为了探究稀相纳米异质粒子对燃油射流喷雾特性的影响,基于纳米燃油喷雾可视化试验结果,应用计算流体力学软件建立含稀相纳米粒子的燃油喷雾模型,依据试验结果验证模型的准确性,并通过该模型研究喷油压力、环境温度和粒子质量浓度对CeO2...为了探究稀相纳米异质粒子对燃油射流喷雾特性的影响,基于纳米燃油喷雾可视化试验结果,应用计算流体力学软件建立含稀相纳米粒子的燃油喷雾模型,依据试验结果验证模型的准确性,并通过该模型研究喷油压力、环境温度和粒子质量浓度对CeO2纳米燃油的喷雾特性的影响。研究结果表明:在相同喷射压力下,不同喷雾发展时刻,纳米燃油的油束贯穿距和索特平均直径(Sauter mean diameter,SMD)比柴油的大,喷雾锥角比柴油的略小。随着喷射压力提高,纳米燃油与柴油在喷雾贯穿距、喷雾锥角和SMD上的差异增大,且差异与纳米粒子质量浓度呈正相关。当射流环境温度上升时,纳米燃油与柴油在喷雾贯穿距和SMD上的差异均有所增加,且在高温环境下,纳米燃油的贯穿距和SMD会逐渐比柴油的小,纳米粒子质量浓度越高,该现象越明显,而喷雾锥角的差距有所减小。展开更多
The paper concerns with generalized Riemann problem for isentropic flow with dissipation, and show that if the similarity solution to Riemann problem is composed of a backward centered rarefaction wave and a forward c...The paper concerns with generalized Riemann problem for isentropic flow with dissipation, and show that if the similarity solution to Riemann problem is composed of a backward centered rarefaction wave and a forward centered rarefaction wave, then generalized Riemann problem admits a unique global solution on t≥0. This solution is composed of backward centered wave and a forward centered wave with the origin as their center and then continuous for t 〉0.展开更多
文摘为了探究稀相纳米异质粒子对燃油射流喷雾特性的影响,基于纳米燃油喷雾可视化试验结果,应用计算流体力学软件建立含稀相纳米粒子的燃油喷雾模型,依据试验结果验证模型的准确性,并通过该模型研究喷油压力、环境温度和粒子质量浓度对CeO2纳米燃油的喷雾特性的影响。研究结果表明:在相同喷射压力下,不同喷雾发展时刻,纳米燃油的油束贯穿距和索特平均直径(Sauter mean diameter,SMD)比柴油的大,喷雾锥角比柴油的略小。随着喷射压力提高,纳米燃油与柴油在喷雾贯穿距、喷雾锥角和SMD上的差异增大,且差异与纳米粒子质量浓度呈正相关。当射流环境温度上升时,纳米燃油与柴油在喷雾贯穿距和SMD上的差异均有所增加,且在高温环境下,纳米燃油的贯穿距和SMD会逐渐比柴油的小,纳米粒子质量浓度越高,该现象越明显,而喷雾锥角的差距有所减小。
基金Supported by the NSF of Educational Department of Henan Province(200511051700)Supported by the NSF of Henan Province(200510078005)Supported by the NSF of China(10571024)
文摘The paper concerns with generalized Riemann problem for isentropic flow with dissipation, and show that if the similarity solution to Riemann problem is composed of a backward centered rarefaction wave and a forward centered rarefaction wave, then generalized Riemann problem admits a unique global solution on t≥0. This solution is composed of backward centered wave and a forward centered wave with the origin as their center and then continuous for t 〉0.
