Aerodynamic Analysis of a Supersonic Transport Aircraft at Landing Speed Conditions

Supersonic flight for commercial aviation is gaining a renewed interest, especially for business aviation, which demands the reduction of flight times for transcontinental routes. So far, the promise of civil supersonic flight has only been afforded by the Concorde and Tupolev T-144 aircraft. However, little or nothing can be found about the aerodynamics of these aeroshapes, the knowledge of which is extremely interesting to obtain before the development of the next-generation high-speed aircraft. Therefore, the present research effort aimed at filling in the lack of data on a Concorde-like aeroshape by focusing on evaluating the aerodynamics of a complete aircraft configuration under low-speed conditions, close to those of the approach and landing phase. In this framework, the present paper focuses on the CFD study of the longitudinal aerodynamics of a Concorde-like, tailless, delta-ogee wing seamlessly integrated onto a Sears–Haack body fuselage, suitable for civil transportation. The drag polar at a Mach number equal to 0.24 at a 30 m altitude was computed for a wide range of angles of attack (0∘,60∘), with a steady RANS simulation to provide the feedback of the aerodynamic behaviour post breakdown, useful for a preliminary design. The vortex-lift contribution to the aerodynamic coefficients was accounted for in the longitudinal flight condition. The results were in agreement with the analytical theory of the delta-wing. Flowfield sensitivity to the angle of attack at near-stall and post-stall flight attitudes confirmed the literature results. Furthermore, the longitudinal static stability was addressed. The CFD simulation also evidenced a static instability condition arising for 15∘≤α≤20∘ due to vortex breakdown, which was accounted for.

Wing Shape Optimization and Selecting Rational Re-Entry Trajectory for Reusable Spacecraft of Tourist Class

The article considers solving the interrelated problems of wing shape optimization and synthesis of the re-entry trajectory control law for the reusable spacecraft of tourist class. To ensure a high aerodynamic quality of the wing, increase its bearing properties, as well as improve the maneuverability and controllability of the spacecraft as a whole, the wing shape has been optimized for sub- and supersonic flight modes. The problem of minimizing the wing area is solved for subsonic flight speed while ensuring the level of lift sufficient for landing, with the introduction of restrictions on the minimum wing sweep angle. For supersonic flight speed, maximization of the aerodynamic quality of the wing is used as an objective function. The length and taper of the wing, leading-edge sweep angle, the size of the root and tip chords, and the position of the wing relative to the fuselage were chosen as variables. For the wing shape selected on the basis of the parametric analysis, the calculation of the dependences of the spacecraft aerodynamic coefficients on the Mach number, used for selecting a rational program for the descent control in the atmosphere, was carried out. The choice of a rational control program is made with restrictions on the level of overloads, kinetic pressure and maximum heat flux.

E-Commerce and Its Role in the Development of India's Indigenous Product Base

This work aims to fathom how the traditional and the indigenous product base of India will change if it rides the supersonic flight of the booming e-commerce sector. E-commerce has registered unprecedented growth in the developed world, and in the developing world, the transition is more visible and is garnering a foothold in a multitude of ways. Propelled by rising smartphone penetration, 4G networks, and increasing consumer wealth, the Indian e-commerce market is expected to grow significantly. Addendum to this will be the initiatives taken to indicate the transition. One such prospective sector that will ensure this is India's traditionally produced/manufactured or exclusive homegrown products. Linking these locally vibrant products or goods in states per se with e-commerce will ensure the growth and development of the said products and will stretch their outreach both in the country and worldwide. This in turn will ensure the development of the particular regions and the country as a whole apart from carving an undaunted place in the export portfolio of the country.

The effect of collimation on the dynamics of two meteoroid fragments of the same size

The article analyzes the problem of the supersonic flight of two meteoroid fragments of the same size in the framework of two-dimensional plane formulation using the multigrid method for modeling the dynamics of a system of bodies. Initially, the bodies followed each other with a slight displacement of the body located behind, perpendicular to the direction of motion. The variable parameter was the density of the body located behind. Collisions between bodies were calculated according to the formulas of perfectly inelastic impact without adherence of the bodies. It is shown that there are three different modes of system dynamics: spreading with forcing the leading body in the transverse direction, the oscillations of the lagging body in the trace of the leading body, and the gradual lagging the body located behind from the leading body. Depending on its density oscillations of the lagging body are either diverging in nature with its ejection on the head shock wave from the leading body, or of a damped nature with the ejection into the region of the far trace of the leading body. The configuration of the joint flight of bodies directly one after another is not realized.