Gasoline engines are increasingly popular for use in small unmanned aircraft requiring endurance due to the specific energy of gasoline (47.3 MJ·kg-1) and its cost effectiveness. However, gasoline is volatile and...Gasoline engines are increasingly popular for use in small unmanned aircraft requiring endurance due to the specific energy of gasoline (47.3 MJ·kg-1) and its cost effectiveness. However, gasoline is volatile and it poses a health hazard. In this work, isopropanol is proposed and investigated as viable fuel for small gasoline engines. Isooctane is used as a benchmark for performance comparison. The field testing reveals that isopropanol offers similar running performance and ease of starting. The maximum output power of isopropanol is surprisingly found to occur at a more advanced ignition timing compared with isooctane. The significant outcome of this study is that isopropanol can readily be used as a replacement fuel for existing engines without the need for any modifications to the ignition module or the engine itself.展开更多
将最小二乘支持向量机(Least square support vector machine,LS-SVM)应用于小样本民机产品的可靠性预测分析。通过重构相空间的饱和嵌入维数,确定最小二乘支持向量机的最佳输入变量;然后,使用最小二乘向量机建立可靠度回归预测模型,运...将最小二乘支持向量机(Least square support vector machine,LS-SVM)应用于小样本民机产品的可靠性预测分析。通过重构相空间的饱和嵌入维数,确定最小二乘支持向量机的最佳输入变量;然后,使用最小二乘向量机建立可靠度回归预测模型,运用自动网格搜索法,优化了最小二乘支持向量机的建模参数,实现了比现有方法精度高、泛化性好的模型。训练和测试的可靠性样本取自某机型襟翼液压锁寿命可靠性数据。与神经网络模型的比较实例表明,提出的方法合理有效。展开更多
文摘Gasoline engines are increasingly popular for use in small unmanned aircraft requiring endurance due to the specific energy of gasoline (47.3 MJ·kg-1) and its cost effectiveness. However, gasoline is volatile and it poses a health hazard. In this work, isopropanol is proposed and investigated as viable fuel for small gasoline engines. Isooctane is used as a benchmark for performance comparison. The field testing reveals that isopropanol offers similar running performance and ease of starting. The maximum output power of isopropanol is surprisingly found to occur at a more advanced ignition timing compared with isooctane. The significant outcome of this study is that isopropanol can readily be used as a replacement fuel for existing engines without the need for any modifications to the ignition module or the engine itself.
文摘将最小二乘支持向量机(Least square support vector machine,LS-SVM)应用于小样本民机产品的可靠性预测分析。通过重构相空间的饱和嵌入维数,确定最小二乘支持向量机的最佳输入变量;然后,使用最小二乘向量机建立可靠度回归预测模型,运用自动网格搜索法,优化了最小二乘支持向量机的建模参数,实现了比现有方法精度高、泛化性好的模型。训练和测试的可靠性样本取自某机型襟翼液压锁寿命可靠性数据。与神经网络模型的比较实例表明,提出的方法合理有效。
