Application of L-R Two-Step Euler Method to Micro Ejection of Aluminum
-
摘要: 应用三维弹塑性流体力学Lagrangian-Remapping两步欧拉计算方法对铝材料微喷射现象进行了数值模拟研究。计算了Asay实验中表面刻有相同深度、不同夹角沟槽的金属铝微喷射模型,计算得到的微喷物总质量、最大射流速度和实验结果均符合较好。进一步展开了对相同深度、更大夹角范围沟槽微喷射的数值模拟。分析认为喷射最大速度随沟槽角度的增大呈线性下降趋势。同时给出了喷射系数随沟槽角度的变化的拟合关系曲线,看到由于材料强度及沟槽角度变化后造成的波系关系变化的影响,随着沟槽角度增加,喷射系数曲线呈明显非线性发展。Abstract: The 3D elastic-plastic hydrodynamic Lagrangian-Remapping two-step Euler method was used for the micro ejection simulation of aluminum.The micro ejection calculation models have grooves on the aluminum interface with the same depth and different angles, and the numerical results of the micro-jet mass and maximum velocity thus accorded with Asay's experiment results.And then, the micro ejection calculation models with the same groove depth but much larger angle range were calculated.By the analysis of the numerical results, it is showed that the maximum velocity of the micro-jet decreases linearly with the increase of the groove angle, and the curving contour of the ejected factor versus groove angle is given.Because of the influence of metal strength and groove angle on the wave relations, the micro-jet coefficient curve is obviously nonlinear with the groove angle.
-
Key words:
- Euler /
- L-R two-step method /
- micro-jet /
- ejected factor
-
表 1 6061-T6铝材料计算模型参数
Table 1. The simulation parameters of 6061-T6 aluminum samples
ρ0/(g/cm3) c0/(km/s) S1 S2 S3 γ0 α em Pmin/(GPa) G0/(GPa) Y0/(GPa) 2.7 5.376 1.55 0 0 2.19 1.7 0.88 0.45 27.6 0.276 表 2 Euler方法计算喷射量、最大速度和两组实验结果[2]对比
Table 2. Comparison between numerical and experimental results[2] of ejected mass and maximum velocity
Groove
angle/(°)Numerical results
of ejected mass
/(mg/cm2)Experimental results
of ejected mass
/(mg/cm2)Numerical results
of maximum velocity
/(km/s)Experimental results
of maximum velocity
/(km/s)15 1.63 1.46, 1.57 8.8 8.4, 8.6 30 1.60 1.58, 1.60 8.2 8.1, 8.3 45 2.32 2.07, 2.33 7.5 7.2, 7.5 60 2.35 - 7.1 - 75 2.62 - 6.7 - 90 2.92 2.60, 3.06 6.2 6.3 表 3 不同沟槽角度下的喷射系数和最大喷射速度
Table 3. The ejected factor and maximum velocity at different groove angles
Groove
angle/(°)Ejected
factorMaximum velocity
/(km/s)10 2.640 9.43 15 2.470 8.88 30 1.570 8.16 35 1.330 8.01 40 1.220 7.75 45 1.200 7.57 60 0.920 7.10 75 0.747 6.66 90 0.632 6.20 100 0.585 5.90 110 0.566 5.69 120 0.539 5.23 130 0.423 4.89 140 0.340 4.52 150 0.257 4.16 -
[1] Walsh J M, Shreffler R G, Willing F J. Limiting conditions for jet formation in high velocity collisions[J]. J Appl Phys, 1953, 24(3): 349-359. doi: 10.1063/1.1721278 [2] Asay J R. Material ejection from shock-loaded free surface of aluminum and lead, SAND 76-0542[R]. 1976. [3] Asay J R. A model for estimating the effects of surface roughness on mass ejection from shocked materials, SAND 78-1256[R]. 1978. [4] 陈军, 经福谦, 张景琳, 等.冲击作用下金属表面微喷射的分子动力学模拟[J].物理学报, 2002, 51(10): 2386-2391. http://www.cnki.com.cn/Article/CJFDTotal-WLXB200210040.htmChen J, Jing F Q, Zhang J L, et al. Molecular dynamics simulation of micro particle ejection from a shock-impacted metal surface[J]. Acta Phys Sin, 2002, 51(10): 2386-2391. (in Chinese) http://www.cnki.com.cn/Article/CJFDTotal-WLXB200210040.htm [5] 王裴, 秦承森, 张树道, 等. SPH方法对金属表面微射流的数值模拟[J].高压物理学报, 2005, 18(2): 149-156.Wang P, Qin C S, Zhang S D, et al. Simulated microjet from free surface of aluminum using smoothed particle hydrodynamics[J]. Chinese Journal of High Pressure Physics, 2005, 18(2): 149-156. (in Chinese) [6] 刘军, 何长江, 梁仙红.三维弹塑性流体力学自适应欧拉方法研究[J].高压物理学报, 2008, 22(1): 72-78. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=gywlxb200801016Liu J, He C J, Liang X H. An eulerian adaptive mesh refinement method for three dimensional eastic-plastic hydrodynamic simulations[J]. Chinese Journal of High Pressure Physics, 2008, 22(1): 72-78. (in Chinese) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=gywlxb200801016 [7] 何长江, 于志鲁, 冯其京.高速碰撞的三维欧拉数值模拟方法[J].爆炸与冲击, 1999, 19(3): 216-221. http://d.wanfangdata.com.cn/Periodical/bzycj199903005He C J, Yu Z L, Feng Q J. 3D eulerian numerical simulation method of high speed impact[J]. Explosion and Shock Waves, 1999, 19(3): 216-221. (in Chinese) http://d.wanfangdata.com.cn/Periodical/bzycj199903005 [8] 李德元, 徐国荣, 水鸿寿, 等.二维非定常流体力学数值方法[M].北京: 科学出版社, 1998.Li D Y, Xu G R, Shui H S, et al. Numerical simulation method of 2D-unsteady fluid flow[M]. Beijing: Science Press, 1998. (in Chinese) [9] Strang G. On the construction and comparison of difference schemes[J]. J Numer Anal, 1968, 5: 506-517. doi: 10.1137/0705041 [10] 石艺娜, 秦承森.金属射流失稳断裂的理论分析[J].力学学报, 2009, 41(3): 361-369. http://qikan.cqvip.com/Qikan/Article/Detail?id=30484364Shi Y N, Qin C S. Instability and breakup of stretching metallic jets[J]. Chinese Journal of Theoretical and Applied Mechanics, 2009, 41(3): 361-369. (in Chinese) http://qikan.cqvip.com/Qikan/Article/Detail?id=30484364 [11] 王继海.二维非定常流和激波[M].北京: 科学出版社, 1994.Wang J H. 2D-Unsteady Fluid Flow and Shockwave[M]. Beijing: Science Press, 1994. (in Chinese) [12] Walker J D. Incoherence of shaped charge jet[C]//14th International Symposium on Ballistics. Quebec, Canada, 1993: 165-172. [13] Walker J D. Incoherence of shaped charge jet[C]//16th International Symposium on Ballistics. San Francisco, 1996: 457-462.