Aerion is here in Dubai to tap what it believes could be strong market for the supersonic business jet (SSBJ) it intends to have certified in 2015. According to the U.S. company, it still holds letters of intent for about 50 of the aircraft and has had to refund only two deposits since the start of the financial crisis. Meanwhile, it is continuing its protracted talks to find a manufacturing partner for the program at a time when airframers are understandably cautious about extending their risk in new ventures.
The Aerion design consists of an airframe with a straight wing featuring “natural laminar flow (NLF)” aerodynamically optimized for transonic and supersonic flight up to speeds of Mach 1.6, with boomless flight at Mach 1.1. The company has scheduled flight tests of a larger NLF wing section aboard a NASA F-15B Eagle Strike Fighter to define manufacturing tolerances for optimum laminar flow over a supersonic airfoil. The first of these flights should be achieved before the end of this month.
With the ability to carry a larger wing test section aloft, Aerion (Stand E548) said it can investigate the effects of various surface imperfections. The wing on the full-scale Aerion will be thin, tapering from about nine inches in thickness at the root to three inches at the tip. Manufacturing tolerances will have to be carefully defined to ensure laminar flow, which is what these tests will help determine. The new wing section will investigate higher Reynolds number conditions, closer to the actual flight conditions of a full-scale wing at altitude.
According to Aerion, the risk associated with its program is reduced because of a strategy of combining systems and materials that are conventional, reliable and commonly in use in current production design, as well as conventional materials and manufacturing techniques. It said its SSBJ will not contain “exotic structural materials or manufacturing techniques” and that systems will represent best current practices and be similar to those now used for large business jets. The selected powerplant is the Pratt & Whitney JT8D-219, which is in widespread use on subsonic aircraft.
Meanwhile, to establish surface quality requirements Aerion and NASA have tentative plans to test transonic and supersonic laminar-flow wing performance at NASA’s Ames Research Center wind tunnel complex in Sunnyvale, California. Aerion had planned to test a selection of 7-percent-scale exhaust nozzles in a United Technologies noise-measurement wind tunnel last month and, concurrently, engine inlet designs but it remains unclear when this stage of development will be reached. The SSBJ pioneer previously modeled numerous nozzle configurations in computer simulations and tested them as small-scale models in an anechoic chamber at the University of California at Irvine.