Applications of Microfluidics in Renewable Energy
- 1. Drag Reduction using Micro-channels Prepared by: Ahmed Maher Yehia Hazem M. El-Bolqeeny Tarek M. El-Gendy
- 2. 1. Introduction 2. Validation 3. Case Study 4. Fabrication Contents
- 3. 1.1 Why Drag Reduction? 1.2 Drag Reduction Techniques 1.2.1 Why Passive Technique? 1.3 Literature Review 1.4 What we are up to 1. Introduction
- 4. • Fuel Consumption - Cost - Environmental Impact - Non-renewable • Growing Energy Demand - Enhancing Renewable Energy 1.1 Why Drag Reduction?
- 5. 1.1 Why Drag Reduction?
- 6. 1.2 Drag Reduction Techniques Altering Fluid Flow Energy Input - Ex: Flow and Wall Oscillations Geometrical Modifications No Energy Input - Ex: Riblets (Our Point of interest) Active Technique Passive Technique
- 7. • Simple • Easy to fabricate and simulate • Reasonable Efficiency (5:18%) • No Feedback Control is needed 1.2.1 Why Passive Technique?
- 8. Outstanding work 1.3 Literature Review Kline et al. 1967 Walsh 1983 Bechert et al. 1997 Lee & Lee 2001
- 9. 1.3 Literature Review Bechert et al. 1997 & 2000 Lee & Lee 2001
- 10. 1.4 What we are up to Wind Turbine Blade Conditions and Riblets Geometry Effectiveness Validation
- 11. 2.1 Case Description 2.2 Analytical Solution 2.3 Numerical Solution 2.4 Results 2. Validation
- 12. Smooth Flat Plate - Characteristic Length = 1 m - Fluid: Air with Density = 1.225 kg/m3 - Viscosity = 1.8 * 10-5 kg/m.s - Free Stream Velocity = 30 m/s - No Slip Condition Wall 2.1 Case Description
- 13. For a smooth flat plate: Total Drag Coeff. = Skin Drag Coeff. 𝐶𝑓 = 1 𝐿 0 𝐿 𝐶𝑓,𝑥 𝑑𝑥 𝐶𝑓,𝑥 = 0.059 𝑅𝑒 𝑥 1 5 Hence, Cf = 4.05 * 10-3 2.2 Analytical Solution The Target Value
- 14. Calculating The Boundary Layer Thickness: δ ~ 0.02 m • Inlet Height = 5δ = 0.1 m 2.3 Numerical Solution
- 15. Mesh Generation • The Lower Face (L*V2) • The Upper Face (L*V1) 2.3 Numerical Solution
- 16. 2.3 Numerical Soultion Identifying The First Layer Thickness The Desired y+ Value k-ε Realizable with Enhanced Wall Treatment (Why?)
- 17. 2.4 Results Cf from FLUENT = 4.09 * 10-3 Relative Error ~ 0.99%
- 18. 3.1 Our Case State 3.2 Dimensions & Boundary Conditions 3.3 Case Assumptions 3.4 Results 3. Case Study
- 19. The Airfoil DU 96-W-180 Re = 2.2*106 Conditions at 40% of Chord Length (C = 1 m) δ ~ 0.009 m U∞ = 32 m/s 3.1 Our Case State
- 20. 3.2 Dimensions & B.C. Domain 1 cm * 1 cm A. Inlet • Velocity Inlet • Height = 1 cm B,C. Outlets • Pressure Outlets • Length = 1 cm (each) D. Wall • 8 Grooves, Square 100*100 μm (Why?), 200 μm apart • No Slip Condition
- 21. 2D Problem (How?) Steady State (How?) Pressure Based Model Adiabatic Flow Continuum Flow Newtonian Fluid 3.3 Case Assumptions
- 22. 3.4 Results Plate with Micro-Channels Smooth Plate
- 23. 3.4 Results Plate with Micro-Channels Smooth plate
- 24. Smooth PlatePlate with Micro-Channels 0.000137004560.00012741518Viscous drag coeff. 05.0308696 * 10-6Pressure drag coeff. 0.000137004560.00013244605Total drag coeff. 3.4 Results Benefits 7.53% Skin Friction Reduction 3.44% Total Drag Reduction
- 25. Soft Lithography PDMS • Making Up • Degasification Spin Coater Curing 4. Fabrication
- 26. 4. Fabrication Our Simplified Prototype
- 27. 4. Fabrication Vacuum Oven Spin Coater
- 28. Thank You For Your Attention Any Questions?