| Summary: | The secondary cooling of AZ80 during DC casting was investigated by measuring the temperature at a given position during steady state. The experiment was carried out under different parameters including the water flow rate density (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>Q</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula>) and initial temperature (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>T</mi><mi>i</mi></msub></mrow></semantics></math></inline-formula>) of the impingement points. To theorize the heat transfer of the secondary cooling zone in practical DC casting, we designed a series of experimental equipment to simulate the secondary cooling with differing <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>T</mi><mi>i</mi></msub></mrow></semantics></math></inline-formula> (between 473 and 673 K) and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>Q</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula> (between 20 and 100 L min<sup>−1</sup> m<sup>−1</sup>) based on the DC casting temperature-measurement experiment above. Detailed analysis was carried out of both the experimental results combined with <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>Q</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula>. The empirical formulae of Rohsenow and Weckman were modified due to the need to divide the secondary cooling zone into an impingement zone and a free-falling zone. Finally, a verification of the model’s accuracy was conducted by comparing the results of the finite volume numerical simulation and the experiment, which revealed that the model exhibited extremely high accuracy.
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