New Configurations of Airplane Elements
Investigation of Aerodynamic, Structural and Technological Aspects of New Configurations of Airplane Elements and their Conversion Application
Tech Area / Field
- SAT-AER/Aeronautics/Space, Aircraft and Surface Transportation
3 Approved without Funding
Moscow Institute of Physics and Technology, Russia, Moscow reg., Dolgoprudny
- AO Double Spiral, Russia, Moscow reg., Zhukovsky
- ONERA, France, Toulouse\nAIRBUS Industrie / ET Engineering Directorate, France, Blagnac\nUniversität-GH Siegen / FOMAAS, Germany, Siegen
Project summaryThe objects of the "Investigation of aerodynamic, structural, and technological aspects of new configurations of airplane elements and their conversion application" project are theoretical and experimental studies of nonlinear phenomena of continuum mechanics and development of series airplane elements (winglets, frames), industrial equipment and every day devices (working units of mixers, whisks of mixers). As a basis for this devices will be the elements with configuration of the one-sided surfaces of Moebius strip-type (elements of "one-sided topology") which (on the preliminary studies) have a number of the features and the advantages.
The project proposed consists of three stages. At the first stage problems of improving aerodynamic characteristics of airplane wing, at the second one problems of improving the structural and stiffness characteristics of main load-carrying elements and at the third stage problems of improving efficiency of the industrial and household mixers are solved. The common moment for all these stages is the use of surfaces of one-sided topology (Moebius strip-type) in the main structural elements.
The use of the common component, the Moebius band, is dictated by reason that the "stability plateau" (see Fig. 1) which is observed in various continuum mechanics disciplines (including aerodynamics, elasticity theory etc.) may be explained by the external work being spent to "cement" the monopoles into dipoles; this phenomenon may occur naturally (for example, the flow downstream of a cylinder) or be forced (for example, the flow downstream of a one-sided surface similar to the Moebius band).
In particular, when an airframe includes one-sided components (such as the wing tip devices, Fig. 2) the flow energy is not spent to intensify tip vortices (which is the case for usual wings) but forms a dual-vortex structure in which the vortices interact in a nonlinear way. In this case the wake removes less energy, the flow is moving transversely (with respect to the main stream) - this is like lengthening the wing and/or the winglets, so the induced drag becomes decreased (and the lift-to-drag ratio, increased).
When the one-sided surface is inserted into the load-carrying structure, the external force is taken by the structure more efficiently (all of the material is involved; stress diagrams are more uniform); this improves strengths, stiffnesses, and stability data while maintaining the structural weight (or decreases weight while meeting the strength requirements.)
For instance, experiments with simplified Moebius-type strong frame models (Fig. 3) provided evidence of there existing a load mode for which the stress diagram over the frame contour is notably uniform.
In this case, the external load is "spent" to transform a particular deformation mode into another one - exchange between normal and shear stresses. It is this effect that makes the stress diagrams more uniform, lowers their maximum values, and increases the load-carrying capability.
Proceeding by analogy with the novel method for reducing the wing induced drag, a new approach to the mixing energy consumption reduction is proposed; it is based on closing the high-pressure domains onto the low-pressure domains over blades that have a one-sided surface of Moebius-band type. In this case the transverse velocity gradients (or, equally, shear stress) in the medium treated are established directly: by forming the shear flows over the one-sided blade surface; therefore, mixing holds within a much larger volume. As for energy, high efficiency of such technology is due to the lower power requirement of maintaining the shear flow over the blade (the energy-saving approach.)
Each of the three sections of the project is supported by results of analytical studies and lab tests. In-depth investigation into physics of the phenomena-taking place around the one-sided surfaces requires additionally studying the features by using both the experiments and math modeling (including large-scale computation.)
Experiments are assumed to be conducted in wind tunnels and strength test facilities of TsAGI and Tupolev Design Bureau, as well as at the Michurinsk PROGRESS factory and the Samara synthetic alcohol plant.
The project is anticipated to
- Reveal the physics of the effects holding in and around the one-sided surfaces used as components of (1) lifting and load-bearing elements and (2) blades for single-mode and multimode mixers,
- Outline conditions of the one-sided surfaces being efficient,
- Develop methods and programs for computer modeling of complicated vortical flows corresponding to "supercritical" (stall) flows about traditional lifting systems.
These effects and results should become the basis for preparing the patent applications.
Involved as a collaborator is expected to be the Aviation Partners Company (Seattle) that holds scientific contacts with Double Spiral for two years; the company expressed its intention in the letter to Mr. O.Lomacky, Executive Director ISTC.
The study subject proposed by MFTI and Double Spiral is of scientific interest and practical importance and, of course, will appeal the specialists. Competence of both MFTI and Double Spiral leaves no room for doubt in positive results being imminent.
All concerned persons and organizations are invited to cooperate.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.