Russia's Central Aerohydrodynamics Institute (TsAGI) has carried out a study into a future small business jet-type aircraft with "enhanced levels of comfort" at high subsonic speeds thanks to a specially-formulated fuselage shape designed to reduce drag.

The windtunnel research, which the agency says was at its "own instigation and not for a commercial client," tested a model of an aircraft representative of a jet weighing around 6,000kg, capable of carrying six passengers 1,730nm (3,200km) or three passengers 2,270nm.

The aircraft model was tested at cruising speeds and also at high Reynolds numbers - signifying turbulent or unstable airflow - and low airspeeds, TsAGI says.

TsAGI biz jet wind tunnel testing


The model's main feature is that it used an area-ruled shape to help enhance comfort, TsAGI says. A straight wing would normally limit an aircraft to a speed of Mach 0.7-0.72. However, the institute's research showed its new design could reach speeds of up to M0.77 while flying to maximum range, and reach a maximum cruising speed of M0.8.

"The capabilities of subsonic wing aerodynamics from the point of view of profiling are practically at their limits today," TsAGI's head of research for rocket and aircraft aerodynamics Ivan Chernyshev says.

"Further potential exists in the use of the aerodynamic interface between elements of the aircraft. A more or less well-known example of this interface is the area-rule for near-supersonic aircraft. Something like this has been used in our aircraft, and we've been granted a patent for it," he adds.

No manufacturer has so far committed to the project, but Chernyshev remains hopeful that its work will be continued by one of Russia's design bureaux.

The area-rule is a design technique with the aim of reducing drag at transonic and supersonic speeds, typically M0.75-1.2.

An area-ruled design prevents formation of shock waves and their associated wave drag, by making changes in the cross-section shape as smooth as possible.

Russia has not produced a modern business jet, although Sukhoi has considered building a supersonic type in recent years in partnership with Alenia, a project that its website says is still ongoing.

Source: Flight International