Models of Transonic Flows
New Dynamic Models of Unsteady Viscous Transonic Aerodynamics
Tech Area / Field
- PHY-NGD/Fluid Mechanics and Gas Dynamics/Physics
3 Approved without Funding
Central Aerodynamic Institute, Russia, Moscow reg., Zhukovsky
- University of Southern California, USA, CA, Los-Angeles\nIowa State University, USA, IA, Ames\nUniversity of Delaware, USA, DE, Newark\nRensselaer Polytechnic Institute, USA, NY, Troy
Project summaryThe objective of this project is to develop efficient mathematical models of unsteady transonic flow. They are necessary for determination of aerodynamic forces and moments on an aircraft when standard quasi-steady approach fails. The modern civil airplane has high subsonic cruise flight Mach number and supercritical airfoils,.it leads to the complex unsteady flow field which contains the shock waves and the local separation zones. When dynamic maneuvers or moving in gust, within dynamic stall, vortex breakdown, shock induced boundary layer separation, and so on the aerodynamic load depends both on current kinematic parameters and time history of the motion. The well-known non-linear indicial response approach for aerodynamic loads formulation needs a lot of data and presents a considerable challenge to its application. Therefore, we propose the forces variation to be modeled by a dynamic system with parameters determined by identification of experimental data. Such a method has been employed for calculation of the fighter aircraft maneuver, and one of the project goals is to spread it to the civil aircraft problems. The method will be complemented by identification of numerical data. New numerical method of the unsteady transonic viscous flows will be developed for these computations. Standard Navier-Stokes methods do not suffice at high Reynolds numbers even for steady flows. Therefore new one has to be elaborated using a theory of viscous-inviscid interaction. Such work has been successfully carried out by our team in the case of steady flow around an airfoil. We plan to spread that to the unsteady problems. The first stage will be restricted by two-dimensional problems. The investigation proposed allows us to study several features of unsteady transonic flows and to create dynamic models for these phenomena. These models are sure to be useful when airplane designing because accurate description of forces and moments increases both the safety flight region and the effectiveness of the airplane.
Expected results are:
- The dynamic models of unsteady transonic flows at high Reynolds numbers will be developed for determination of aerodynamic loads on the civil airplane at off-design flight conditions.
- The models will be used for elaboration of the applied program package for estimation of the safe flight boundaries.
- It will be demonstrated by comparison with experimental data that the method of dynamic model can be applied for accurate determination of the safe flight boundary in several cases and it is possible to use the method within designing of the new plane generation.
The conviction of the project goal fulfillment is based on high scientific level of the team members. The team consists of 5 highly qualified specialists (three Doctors of Science and two PhD), 3 mid-level specialists and 2 junior-level (post graduate students). Members of the team have six national N.E. Zhukovsky awards in competitions of the best research works in aeronautics. Previously they all (excluding the post graduate students) took part in investigation and development of nuclear weapons deliveries.
The participants of the project are well-known in aeronautical community, many their published works are cited and their results and methods are used by several authors. There are good scientific relations with the foreign scientists, working in the area of the project. Namely, with: Dr. M. Barnett (UTRC, USA), Prof. H.K. Cheng (USC, USA), Prof. J. Cole (RPI, USA), Dr. J. Edvards and Dr. V. Klein (NASA LaRC, USA), Dr. D. Greenwell and Dr. J. Gibb (DERA Bedford, UK), Dr. N. Malmuth (RISC, USA), Dr. P. Perrier (Dassault Aviation, France).
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