Development of Numerical Simulator of Ice-accretion on a Body in Oscillation

振动体积冰数值模拟器的研制

• 批准号: 12650059
• 负责人: TSUBOI Kazuhiro
• 金额: $ 2.18万
• 依托单位: Ibaraki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650059/
• 关键词: Ice-accretion problems; 2-fluid model; Incompressible flow; Body in oscillation; Computational Fluid Dynamics; Moving boundary problems; Stokes number; Particle density distribution; 着水問題; 淀み点流れ; 解析解; 着氷現象; 粒子流; 振動円柱; ポテンシャル流れ; 有限差分法

Numerical simulator has been developed based on Computational Fluid Dynamics appraoch, which is possible to predict the shape of accreted ice on a body surface in oscillation. In the present simulator, we employ Eulerian approach with 2-fluid description of multi-phase flow model in the basic codes, because this approach has the advantage in simulating flows around an oscillating body. The 2-fluid Saffman equation is used as a model of super-cooled atmosphere Then, we consider potential flow and viscous flow of Naver-Stokes solution as the carrier phase. The present simulator makes the following facts clear.(1) Prediction of local impingement efficiency along an oscillating cylinderBy solving the Saffman equation under the potential flow field of a circular cylinder with circulation in arbitrary translation, local impingement efficiency (distribution of mass flux) along the cylinder surface in pitching or heaving oscillation is obtained in some values of Stokes number. We also find uns … More teady behaviour of density field of water droplets around the cylinder by the visualization of computational results.(2) Prediction of the shape of accreted ice in viscous flowSimulation of hard-rime accretion on a circular cylinder is performed under the condition (Re=10^4, St=10) by coupling the Navier-Stokes equations. In Eulerian approach, there are two kinds of option for the process of hard-rime growth : one is choice of incoming velocity of droplet, the other is the direction of ice-growth. Computational results show each option gives the different shape of hard-rime. Since local impingement efficiency has the most important effect in the process of hard-rime growth, the present results suggest that Eulerian model has advantage of predicting wide variety of ice shapes rather than Lagrangian approach.(3) Density field of Saffman equationDensity field in the stagnation region is obtained analytically as the function of Stokes number based on potential flow model. This expression is a generalization of Michael's result in 1968. Less

基于计算流体动力学（CFD）方法建立了数值模拟器，可以预测物体表面积冰在振荡过程中的形状。在本模拟器中，我们采用欧拉方法与2-流体描述的多相流模型的基本代码，因为这种方法在模拟振荡体周围的流动具有优势。本文采用二流体Saffman方程作为过冷大气的模型，考虑Naver-Stokes解的势流和粘性流作为载体相。本模拟器清楚地说明了以下事实。(1)本文通过求解任意平移有环量圆柱势流场下的Saffman方程，得到了在一定Stokes数下，俯仰振荡或升沉振荡圆柱表面局部撞击效率（质量流量分布）。我们还发现 ...更多信息 通过计算结果的可视化，揭示了圆柱周围水滴密度场的稳定性。(2)粘性流中积冰形状的预测通过耦合Navier-Stokes方程，对Re=10^4，St=10条件下圆柱上的硬霜积冰进行了数值模拟。在欧拉法中，硬霜生长过程有两种选择：一种是液滴来流速度的选择，另一种是冰生长方向的选择。计算结果表明，每种方案给出了不同形状的硬霜。由于局部撞击效率在硬霜生长过程中起着重要的作用，因此欧拉模型比拉格朗日模型更适合于预测各种冰形。(3)Saffman方程的密度场基于势流模型，解析地获得了停滞区密度场与斯托克斯数的函数关系。这个表达式是Michael在1968年的结果的推广。少

项目成果

Tsuboi. K.: "Computational and Analytical Study on Particle Flow Field around A Circular Cylinder"15^<th>AIAA Computational Fluid Dynamics Conference. AIAA-2001-2650. 843-851 (2001)

坪井。

坪井一洋, 木村茂雄: "2流体方程式による円柱への着氷シミュレーション"第16回数値流体力学シンポジウム講演論文集. B12-5 (2002)

Kazuhiro Tsuboi、Shigeo Kimura：“使用二流体方程模拟气缸结冰”第 16 届计算流体动力学研讨会论文集 B12-5 (2002)。

Tsuboi,K.: "Computational and Analytical Study on Particle Flow Field around a Circular Cylinder "accepted in 15^<th> AIAA Computational Fluid Dynamics Conference at Anaheim, CA. AIAA paper 2001-2650. (2001)

Tsuboi,K.：“圆柱体周围粒子流场的计算和分析研究”在加利福尼亚州阿纳海姆举行的第 15 届 AIAA 计算流体动力学会议上被接受。

Tsuboi K. and Kimura, S.: "Computational Study on Local Impingement Efficiency of an Oscillating Circular Cylinder"AIAA paper 2000-2661. 1-14 (2000)

Tsuboi K. 和 Kimura, S.：“振荡圆柱体局部冲击效率的计算研究”AIAA 论文 2000-2661。

Tsuboi K, and Kimura, S.: "Particle Flow around an Oscillating Circular Cylinder based on Two-fluids Model"Computational Technologies for Fluid Thermal/Structural/Chemical Systems With Industrial Applications, ASME PVP. 424-1. 29-37 (2001)

Tsuboi K 和 Kimura, S.：“基于二流体模型的振荡圆柱体周围的颗粒流”工业应用流体热/结构/化学系统的计算技术，ASME PVP。