How to improve a civil aircraft’s aerodynamics? What design will reduce fuel consumption? How can the aircraft be made more spacious and comfortable for passengers?

To study the efficiency of alternative long-haul aircraft designs is the main goal of the Integral-MC Research coordinated by the NRC “Zhukovsky Institute”.

To that end, TsAGI (a part of NRC “Zhukovsky Institute”) is comparing different aircraft designs aimed to deliver 220–250 passengers for 8-9 thousand km.

TsAGI is studying various advanced long-haul aircraft designs, from classical to integral where fuselage is smoothly blended with the wing. Three likely options for the future airliner are being considered.

MC-1 is the first option with the classical circular fuselage. MC2 and MC3 are the other options which have oval fuselage and differ by location of wing. The third design is distinguished by a wingbox/fuselage strake which allows for better aerodynamics and low-speed lift performance thus reducing the required runway length. Oval fuselage should reduce fuel consumption and increase passenger space, thereby increasing flight comfort. The aircraft will also have a wider lower deck which should store more cargo. Unlike classical timeproven designs, however, these alternative designs have been insufficiently studied and require detailed long-term research.

TsAGI designed, developed and manufactured a unique combined aerodynamic model that can be used for testing these three configurations of the advanced long-haul aircraft.

‘Preliminary activities shaped the aerodynamic design of the advanced mainline aircraft giving higher performance than the current solutions. Indeed, this is relevant for domestic air travel availability,’ said Aleksandr Krutov, Researcher, Center for Complex Integration of Technologies, TsAGI.

Then, TsAGI did a low-speed wind tunnel tests of the combined model, with the velocity of 50 m/s at the attack and sideslip angles. The tests revealed the aerodynamic performance of all three designs, including efficiency of the elevator and rudder, as well as the interference of the units—the empennage and nacelles. The comparison showed no fundamental differences in the MC3 from classical designs at low velocities; moreover, it has better lift and moment performance.

At the next stage, TsAGI will do transonic cruise wind tunnel tests of the combined model.