To ensure the safety of America's 730 million annual air travelers, all new jet engines must undergo arduous FAA safety testing—including a grueling series of static ground tests subjecting them to everything from gale force winds to simulated bird strikes. But how does one reproduce the identical test conditions needed for accurate performance measurements? You use a 32-foot wide wind baffle, of course.
Technically, they're known as Turbulence Control Structures (TCS) and were patented in 1981 by a pair of Boeing engineers, Ulrich W. Ganz and Paul C. Topness. Originally developed to maintain a static load on the engines while performing noise level tests, each TCS is arranged in a "modified 9-frequency icosahedral frame" or "honeycomb" design.
When attached to an engine's intake the TCS's design aids in effectively smoothing and normalizing air flow through the engine. "You take wind-induced inlet airflow variation out of the picture," explains aerospace engineer Jose Gonsalez from GE Aviation. "You don't want that as a variable when you collect performance data across many days under different conditions." And by steadying the engine's work load over the course of the test while eliminating cross wind interference, engineers can extract better thrust and fuel consumption data as well.
Before the advent of the TCS, manufacturers and regulators alike had to wait for calm weather conditions—typically early morning or late afternoon—and tolerate large measurement variations. However, the TCS has garnered widespread adoption throughout the industry. The TCS pictured above, for example, resides at GE's Peebles Test Operation in Southern Ohio. It's built from 300 aluminum plates bonded to perforated steel sheets, measures more than 32 feet in diameter, and weighs about 30,000 pounds.
Here's what it looks like on the inside:
Here's what it looks like from below:
Here's what it looks like from really far away: