To ensure the safety of the 730 million people travelling by air through the US each year, all new jet engines must undergo arduous FAA safety testing. But how does one reproduce the identical test conditions needed for accurate performance measurements? You use a 10m 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 normalising 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 aluminium plates bonded to perforated steel sheets, measures more than 10m in diameter, and weighs about 14,000kg.
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:
Pictures: General Electric