混合罐:练习 5 - 分配边界条件
对于边界条件,流体行为和属性是在流体域的所有边界曲面上指定的。
指定边界条件
1. “边界条件”(Boundary Conditions)“普通边界”(General Boundaries) > “默认”(Default) 下,选择 FLUID_ROTOR
2. “模型”(Model) 选项卡中,为所列选项选择以下值:
“流动”(Flow) -“旋转壁”(Rotating Wall)
“旋转方向”(Rotational Direction) -“逆时针”(Counterclockwise)
“旋转速度”(Rotational Speed) - 12.57 弧度/秒
“旋转轴矢量”(Rotational Axis Vector) - 0,0,1
“旋转中心”(Rotational Center) - 0,0,0
指定体积块条件
1. “域”(Domains) 下,选择 FLUID_ROTOR
2. “模型”(Model) 选项卡中,为所列选项选择以下值:
“通用”(Common) >“体积块网格重划”(Volume Remesh) -“体积块网格重划”(Volume Remesh)
“方法”(Method) -“旋转”(Rotation)
“旋转方向”(Rotational Direction) -“逆时针”(Counterclockwise)
“旋转速度”(Rotational Speed) - 12.57 弧度/秒
“旋转轴矢量”(Rotational Axis Vector) - 0,0,1
“旋转中心”(Rotational Center) - 0,0,0
指定材料的体积块条件
1. 要设置流体,请单击 “材料”(Materials)“材料选择”(Material Selection) 对话框随即打开。选择新流体时,将自动设置流体的属性。
2. 为所有流体域选择水。
3. 在 Flow Analysis 树中选择 “域”(Domains)
4. “模型”(Model) 选项卡中,对于“流动”(Flow),为所列选项设置以下值:
“黏度”(Viscosity) -“恒定动态黏度”(Constant Dynamic Viscosity)
“值”(Value) - 0.001003 Pa-s
指定组分的初始条件
1. 在 Flow Analysis 树中,选择 “物理”(Physics) > “通用”(Common)
2. “操作”(Operations) 组中,单击 “表达式编辑器”(Expression Editor)
3. “表达式编辑器”(Expression Editor) 对话框中,输入以下内容:
# Species initial condition
species_initial_level= (z>1.00) ? 1 : 0
##############################################################################
# Output Volume Weighted Uniformity Index #
# ------------------------------------------------------------------------ #
# In this example, the volume weighted uniformity index for concentration of "1" on whole volume were calculated and added as XY-plot variable #
# The variable is plotted by selecting "Common" in the Flow Analysis tree. #
##############################################################################
# interested variable
phi = species.01.C
# Volume Weighted Uniformity Index
# ==============================
# step 0: calculate total volume
# ------------------------------------
#vol_t = integral(1, volume.FLUID_ROTOR_Body_1)+integral(1, volume.FLUID_STATOR_Body_1)
vol_t = 1.08811
# step 1: calculate volume averaged phi for all volumes
# --------------------------------------------------
phi_t = integral(phi, volume.FLUID_ROTOR_Body_1)+integral(phi, volume.FLUID_STATOR_Body_1)
phi_a = phi_t/vol_t
# step 2: calculate volume weighted uniformity index
# ------------------------------------------------
phi_awui = 1 - 0.5*( integral(abs(phi-phi_a), volume.FLUID_ROTOR)+
integral(abs(phi-phi_a), volume.FLUID_STATOR_Body_1) )/ phi_a /vol_t
# step 3: add plot variable
# -------------------------
plot.phi_awui = phi_awui
#plot.phi_awui: Volume Weighted Uniformity Index Species 1 [-]
4. 单击“确定”(OK)
5. 在 Flow Analysis 树中选择 “域”(Domains)
6. “模型”(Model) 选项卡中,单击 Species 01
7. 针对“初始条件”(Initial Condition),将“值”(Value) 设置为 species_initial_level
均匀性指数
通常情况下,搅拌性能可通过目视均匀性以及局部浓度随时间和平均浓度的量变进行评估。Creo Flow Anaysis 中的 “表达式编辑器”(Expression Editor) 可用于评估体积加权均匀性指数组分和体积平均组分的数量变化。
体积平均 phi 和加权均匀性指数可通过以下方程进行计算:
volume averaged phi: phi_a = Sum(phi)/volume
volume weighted uniformity index: u_i = sum(abs(phi-phi_a))/volume/phi_a
这对您有帮助吗?