31 research outputs found
Aerodynamic Modeling for Post-Stall Flight Simulation of a Transport Airplane
The file attached to this record is the author's final peer reviewed version.open access articleThe principles of aerodynamic modeling in the extended flight envelope, which is characterized by the development of separated flow, are outlined and illustrated for a generic transport airplane. The importance of different test techniques for generating wind tunnel data and the procedure for blending the obtained experimental data for aerodynamic modeling are discussed. Complementary use of computational fluid dynamics simulations reveals a substantial effect of the Reynolds number on the intensity of aerodynamic autorotation, which is later reflected in the aerodynamic model. Validation criteria for an extended envelope aerodynamic model are discussed, and the important role of professional test pilots with post-stall flying experience in tuning aerodynamic model parameters is emphasized. The paper presents an approach to aerodynamic modeling that was implemented in the project Simulation of Upset Recovery inAviation (2009–2012), funded by the EuropeanUnion under the seventh framework programme. The developed post-stall aerodynamic model of a generic airliner configuration for a wide range of angles of attack, sideslip, and angular rate was successfully validated by a
number of professional test pilots on hexapod and centrifuge-based flight simulator platforms
Demonstration of a parity-time symmetry breaking phase transition using superconducting and trapped-ion qutrits
Scalable quantum computers hold the promise to solve hard computational
problems, such as prime factorization, combinatorial optimization, simulation
of many-body physics, and quantum chemistry. While being key to understanding
many real-world phenomena, simulation of non-conservative quantum dynamics
presents a challenge for unitary quantum computation. In this work, we focus on
simulating non-unitary parity-time symmetric systems, which exhibit a
distinctive symmetry-breaking phase transition as well as other unique features
that have no counterpart in closed systems. We show that a qutrit, a
three-level quantum system, is capable of realizing this non-equilibrium phase
transition. By using two physical platforms - an array of trapped ions and a
superconducting transmon - and by controlling their three energy levels in a
digital manner, we experimentally simulate the parity-time symmetry-breaking
phase transition. Our results indicate the potential advantage of multi-level
(qudit) processors in simulating physical effects, where additional accessible
levels can play the role of a controlled environment.Comment: 14 pages, 9 figure
Ultrastrong photon-to-magnon coupling in multilayered heterostructures involving superconducting coherence via ferromagnetic layers
The critical step for future quantum industry demands realization of efficient information exchange between different-platform hybrid systems that can harvest advantages of distinct platforms. The major restraining factor for the progress in certain hybrids is weak coupling strength between the elemental particles. In particular, this restriction impedes a promising field of hybrid magnonics. In this work, we propose an approach for realization of on-chip hybrid magnonic systems with unprecedentedly strong coupling parameters. The approach is based on multilayered microstructures containing superconducting, insulating, and ferromagnetic layers with modified photon phase velocities and magnon eigenfrequencies. The enhanced coupling strength is provided by the radically reduced photon mode volume. Study of the microscopic mechanism of the photon-to-magnon coupling evidences formation of the long-range superconducting coherence via thick strong ferromagnetic layers in superconductor/ferromagnet/superconductor trilayer in the presence of magnetization precession. This discovery offers new opportunities in microwave superconducting spintronics for quantum technologies
Preservation of Soil Fertility Using Sidereal Clover
This study examined the use of intermediate groundcover sideral crops, such as perennial leguminous herbs, to conserve soil fertility though enriching the soil with fresh organic matter, an effective and low-cost method. Studies show that the use of direct sowing technology allows the preservation of all plant residues on the soil surface, which ensures the best accumulation of snow in the winter. Through the preservation of numerous biodrenes from the root system of sweet clover and other cultivated crops, as well as soil channels from earthworms, this direct sowing technology increases the moisture content of the soil and reduces moisture loss. The effectiveness of various soybean, corn and sunflower cultivation technologies with a minimal tillage period was studied. When sweet clover was used for green manure in April, the maximum yield was obtained, and the maximum yield for corn (57.3-82.3 c/ha) was obtained using the no-till technology. As a consequence, the ground cover crop had a noticeable effect on the yield of the second crop rotation - spring wheat, which had a higher yield. The use of direct sowing technology with sweet clover as green manure provided the highest yield of spring wheat - from 37.2 to 39.8 c / ha. The grain quality of spring wheat, placed as the second crop after melilot on green manure, was higher, both under no-till technology and under mini-till technology.
Keywords: biologization, soil fertility, green manure, clover, direct sowing, productivit
Aircraft dynamics at high incidence flight with account of unsteady aerodynamic effects.
An invited paper with the results of collaboration between TsAGI, Russia and DMU, UK, funded by DERA/QinetiQ, Bedford UK. The phenomenological approach formulated to nonlinear unsteady aerodynamics modelling is adopted in DLR/Germany (R.V. Jategaonkar [email protected]), ADA/India (Program Director T. G. Pai [email protected] ), presented in “Aircraft System Identification: Theory and Practice” by V.Klein and E.A.Morelli, AIAA Education Series, 2006, pp.484 (see p.59 and 72). The experimental technology for real-time unsteady loads measurements using hot-film sensors has been “...inspired by Goman and Khrabrov’s work…” (see NASA/TM-2004-212854, pp. 3-4, http://www.nasa.gov/centers/dryden/pdf/88785main_H-2568.pdf).An adequate modelling of nonlinear and unsteady aerodynamics at high incidence flight
is important for design of future agile and stealth fighters as well as for improved prediction
of high angle of attack dynamics of normal aircraft configurations.
The limitations for conventional aerodynamic model based on aerodynamic derivatives
concept are analyzed considering the longitudinal motion of a hypothetical aircraft with
the 65 degree delta wing and thrust vectoring control.
The dynamic unsteady aerodynamic model approximating the vortical and separated
flow time lag effects is considered along with the conventional aerodynamic model and
their impact on aircraft dynamics and control law design is discussed
Cation-Dependent Self-assembly of Vanadium Polyoxoniobates
Reaction of Na7H[Nb6O19]·15H2O with NaVO3·2H2O at 220 °C in the presence of NaHCO3 gives new bicapped α-Keggin vanadododecaniobate [VNb12O40{NbO(CO3)}2]13–, isolated and structurally characterized as Na9H4[VNb12O40{NbO(CO3)}2]·37H2O (1). According to 51V NMR and ESI-MS data, this anion equilibrates in solution with [VNb12O40]15– and oligomeric species that result from dissociation of the {NbO(CO3)}+ fragments. In the presence of potassium, the same reaction gives [VxNb24O76]n− (x = 4, n = 12 (2a); x = 3, n = 17 (2b)). The anions with x = 3 and 4 cocrystallize together, but exist as separate entities both in solid and in solution according to 51V MAS NMR and ESI-MS data
Investigation of Attainable Equilibrium Sets for Clearance of Flight Control Laws
A systematic investigation of aircraft equilibrium states and their local stability characteristics is used for clearance of flight control laws for a large variety of manoeuvres. The proposed approach is illustrated by clearance of the LPV control laws designed in a wide subsonic region for the F-18HARV aircraft in level flight conditions and clearance of the F-16 aircraft longitudinal and lateral-directional stability augmentation system for high range of incidence and intensive velocity roll rotation
Pushing Ahead - SUPRA Airplane Model for Upset Recovery
One of the primary objectives of the European Union 7th Framework Program research project SUPRA – “Simulation of Upset Recovery in Aviation” – is the development and validation of the aerodynamic model of a generic large transport airplane aimed for piloted simulation in the post-stall region and upset recovery training. Modeling methods for prediction of post-stall flight dynamics, use of the wind tunnel data from different experimental facilities complemented by CFD analysis, validation criteria, nonlinear dynamics investigation and piloted simulation results are presented in this paper. The aerodynamic model was successfully validated by a number of expert pilots and found acceptable for upset recovery training