444- (CFD & FEA)

You are required to complete the Computational Methods coursework (CFD & FEA) using ANSYS and produce a professional technical report. All work must be carried out individually.

—

## 1. Student Information

Student ID: 202421340

From this ID:

– A = 10 (since last digit = 0 use 10)

– B = 4

– E = 40 GPa

– P = 10 GPa (since last digit = 0 use 10)

—

## 2. CFD Assignment

### Task 1: Flow Through a Bifurcated Tube

You are required to analyse water flow through a Y-shaped tube using CFD.

#### Geometry:

– Inlet diameter = 2A = 20 cm

– Outlet diameters = A = 10 cm each

– Element size = 0.00BA = 0.00410 m

#### Requirements:

1. Build the geometry in ANSYS.

2. Generate a high-quality mesh (include inflation layers near walls).

3. Apply boundary conditions:

– Velocity inlet

– Pressure outlets (0 Pa gauge)

4. Perform two simulations:

– Laminar flow

– Turbulent flow (Re > 4000)

#### Analysis:

– Calculate Reynolds number.

– Compare CFD results with theoretical values:

– Continuity equation

– DarcyWeisbach equation

– Use turbulence models:

– k- model

– k- SST model (for comparison)

– Clearly state turbulence model assumptions.

#### Outputs:

– Velocity contours

– Pressure contours

– Velocity profile (laminar vs theoretical parabola)

– Quantitative comparison (percentage error)

—

### Task 2: Laminar Flow in a Nozzle

#### Given:

– Inlet height = 0.2 m

– Area reduction = 20%

#### Requirements:

1. Model the sinusoidal nozzle in ANSYS.

2. Apply laminar flow conditions.

3. Perform mesh independence study:

– Coarse, medium, fine meshes

4. Validate results using theory:

– Parabolic velocity profile

– Entrance length

– Pressure drop

#### Outputs:

– Velocity distribution

– Pressure distribution

– Mesh comparison table

– Convergence justification (< 2% variation)

—

## 3. FEA Assignment

### Task 1: Tunnel Under External Pressure

#### Material Properties:

– Youngs Modulus = 40 GPa

– Poissons Ratio = 0.15

#### Loading:

– External pressure = 10 GPa

(Note: This value is unrealistically high and is used only for academic purposes based on Student ID.)

#### Boundary Conditions:

– Fixed support at the bottom

#### Requirements:

1. Model the tunnel geometry in ANSYS.

2. Apply pressure on top and side surfaces.

3. Perform structural analysis (plane strain).

#### Outputs:

– Maximum deformation

– Maximum von Mises stress

– Stress distribution plots

– Explanation of stress concentration locations

—

### Task 2: Truss Bridge Analysis

#### Material:

– Youngs Modulus = 40 GPa

– Poissons Ratio = 0.29

#### Cross Section:

– A B = 10 mm 4 mm = 40 mm

#### Loading:

– Three point loads = 30 kN each

#### Boundary Conditions:

– Left: pinned support

– Right: roller support

#### Requirements:

1. Model the truss using LINK180 elements.

2. Apply loads and supports.

3. Perform structural analysis.

4. Validate results analytically (method of joints).

#### Outputs:

– Joint deflections

– Deformation plot

– Stress distribution

– Percentage error vs analytical results

—

## 4. Simulation Settings (Important)

– Solver: Pressure-based solver (Fluent)

– Discretization: Second-order upwind

– Pressure-velocity coupling: SIMPLE

– Convergence criteria:

– Residuals < 110 (laminar)

– Residuals < 110 (turbulent)

– Mass imbalance < 0.1%

—

## 5. Mesh Requirements

– Use multiple mesh sizes for validation

– Ensure:

– Skewness < 0.85

– Orthogonal quality > 0.15

– Include mesh images in report

– Demonstrate mesh independence

—

## 6. Report Requirements

Prepare a professional report (maximum 8 pages) including:

### Sections:

1. Abstract

2. Introduction

3. Theory and Methodology

4. Results and Discussion

5. Conclusion

6. References

—

### Important Notes:

– Include ANSYS figures (contours, mesh, deformation)

– Clearly label all figures and tables

– Compare CFD/FEA results with theory

– Include percentage error

– Discuss limitations (e.g., steady-state assumption, linear elasticity)

– Use clear academic English

—

## 7. Submission Details

– Format: WORD

– Maximum length: 8 pages

– Submission via Moodle

– Deadline: As specified by the module

—

Ensure all results are accurate, validated, and clearly explained. The work should demonstrate strong understanding of CFD and FEA principles and correct use of ANSYS tools.