Based on the similarity theory, taking the horseshoe, city-gate and round linings as examples, the value and distribution regularities of normal frost heaving pressures （hereinafter as frost heaving pressures） in tu...Based on the similarity theory, taking the horseshoe, city-gate and round linings as examples, the value and distribution regularities of normal frost heaving pressures （hereinafter as frost heaving pressures） in tunnels excavated in fractured rock mass in cold regions under different constraints and freezing depths were studied by a test model. It was found that the larger the frozen depth, the larger the frost heaving pressure, and the stronger the top constraint, the larger the frost heaving pressure. For the horseshoe lining and city-gate lining, the top constraint has a greater effect on the frost heaving pressures on the arch and the inverted arch. For the round lining, the influences of the top constraint on the frost heaving pressure in all linings are almost the same. The frost heaving pressure is maximum on the city-gate lining and minimal on the round lining. The largest frost heaving pressure all occur near the foot of the inverted arch for the three kinds of lining. Thus, the test data basically coincide with the observed in situ data.展开更多
In this paper, cold simulation experiments and numerical calculations are conducted to predict 3 D flow field aerodynamics for an oil furnace after being retrofitted due to its fuel variation. K ε model and SIMPLE ...In this paper, cold simulation experiments and numerical calculations are conducted to predict 3 D flow field aerodynamics for an oil furnace after being retrofitted due to its fuel variation. K ε model and SIMPLE program under body fit coordination (BFC) system, in which TTM non orthogonal method is used to control the irregular geometric boundary, are adopted to solve the control equations. Model tests are conducted to check the calculation results, showing that they are in agreement with each other. Three different alternatives with different side window locations are also calculated to optimize the designs. The field retrofitting results show that the combination of cold tests with numerical calculations has prosperous application in retrofitting or renewing medium and small boilers.展开更多
为提高柴油机装配质量和冷试性能,基于柴油机装配冷试基础数据集,选取加州大学欧文分校(University of California Irvine,UCI)机器学习资料库标准数据集中的Seeds、Wine、Wdbc三种数据集,对比支持向量机(support vector machines,SVM)...为提高柴油机装配质量和冷试性能,基于柴油机装配冷试基础数据集,选取加州大学欧文分校(University of California Irvine,UCI)机器学习资料库标准数据集中的Seeds、Wine、Wdbc三种数据集,对比支持向量机(support vector machines,SVM)模型、组合智能算法改进后SVM模型、Transformer模型应用于冷试异常数据的分析效果。结果表明:SVM、改进后SVM,Transformer模型对正常数据和异常数据分类的准确率分别为85.20%、92.54%、97.94%;相比SVM、改进SVM模型,Transformer模型的分类准确率有较大的提高,可用于分析参数异常;排气压力与转矩关系密切,排气压力较大造成转矩增大;排气门开启时间过长导致进气真空度异常,验证了Transformer模型对发动机装配异常识别方法的有效性。展开更多
文摘Based on the similarity theory, taking the horseshoe, city-gate and round linings as examples, the value and distribution regularities of normal frost heaving pressures （hereinafter as frost heaving pressures） in tunnels excavated in fractured rock mass in cold regions under different constraints and freezing depths were studied by a test model. It was found that the larger the frozen depth, the larger the frost heaving pressure, and the stronger the top constraint, the larger the frost heaving pressure. For the horseshoe lining and city-gate lining, the top constraint has a greater effect on the frost heaving pressures on the arch and the inverted arch. For the round lining, the influences of the top constraint on the frost heaving pressure in all linings are almost the same. The frost heaving pressure is maximum on the city-gate lining and minimal on the round lining. The largest frost heaving pressure all occur near the foot of the inverted arch for the three kinds of lining. Thus, the test data basically coincide with the observed in situ data.
文摘In this paper, cold simulation experiments and numerical calculations are conducted to predict 3 D flow field aerodynamics for an oil furnace after being retrofitted due to its fuel variation. K ε model and SIMPLE program under body fit coordination (BFC) system, in which TTM non orthogonal method is used to control the irregular geometric boundary, are adopted to solve the control equations. Model tests are conducted to check the calculation results, showing that they are in agreement with each other. Three different alternatives with different side window locations are also calculated to optimize the designs. The field retrofitting results show that the combination of cold tests with numerical calculations has prosperous application in retrofitting or renewing medium and small boilers.
文摘为提高柴油机装配质量和冷试性能,基于柴油机装配冷试基础数据集,选取加州大学欧文分校(University of California Irvine,UCI)机器学习资料库标准数据集中的Seeds、Wine、Wdbc三种数据集,对比支持向量机(support vector machines,SVM)模型、组合智能算法改进后SVM模型、Transformer模型应用于冷试异常数据的分析效果。结果表明:SVM、改进后SVM,Transformer模型对正常数据和异常数据分类的准确率分别为85.20%、92.54%、97.94%;相比SVM、改进SVM模型,Transformer模型的分类准确率有较大的提高,可用于分析参数异常;排气压力与转矩关系密切,排气压力较大造成转矩增大;排气门开启时间过长导致进气真空度异常,验证了Transformer模型对发动机装配异常识别方法的有效性。
