Interview of the Deputy Director General of TsAGI, Head of the Aircraft Aerodynamics and Flight Dynamics Complex, Sergei Lyapunov by TsAGI News Magazine.
Sergey Vladimirovich, how would you generally describe the past year?
I think that our personnel met the New Year 2014 with a sense of accomplishment. A large number of interesting projects has been completed in the past year, planned objectives have been achieved. Departments of the Complex are increasingly working in conjunction with each other, a series of cross works is being performed, and it’s very positive.
Please tell us about participation of Complex experts in contracts of the Federal Target Program (FTP) “Development of Russian civil aviation” in the past year.
The Aircraft Aerodynamics and Flight Dynamics Complex is the executive coordinator of the three largest FTP research (R&D) projects. The first one is “Progress-Aero,” which includes a variety of topics. One focus of the project is exploratory research of new aircraft assembly solutions, not only from the standpoint of high aerodynamic efficiency. In our time, acoustic problems are becoming increasingly important. One of the major issues in this regard is noise control. The engine as the main source of noise can be shielded by some elements of the aircraft.
Today the interest of experts around the world is attracted by aircraft design with engines mounted in an unconventional way, for example, over the wing or on the fuselage. Our research showed that engine relocation, unfortunately, adversely impacts aerodynamics. Our task is to weigh the pros that we get in the field of acoustics, with the results of other disciplines and to try to make a minimal loss.
In 2013, we considered unconventional layouts like the “Flying Wing” where the noise is screened throughout the airframe. Research of aircraft design with engines located on top of the fuselage was carried out, and, of course, we continued to work on the layouts of traditional aircraft forms.
Work in all these areas was carried out in the past year and will be continued in the future. There are no definitive answers regarding what will be the future aircraft. All potential practices will be employed when deciding on the next generation aircraft.
We also worked a lot on new designs not only of long-haul aircraft, but also on regional jets. In particular, an interesting solution in this area was studied — subsonic executive aircraft with the original name “Golovastik” (Tadpole). It solved one of the issues of regional aircraft, namely passenger comfort. Comfort here is ensured primarily by the large size of the fuselage (cabin height is more than 1.9 m). Golovastik is a plane with a special teardrop-shaped fuselage, spacious enough for passengers, able to fly at high speeds with good aerodynamic efficiency.
Calculation of flow of the prospective executive aircraft.
Limiting airflow lines figure
The second FTP contract is R&D “Transport,” consisting of two areas: subsonic transport aircraft and supersonic business aircraft.
An important event happened in the past year in the first area: it was decided to resume work on the light transport aircraft IL-112. Its launch is scheduled for 2015, and now the scope of work is being formed in order to start series production of the aircraft. Of course, our staff has done a lot for this anything-but-simple aircraft. Taking into account the large dimensions of the fuselage and the types of cargo to be carried, we need to make it aerodynamically efficient. This is a contradictory requirement that we have been negotiating for several years. Now, all these works are being resumed at TsAGI.
Also in the field of subsonic aircraft we considered more efficient layout with advanced basing features, for example, on unprepared sites.
Another area of the “Transport” R&D contract is a supersonic business aircraft. Work of the past year was mainly related to the research of opportunities for application of power plants with specific configurations. In this regard, requirements for supersonic aircraft differ significantly from the requirements for subsonic aircraft in terms of acoustic characteristics. If for a subsonic civil aircraft, low noise level can be achieved using high bypass engines, for supersonic aircraft it is impossible due to aerodynamics reasons. It is necessary to ensure their high efficiency and acceptable acoustics. Here we work with a number of subcontractors, including CIAM, aircraft engine design bureaus, etc. Of course, this is not very near future, but the problem of our Institute and the complex is to create a backlog for the benefit of the future.
A test bench for research of prospective high-speed helicopter in the ADT T-104
Finally, the third major project of FTP — “Vzlet ” - refers to the helicopter category. Revolutionary changes are now taking place in the world helicopter industry: speeds are mentioned, once considered fantastic for rotorcraft, of
Now alternative arrangements are being examined, when part of the thrust is generated not by the rotor (like in existing machines), but by other components. TsAGI scientists and engineers have created a special large-scale test bench for research of unconventional layouts, where ways to create lift and thrust are separated.
Could you mention specific shifts in these projects in 2013?
A very important step in the research is experimental works. Of course, they are long and costly, but at the same time they represent an indicator of the level of technological readiness; not computational studies, but specific testing of demonstrator prototypes. And this year we were able to conduct a series of studies using experimental facilities of the Institute. That is, we can talk about bringing work to specific technical solutions in metal.
Sergey Vladimirovich, you are describing promising work, planned for the distant future. And what was the progress of the research of objects closer to our time in 2013?
Of course, we worked diligently on near-term projects presently in design offices as well. First and foremost, it’s the MS-21 aircraft. The layout of this aircraft has been frozen; its first flight is scheduled for 2015. However, we continue to work in this area: loads on controls are being clarified, local aerodynamics are being improved, etc.
The experts of the propulsion aerodynamics department, together with the staff of JSC Aviatsionny Dvigatel conducted thorough testing of the PD-14 engine nacelle for the MS-21, in particular, to ensure stable operation of the engine under all flight conditions.
The helicopter department is working quite successfully on the MS-21, addressing a special issue — altitude-airspeed performance measuring systems. This is an important aircraft system, which allows the pilot to get information about where he is, how fast and at what altitude he is flying, etc. We have a lot of experience in implementation of such systems for helicopters. This work is a welcome detail, confirming an integrated approach of our departments to the development of modern platforms.
Of course, the work on further improvement of the T-50 is being continued. However, this fighter is already flying; the scope of research on this aircraft has decreased. Talking about new military aircraft, there is a broad range of work on UAVs for all purposes — both scout and attack aircraft. In this area we cooperate with a number of design offices, involving a large range of professionals, both from Aerodynamics Complex and the entire TsAGI.
What were the achievements of experts of the Hypersonic Aircraft Aerothermodynamics Research Department?
Regarding this work, I would like to highlight two aspects. In addition to conducting fundamental research related to new ways to control flow around the aircraft, a large-scale work on icing is underway. This includes fundamental work on new hydrophobic coatings that will reduce adhesion (adhesion of ice to the surface) and facilitate the work of de-icing systems or allow to operate entirely without them. Such coating-related studies, with their chemistry and physics, are characterized as low readiness level works and are exploratory in nature. But there is a specific project related to the study of pitot icing — small, but very important aircraft elements.
In addition, a substantial amount of work is carried out by scientists on space topics. The major problem in this area is thermal processes and aerodynamic heating arising during airflow of the units. Our staff has to give answers to very complex issues related to thermal processes, heating of structures at high speeds. General progress in the field of aviation is greatly associated with the use of new materials, and this applies to all areas — both subsonic and supersonic aircraft, both civil and military aviation. However, for high-speed units the issue of materials is a crucial one. We must clearly understand resistance to heat and to know heating temperatures of a certain structure, to understand which materials can be used, and which can not.
How has international cooperation of the Complex’s experts developed in 2013?
As to international cooperation, I would like to mention one positive fact. This year we started a new way of cooperation with foreign partners, the so-called coordinated projects. Earlier we were associate contractors, and the projects were funded by European partners, who determined the content of the work. But coordinated projects represent a different form, where financing of each group of contractors is carried out by the relevant party, and coordination is to harmonize the work and exchange the results on a broad level. This is mutually beneficial cooperation, which makes us equal partners. In the last year TsAGI won some very serious tenders. Aerodynamic specialists are involved in a number of projects of the 7th European Framework Programme, but I wanted to mention two major projects launched in the last year.
The first project, Buterfli, seeking to explore new forms of flow control, started in October 2013. It is scheduled for three years. Our main partner in the project is ONERA (France).
The second project, “High-speed civilian aircraft” (HCA), is in a sense futuristic and ambitious project, with a very few similar projects implemented in the world to date. HCA, launched late last year, will last to 2015, and is focused on the study of very high-speed civil aircraft (M = 6) on hydrogen fuel. The project provides for broad cooperation with other organizations: from the Russian part it is primarily CIAM, from the foreign part it involves ONERA (France), DLR (Germany) and EADS (EU).
What would you like to wish the staff of the Complex in the coming year?
Of course, health and happiness in family and at work! I can say that we have everything to look forward with confidence. This includes new staff, promising areas of work, ever-increasing interest of the country’s leadership in aviation, which is expressed both in nature of projects and their quantity, and in funding volume. The main wish today for all of us is to be more optimistic!