Numerical simulation of solidification process for biological colloids

Simulation Summary

This file contains the results of transient simulations for copper inserts positioned at angles of 0° and 15°. The latest version of Ansys Fluent 2023 R2 was used throughout the study. The finite volume mesh was generated using Ansys Fluent Meshing with the following configuration:

Mesh Generation Parameters:

• Local Sizing: No
• Surface Mesh:
• Use Custom Size Field: No
• Minimum Size: 0.01953125 mm
• Maximum Size: 0.5 mm
• Growth Rate: 1.2
• Size Functions: Curvature & Proximity
• Curvature Normal Angle: 18°
• Cells Per Gap: 1
• Scope Proximity To: Edges
• Draw Size Boxes: Yes
• Separate Out Boundary Zones by Angle: No
• Create Regions:
• Estimated Number of Fluid Regions: 2
• Add Boundary Layers:
• Enabled: Yes
• Offset Method Type: Smooth-transition
• Number of Layers: 3
• Transition Ratio: 0.272
• Growth Rate: 1.2
• Apply To: Fluid regions
• Grow On: Only walls
• Volume Mesh Generation:
• Solver: Fluent
• Fill With: Polyhedra
• Mesh Fluid Regions: Yes
• Mesh Solid Regions: Yes
• Sizing Method: Global
• Growth Rate: 1.2
• Max Cell Length: 0.6640875 mm
• Enable Parallel Meshing: Yes

Simulation Setup:

• Solver Settings:
• Type: Pressure-Based
• Velocity Formulation: Absolute
• Time: Transient
• Gravity: Enabled (Y = 9.81 m/s²)
• Models Enabled:
• Energy
• Solidification and Melting
• Viscous: Laminar

Materials Used:

From the Ansys material database:

• Water
• Copper (wire)
• Air

Custom material:

• Polystyrene
• Density: 1050 kg/m³
• Specific Heat Capacity (Cp): 1100 J/kg·K
• Thermal Conductivity: 0.12 W/m·K

Boundary Conditions:

• Air region temperatures:
• Variant 1: -22°C
• Variant 2: -80°C

Solution Methods:

• Gradient: Least Squares Cell Based
• Pressure: Second Order
• Momentum: Second Order Upwind
• Energy: Second Order Upwind
• Pseudo Time Method: Off
• Transient Formulation: Second Order Implicit
• Warped-Face Gradient Correction: Enabled

Initialization:

• Initial domain temperature: 22°C
• Copper insert temperature: -80°C
• Time step: 0.0001 s
• Number of time steps: Dependent on full solidification of fluid

Post-Processing and Output:

A cross-section was defined to monitor simulation results using two contours:

• Contour 1: Temperature
• Filled, Node Values, Boundary Values, Global Range
• Variable: Static Temperature
• Range: 76 K – 296 K
• Contour 2: Liquid Fraction
• Filled, Node Values, Global Range
• Variable: Solidification/Melting – Liquid Fraction
• Range: 0 – 1

Results were recorded as HSF animations every 100 time steps. Every 1000 frames from these animations were exported as JPEG images

File Structure and Content:

Simulation results are organized in folders corresponding to inclination angles and ambient temperature conditions:

Data catalog: 0_22_80

• Inclination angle: 0° (horizontal insert)
• Ambient temperature: –22 °C
• Initial insert temperature: –80 °C

Contents:

• liquid/ – sequence of images showing the phase change (solidification) of the insert over time
• temp/ – sequence of images showing the temperature distribution over time

Data catalog: 15_22_80

• Inclination angle: 15°
• Ambient temperature: –22 °C
• Initial insert temperature: –80 °C

Contents:

• liquid/ – solidification simulation frames
• temp/ – temperature evolution frames

Data catalog: 15_80 _80

• Inclination angle: 15°
• Ambient temperature: –80 °C
• Initial insert temperature: –80 °C

Contents:

• liquid/ – solidification simulation frames
• temp/ – temperature evolution frames