On the Newtonian Thermal Analysis of Casting: a Critical Aproach

Abstract

One of the primary aims of Newtonian thermal analysis (NTA) is the prediction of latent heat and finding solid fraction. When the prediction is made, Newtonian baseline (NBL) is computed, and the difference to experimental cooling rate curve is analyzed. In this study, it was seen that NBL calculations had some contradictions and that latent heat calculations gave high errors. After determining these contradictions, a new method, called one-capacitive-system baseline (OCSBL), was developed by gathering the solution advises to each other. Cooling curve of mold-insulated pure Tin was analyzed by both methods to test them. It was seen that OCSBL predicted the latent heat better than NBL when the results were compared with the literal values.

Keywords

• Newtonian thermal analysis, solid fraction, latent heat

METAL DÖKÜMLERİNİN NEWTON SALISI ANALİZİ ÜZERİNE: ELEŞTİREL BİR YAKLAŞIM

Abstract

Döküm için Newtonsal ısı analizinin başlıca amaçları arasında ergime ısısı tahmini ve katı kesrinin bulunması gelmektedir. Bu tahmin yapılırken Newton taban eğrisi (NTE) hesaplanıp deneysel soğuma eğrisi arasındaki fark analiz edilmektedir. Bu çalışmada, Newton taban eğrisi hesaplamanın bazı çelişkileri barındırdığı ve ergime ısısı hesaplarının yüksek hatalar verdiği görüldü. Bu çelişkiler tespit edildikten sonra, her birine getirilen çözüm önerileri derlenerek, tekli-kapasitif-sistem taban eğrisi (TKSTE) adında yeni bir yöntem geliştirildi. İki yöntemi test etmek için, kaptan yalıtılmış saf kalayın soğuma eğrisi iki yöntemle de analiz edildi. Sonuçlar literatürdeki termal değerler ile kıyaslandığında, TKSTE nin NTE den daha iyi ergime ısısı tahmin ettiği görüldü.

Keywords

• Termal Analiz, Ergime Isısı, Katı Kesri

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