7. Validation Test Case

7.1. Element based test cases

The ACCS RTM Solver has been validated using multiple test cases. Each test case features a 200mm model constructed with different element types, all sharing the same cross-section. Analytical one-dimensional infusion times are predicted using Darcy’s law for each model, and the solver’s results are then compared to these predictions.

7.1.1. Darcy’s Law Predicted Time

The theoretical infusion time is calculated using Darcy’s Law:

\[t = \frac{\eta \cdot L^2}{2 \cdot k \cdot P}\]

Where:

  • \(t\) = Predicted infusion time

  • \(v\) = Viscosity

  • \(L\) = Length

  • \(k\) = Permeability

  • \(P\) = Inlet pressure

7.1.2. Model Specifications

  • Inlet Pressure: \(0.8 \text{ MPa}\)

  • Length: \(200 \text{ mm}\)

  • Width: \(10 \text{ mm}\)

  • Height: \(2 \text{ mm}\)

  • Viscosity: \(1.3 \times 10^{-8} \text{ MPa} \cdot \text{s}\)

  • Permeability: \(4 \times 10^{-5} \text{ mm}^{2}\)

The predicted time for this model is \(8.125 \text{ s}\).

7.1.3. Simulation Results

Element Type

ACCS RTM Solver Predicted Time (s)

Linear Beam (1D)

8.125

Linear Triangle (2D)

8.12607

Linear Rectangle (2D)

8.12607

Linear Tetrahedron (3D)

8.11564

Linear Square Pyramid (3D)

N/A

Linear Triangular Prism (3D)

8.12123

Linear Hexahedron (3D)

8.125

Element Type

ACCS RTM Solver Predicted Time (s)

Quadratic Beam (1D)

8.125

Quadratic Triangle (2D)

8.12524

Quadratic Rectangle (2D)

8.125

Quadratic Tetrahedron (3D)

8.06668

Quadratic Square Pyramid (3D)

N/A

Quadratic Triangular Prism (3D)

8.125

Quadratic Hexahedron (3D)

8.17861

7.2. Flow Front Shape Test Cases

The following test cases demonstrate the behavior of flow fronts under different permeability conditions. The inlet is positioned in the middle, while the outlets are located on the outer edges.

7.2.1. Case 1: Circular Flow Front

In this scenario, the permeability in the x and y directions are equal (x = y). As a result, the flow front propagates in a circular shape.

_images/RTM_Circular_Model.png

Fig. 7.2.1 Circular Flow Front - Permeability x = y

7.2.2. Case 2: Elliptical Flow Front

In this scenario, the permeability in the x direction is twice that in the y direction (x = 2y). This leads to an elliptical flow front shape.

_images/RTM_Elipse_Model.png

Fig. 7.2.2 Elliptical Flow Front - Permeability x = 2y