Research Experience for Undergraduates: Jet Engine Design and Optimization This project consists of the design and optimization of jet engines. Optimization will be done both on components and eventually, engine cycle.

Research Experience for Undergraduates: Jet Engine Design and Optimization Cut-away of a PW4156 courtesy of /www.epower-propulsion.com Supporting Disks Beginning with the high pressure compressor, the conflicting objectives of weight and efficiency will be explored. In the compressor, there are many heavy rotating disks which support the blades attached to them. By reducing the number of blades, the required weight of the disk will be reduced, but the efficiency will suffer.

Evolutionary Optimization The main optimization technique to be used is an Evolutionary Algorithm which works like natural selection to find a group of optimum solutions to the problem at hand. Basic steps: Create an initial random population Select a number of points based on fitness (natural selection) Apply recombination and mutation to generate new solutions from selected survivors Evaluate new design points Replace members and create new population Go to step 2 Chose evolutionary algorithm for its robustness and ability to deal with discontinuous design space and local minima. Selection of points is analogous to natural selection, where poor combinations do not survive. After recombination, mutation is applied. This is in a random direction in the design space, with random magnitude. After evaluation of new points, those that are better than their predecessors are re-inserted into the population. Mutation

Pareto of Mass and Adiabatic Efficiency The optimization process yields results like this chart. The opposing goals of high efficiency and low mass produce not a single optimized solution, but a group of solutions called a Pareto front. This allows for the tradeoffs to be seen. EEE Blade Counts, 85.62% Pareto Choice, 85.76% Crude estimate: 0.1% HPC efficiency is about 37 kg fuel for a 4 hour mission 1 Kg compressor mass is about 3kg aircraft mass