Aerodynamic Design Optimization Harvey Thompson & Colleagues

1. School of Mechanical Engineering FACULTY OF ENGINEERING Aerodynamic Design OptimizationHarvey Thompson& Colleagues

2. School of Mechanical Engineering FACULTY OF ENGINEERING Importance of Aerodynamic Drag- Computational Fluid Dynamics (CFD)- Aerodynamic Design Optimization via CFD

3. School of Mechanical Engineering FACULTY OF ENGINEERING Importance of Aerodynamic DragAerodynamics is a crucial component of a vehicle’s energy efficiencyE.g. ETSU (2001) Truck Aerodynamic Styling: over 1/3 of Heavy Goods Vehicles’ Fuel Burn related to aerodynamic drag

4. School of Mechanical Engineering FACULTY OF ENGINEERING Computational Fluid Dynamics (CFD)CFD – solving governing equations of heat and fluid flow on computers. Can provide ability to carry out ‘virtual experiments’.CFD increasingly important in vehicle design: E.g. US Department of Energy funded consortium (>$5 million) - best practice guidelines for CFD in truck design.

5. School of Mechanical Engineering FACULTY OF ENGINEERING Computational Fluid Dynamics (CFD)E.g. Flow pastsmall livestock trailer (Ifor Williams) Wake wake Recirculation recirculation

6. School of Mechanical Engineering FACULTY OF ENGINEERING Computational Fluid Dynamics (CFD)Flow is highly turbulent – hence need to validate turbulence model predictions: flow in wake particularly challenging e.g. wind tunnel testing

7. School of Mechanical Engineering FACULTY OF ENGINEERING Aerodynamic Design Optimization via CFDValidated CFDmodels can be used to investigate benefits of design changes. E.g. effect of inlet on ventilation rate for animals.

8. School of Mechanical Engineering FACULTY OF ENGINEERING Aerodynamic Design Optimization via CFDMore efficient to combine CFD with formal methods for multi-objective optimization. E.g. effect of headboard fairing on drag/ventilation Three possible Three resultant fairingsdesign parameters

9. School of Mechanical Engineering FACULTY OF ENGINEERING Aerodynamic Design Optimization via CFDUse ‘Design of Experiments’ to minimize number of CFD calculations needed to generate a ‘response surface’ Small D1 Large D1

10. School of Mechanical Engineering FACULTY OF ENGINEERING Aerodynamic Design Optimization via CFDUse response surface to identify ‘best’ design subject to your multi-objective criteria.E.g. Identify minimum dragwith acceptable ventilation rate for animals. Small D1 Large D1

11. School of Mechanical Engineering FACULTY OF ENGINEERING Aerodynamic Design Optimization via CFDAutomatic parametrisation and optimization of aero engine compressor blade: ≈ 1% increase in adiabatic efficiency. Small D1 Large D1