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为研究丁羟推进剂浇注过程中流场结构,使用改进后的Herschel-Bulkley黏度模型对药浆花板浇注过程进行了数值模拟,并与实验数据进行了对比。结果显示:在通过花板孔后药浆会发生汇流,汇流后的药浆在重力作用下在发动机壳体内堆积,堆积表面呈现不规则的凹凸状,但在重力作用下,药浆会逐渐流平并填满空腔,未形成空洞。被花板分割的药条一部分汇聚后沿翼片间凹槽向下流动,一部分直接向下流动,流动过程中出现拉伸断裂的现象。浇注所需总时间为104 min,浇注药浆总质量为160.3 kg,平均质量流率为5.4 g·(hole·min)-1,仿真计算值与实测值误差分别为8.65%、2.06%和5.93%。 相似文献
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In this paper, we use femtosecond laser pulse to scribe 304 stainless steel foil, detect the Fourier transform infrared spectrum of the sample before and after processing, confirm the "cold processing" and "thermal processing" and their mutual conversion, and determine the "cold processing" parameter window. The ablation threshold and incubation coefficient of 304 stainless steel foil are calculated, and the effects of scanning speed and effective pulse number on the ablation threshold are analyzed. The ANSYS software is used to simulate the radial and axial temperature distributions of the surface on 304 stainless steel foil sample and the heat-affected zone with a femtosecond laser fluence of 10 J/cm2 and an effective number of pulses of 1 200 are obtained. In the aspect of spectral detection, the Fourier transform infrared spectra of the sample before and after processing are measured and two processing mechanisms of "cold processing" and "hot processing" are confirmed, which proves that we can achieve the conversion between "cold processing" and "hot processing" by changing the laser fluence and determine the "cold processing" laser fluence range. 相似文献
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