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用水模、各种实验技术和数学模拟研究了板坯结晶器中湍流的结构。弯月面稳定性取决于结晶器内湍流结构;用k-ε模型与雷诺切应力模型(RSM)做的数学模拟表明:在给定拉坯速度下,雷诺切应力模型能更好地预测弯月面轮廓。用粒子图像测速技术测得的雷诺切应力和流动涡旋状态与雷诺切应力模型预测的雷诺切应力和流动涡旋状态非常接近,并报道了横穿射流直径的最大值与最小值。浸入式水口出口上端的回流取决于拉坯速度,且随着拉坯速度提高而消失。低拉速时,报道了射流没有足够的能量耗散,所以上流辊能达到浸入式水口出口处。高拉速时,射流能量在浸入式水口孔内,结晶器窄边和结晶器拐角处耗散强烈,减弱了上流辊的动量传输,上流辊不能到达浸入式水口出口处。低拉速时,观察到弯月面的不稳定发生在结晶器拐角处。报道了弯月面完全稳定的最优拉坯速度。高拉速时,自由表面的流动结构显示为一个有较大速度梯度的岛状复合结构。这些速度梯度是造成弯月面不稳定的原因。
The structure of turbulent flow in slab mold was studied by using water model, various experimental techniques and mathematical simulation. The meniscus stability depends on the turbulent structure in the mold. Mathematical simulations with the k-ε model and the Reynolds stress model (RSM) show that the Reynolds stress model can predict the bending better at a given casting speed Moon contours. The Reynolds stress and the flow vortex state measured by the particle image velocimetry technique are very close to the Reynolds stress and the flow vortex state predicted by the Reynolds shear stress model and the maximum and minimum values of the transverse jet diameter are reported. The backflow at the upper end of the submerged entry nozzle depends on the casting speed and disappears as the drawing speed increases. Low draw speeds reported that the jet did not have enough energy to dissipate, so the upper roll could reach the exit of the immersion nozzle. At high draw speeds, the jet energy is dissipated strongly in the submerged nozzle hole, the corners of the mold narrow and the corners of the mold dissipate strongly, weakening the momentum transfer of the upper roll and the upper roll can not reach the outlet of the immersion nozzle. At low draw rates, it was observed that the meniscus instability occurred at the corners of the mold. Reported the perfect stability of the meniscus the best casting speed. At high draw speeds, the free-surface flow structure appears as an island-like composite structure with a greater velocity gradient. These speed gradients are the cause of the meniscus instability.