当前位置: X-MOL 学术Exp. Therm. Fluid Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Surface conductivity effects during shock wave reflection off curved surfaces
Experimental Thermal and Fluid Science ( IF 2.8 ) Pub Date : 2021-02-06 , DOI: 10.1016/j.expthermflusci.2021.110353
A. Cohen , B.W. Skews

Previous work has shown that heat transfer into a plane conducting surface affects shock wave reflection properties. In the more complex reflection case of a curved surface the situation would be different because of the increased number of reflection patterns, with a rapid change in reflection geometry as the wave propagates up the surface. Test pieces of different thermal conductivities (0.19 W/mK and 401 W/mK) and hydraulically smooth surfaces are used on both convex and concave cylindrical surfaces. The test pieces are placed in identical positions on either side of a plane of symmetry and at the same incident angles in a shock tube. Tests are performed at incident shock Mach numbers of 1.22< M <1.5 and imaged using high-speed shadowgraph photography. The images are analyzed both quantitatively through reflection angle measurements and qualitatively by searching for asymmetry. Both the qualitative and quantitative measurements clearly indicate that the thermal conductivity of the surface affects the reflection patterns due to the complex transient thermal environment. Asymmetry in the reflection patterns is found at all Mach numbers. In contrast to the plane wall case the lack of theory limits comparison, where in that case it was shown that the lower the thermal conductivity the closer the experimental results approached the ideal adiabatic case. Similar comparisons in the relationship of reflection types between different materials are found in the current case. The findings could be refined by using higher imaging frame rates and spatial resolution, and sophisticated numerical modeling.



中文翻译:

冲击波从曲面反射时的表面电导率效应

先前的工作表明,热量传递到平面传导表面会影响冲击波的反射特性。在曲面更复杂的反射情况下,情况会有所不同,因为反射图案的数量增加了,并且随着波在表面上的传播,反射几何形状也发生了快速变化。在凸圆柱面和凹圆柱面上均使用不同导热率(0.19 W / mK和401 W / mK)和液压光滑表面的试件。将试件放置在对称平面两侧的相同位置,并在冲击管中以相同的入射角放置。测试是在入射冲击马赫数为1个22< 中号 <1个5并使用高速阴影照片摄影进行成像。通过反射角测量对图像进行定量分析,并通过搜索不对称性对图像进行定性分析。定性和定量测量都清楚地表明,由于复杂的瞬态热环境,表面的热导率会影响反射模式。在所有马赫数下都发现反射图案不对称。与平面壁情况相比,缺乏理论限制了比较,在这种情况下,表明导热系数越低,实验结果越接近理想的绝热情况。在当前情况下,在不同材料之间的反射类型关系中也有类似的比较。

更新日期:2021-02-09
down
wechat
bug