The future of propulsion will at least be complemented heavily by adaptive engine design, according to a panel of experts and industry executives. And Chief of Staff Gen. David Goldfein thinks that future is bright. “I believe we’ll bring propulsion in aircraft … forward in a way no one else can,” he said Thursday at AWS17. Speaking in a different panel at the same event, executives from General Electric, Pratt & Whitney, Rolls-Royce, and a subject expert rolled around ideas and concepts about the future of engines. Mark Lewis, director of the Institute for Defense Analyses’ Science and Technology Policy Institute, said development of propulsion will focus on better cycle efficiency (like an adaptive engine or alternative energy sources, for example), better propulsive efficiency (such as higher bypass/unducted fans), and better components (improved blades, for example). However, Lewis emphasized that rockets are currently very efficient, clocking it at rates higher than 90 percent, which is better than gas turbines (65 percent), cars (20 percent), and human beings (15 percent).
Pratt & Whitney is going to be testing modifications to its F-135 engines in the Spring, said James Kenyon, the company’s director of advanced programs and technology. He added that additive manufacturing came in very useful as Pratt played with capabilities for these modifications, allowing engineers to “try things” they couldn’t have tried otherwise. More specifically, Phil Burkholder, Rolls-Royce’s president of Defense Aerospace in North America, said the company would be focusing on developing technologies in tilt-rotor aircraft, unmanned tilt-rotor aircraft, distributed propulsion, and hybrid engine designs. General Electric’s Dan McCormick, the company’s general manager for the advanced combat engine, said the company’s three-stream architecture—an advanced method of air injection as opposed to what a turbojet or turbofan offers—is one way to achieve the type of adaptive engine efficiency that will revolutionize engine tech in the future. Regardless of the future of engines, the old battle between efficiency and energy will be at the center of innovation.