand cabinet then sort out the experiment data according to similarity theory, which provides a theoretical basis for latter experimental analysis.
In this paper, the following method of enhanced heat transfer is mentioned in the simulation analysis: (1) Needle rib added on the outer surface of the sand storage cabinet. (2) Sleeve added on the outer of the sand storage cabinet. (3) Changed arrangement of needle rib. (4) Using the heat pipe. (5) Combining sleeve with needle rib. (6) Adding fans to inlet of the sleeve. The first two methods above are used to have the preliminary test simulation analysis, and the latter four methods are to optimize the model of sand storage cabinet, which is to find a more reasonable measure of cooling sand temperature.
The focus of this study is on the numerical simulation of heat transfer. Establish a different three-dimensional model of sand storage cabinet by finite element analysis software, then carry out numerical simulation analysis of gas-solid coupling. We can reach the highest temperature inside of sand and time-temperature in order to determine the effect of cooling.
The results show that the cooling effect of the sand storage cabinet with is obvious and its cost is low; the cooling effect of the sand storage cabinet with heat pipe is more obvious but higher costs.
There is an experimental design of two simple model of sand cabinet by similarity theory in this paper. Establish similar model of sand cabinet then sort out the experiment data according to similarity theory, which provides a theoretical basis for latter experimental analysis.

Keywords: sand storage cabinet; enhanced heat transfer; numerical simulation; similarity theory.





目 錄
摘 要 I
Abstract III
第1章 緒論 1
1.1 課題研究背景 1
1.2 國內(nèi)、外研究現(xiàn)狀 3
1.2.1 型熱性能研究現(xiàn)狀 3
1.2.2 型砂冷卻方式研究現(xiàn)狀 3
1.3 本課題研究的意義 5
1.4 本文研究的主要內(nèi)容及方法 7
第2章 砂柜傳熱理論分析 9
2.1 砂柜的熱分析 9
2.1.1 熱分析類型的確定 9
2.1.2 熱傳遞方式 10
2.2 耦合場的概念及作用 12
2.2.1 耦合場的概念 12
2.2.2 耦合場的作用 13
2.3 自然對流的概念及研究現(xiàn)狀 13
2.3.1 自然對流的概念 13
2.3.2 自然對流研究與發(fā)展現(xiàn)狀 15
2.4 強(qiáng)化對流換熱的方式 16
2.5 本章小結(jié) 17
第3章 砂柜數(shù)學(xué)物理模型的確定 19
3.1 計算方法的選擇 19
3.1.1 有限差分法 19
3.1.2 有限元法 19
3.1.3 有限體積法 20
3.1.4 有限分析法 20
3.1.5 邊界元法 20
3.2 砂柜數(shù)學(xué)模型的建立 21
3.2.1 有限元分析軟件簡介 21
3.2.2 控制方程 23
3.2.3 流體模型 24
3.3 砂柜物理模型的建立 26
3.3.1 三維實體固體模型的建立 26
3.3.2 三維流體模型的建立 27
3.4 模型假設(shè) 28
3.5 本章小結(jié) 28
第4章 砂柜模型的數(shù)值模擬計算 29
4.1 單元類型選擇 29
4.2 網(wǎng)格劃分 29
4.2.1 固體模型網(wǎng)格劃分 30
4.2.2 流體模型網(wǎng)格..