排序方式: 共有6条查询结果,搜索用时 31 毫秒
1
1.
2.
A reduction of fuel consumption and an increase in efficiency are currently required for river–sea bulk carriers. Pre-swirl and ducted stators are widely used devices in the industry and efficiency gains can be obtained for single-screw and twin-screw vessels. Based on the hydrodynamic characteristics of the 20,000 DWT river–sea bulk carrier, in this study, we proposed,designed, and tested a series of pre-swirl energy-saving devices(ESDs). The experimental results demonstrate that the proposed ESDs improved the propulsive efficiency and reduced the delivered power. The results confirm the success of our ESD for the20,000 DWT river–sea bulk carrier. We validated the role of Reynolds-averaged Navier–Stokes(RANS) computational fluid dynamics(CFD) in the twin-skeg river–sea vessel ESD design and found the circumferential arrangement and number of stators to be important factors in the design process. 相似文献
3.
4.
5.
采用有限元软件,合理选用边界条件、加载方式、单元形状与类型、材料以及几何非线性等建立有限元模型,以试验结果[1]为基础,验证了模型的可靠性。参数化分析结果表明,被搭接支管受压时,其隐蔽部分是否焊接对节点承载力影响不大,被搭接支管受拉时,隐蔽部分是否焊接对节点承载力有较大影响。几何参数β(支管主管直径比)、γ(主管径厚比)对平面KT型圆钢管搭接节点承载力有显著影响,且β、γ两者对节点承载力也相互影响。γ较小时,τ对节点承载力有显著影响,γ较大时,τ对节点承载力影响不大。搭接率Ov对节点承载力影响不显著。利用多元线性回归分析技术,对有限元参数化分析结果进行回归分析,得到平面KT型圆钢管搭接节点承载力参数公式,最后,从适用性、安全性、连续性等方面验证了参数公式的可靠性。 相似文献
6.
为分析时间步长和无量纲壁面距离y+对实尺度船舶数值模拟结果的影响,以某23万载重吨散货船为例,以雷诺平均纳维-斯托克斯方程和连续方程为控制方程,采用有限体积法进行空间离散,通过控制时间步长和无量纲壁面距离y+的变化对该船开展实尺度阻力数值模拟研究。数值模拟结果表明,时间步长和y+对实尺度船舶数值模拟计算结果有很大影响,在一定范围内合理地设置这2个参数能提高实尺度船舶数值模拟的精度,研究成果可供同类型船舶的实尺度船舶快速性数值模拟参考。 相似文献
1