1. School of something FACULTY OF OTHER School of Mechanical Engineering Energy Efficient Vehicles for the Future Topology Optimization in Vehicle Design James Eves Institute of Engineering Thermofluids, Surfaces & Interfaces (iETSI) Multidisciplinary Optimization Group at the University of Leeds (MOGUL) Energy Efficient Vehicles of the Future School of Mechanical Engineering, University of Leeds 29 th April 2009

2. School of Mechanical Engineering Energy Efficient Vehicles for the Future Topology Optimization Optimization approach that differs significantly from conventional ones Used to determine the optimal distribution of material within a design space Density of each element in the designable space is a design variable Create designable space Apply load case Formulate problem Min. compliance Volume fraction < 0.3

3. School of Mechanical Engineering Energy Efficient Vehicles for the Future Shape Optimization – Topology Optimization Why Topology Optimization? Conventional shape optimization requires a good first design point. Results in designs that are based on ‘what has been done before.’ Topology optimization allows design concepts that may not be intuitive. Topology optimization is a valuable tool for generating conceptual designs. Traditional shape and size optimizations are still important later in the design process.

4. School of Mechanical Engineering Energy Efficient Vehicles for the Future APPLICATIONS OF OPTISTRUCT OPTIMIZATION TO BODY IN WHITE DESIGN Carl Reed – Jaguar Cars Ltd. Optimization of structural performance without increasing mass

5. School of Mechanical Engineering Energy Efficient Vehicles for the Future APPLICATION OF TOPOLOGY, SIZING AND SHAPE OPTIMIZATION METHODS TO OPTIMAL DESIGN OF AIRCRAFT COMPONENTS Lars Krog, Alastair Tucker and Gerrit Rollema – Airbus UK Ltd. Optimization of aircraft wing ribs to reduce mass and improve compliance

6. School of Mechanical Engineering Energy Efficient Vehicles for the Future Re=1 Re=100 Re=10 Topology Optimization of Flow Domains Very computationally expensive but attracting increasing attention Porosity of elements used as design variables rather than density Minimizing drag of an object in an external flow Topology optimization of flow domains using the lattice Boltzmann method Georg Pingen · Anton Evgrafov · Kurt Maute – Center for Aerospace Structure, University of Colorado

7. School of Mechanical Engineering Energy Efficient Vehicles for the Future Blended Wing Body Aircraft Wings and body ‘blended’ together into a single lifting surface. Advantages Increased aerodynamic efficiency Increased payload Reduced noise impact NASA X-48A (top) and Boeing X-48B (bottom)

8. School of Mechanical Engineering Energy Efficient Vehicles for the Future Topology optimization used to determine optimal position of spars in a conceptual BWB UAV design supplied by QinetiQ Ltd. Minimal compliance formulation Constraints on mass, wing tip displacement and wing twist Limitations of topology optimization Certain constraints difficult to implement: Local deformation of wing skin Structural stability

9. School of Mechanical Engineering Energy Efficient Vehicles for the Future Shape Optimization Average rib spacing of 2 feet used as initial design point Rib positions and orientations optimized to maximize buckling load factor Topology Optimization Introduction of additional load cases allows local and global deformation of the wing to be considered. Distributed material works with non- designable ribs to improve stiffness.

10. School of Mechanical Engineering Energy Efficient Vehicles for the Future Interpretation as Spars & Ribs Results from shape and topology optimization used to build a FEM of the aircrafts structural layout Size Optimization Thicknesses of spars, ribs and wing skin optimized to minimize mass Optimization procedure gives 10% mass reduction, contributing to increased efficiency

11. Any Questions? School of Mechanical Engineering Energy Efficient Vehicles for the Future