|
|
|
|
Home>Products>Journal and Reviews>I.RE.AS.E.>Latest issue International Review of Aerospace Engineering - October 2011 (Vol. 4 N. 5) - Papers
International Review of Aerospace Engineering - Papers
Abstract -
Simulation of bending vibration effects on a two-stage launch vehicle
with heavy payload and design an adaptive control to reduce the flexible
behaviours are discussed in this paper. Copyright © 2011 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Flexible Launch Vehicle, Root Mean Square Method (RMS), Heavy Payload, Notch Filter, Bending Vibration.
Abstract - - This paper presents an autopilot system for controlling a prototype unmanned aerial vehicle (UAV). The hardware parts and software components of the system are discussed in detail. First, we will analyze the control process of the UAV and then proceed with the study of philosophy of PID controller as the fundamental concept in autopilot control for directing and navigating the UAV. We will then introduce the software and hardware structures of the proposed autopilot system individually. We used the TMS320F28335 chip (made by TI Company) in designing the structure of the hardware board. In order to provide numerous digital and analog input/outputs, we utilized two separate hardware parts in our autopilot system: the basic autopilot system (XDSP) and the XGPIO system. We employed "code composer studio V4.1" software for programming our autopilot system. The program is loaded into the XDSP board using the same software. This program is responsible for commissioning the hardware part as well as controlling the UAV itself. Finally, we will evaluate the performance of the system through running some performance tests on the hardware and software components of the autopilot system. The simulation results showed the integrity of the proposed system and proved the optimality of the design. Copyright © 2011 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Unmanned Aerial Vehicle (UAV), Autopilot Hardware, Autopilot Software, Code Composer Studio (CCS), Flight Control.
Abstract - Synthetic
jet actuators have shown good promise in delivering flow control for
several applications. However, in order to achieve the full potential
benefits of synthetic jets, the development of synthetic jet actuators
with higher momentum delivering capability is essential. Unsteady three
dimensional incompressible laminar numerical simulation was performed in
order to explore the benefits of four circular orifice synthetic jets
over a single one for higher circulation production. Flow features of
synthetic jets and the circulation of the vortex rings from with single,
two and four orifices are examined and compared in this paper. The
present study demonstrates that it is possible to increase circulation
by more than 3 times with as a result of having four orifices with
smaller diameters but higher dimensionless stroke lengths using four
orifice actuators.
Keywords: Synthetic Jet Actuators, Numerical.
Abstract - All space transportation systems are based on the principle of momentum conservation of classical physics. Therefore, all space vehicles need fuel for their operation. The physics governing this propulsion principle severely limits the specific impulse and/or available thrust. Only with novel physical principles, providing the proper engineering principles for propellantless propulsion, can these limits be overcome. The concept of gravity-like field propulsion represents such a novel principle. These fields would not be generated by the movement of extremely large masses (e.g., planets or stars). Instead, devices working similar to electromagnetism would be producing gravitational acceleration fields. The novel physical principle behind these devices stems from their direct interaction with the surrounding spacetime field. Current theoretical and experimental concepts pertaining to the physics of gravity-like fields are discussed together with recent experiments of producing extreme gravitomagnetic fields, performed at the Austrian Institute of Technology (AIT). The fundamental theoretical concepts of the Poly-Metric Tensor approach, PMT, are presented in a non-mathematical way, and, by further applying its physical concepts, it is argued that, in contrast to the circumferential gravity-like field observed in the experiments at AIT, axial gravity-like fields parallel to the axis of rotation of the cryogenic disk might be producible, strong enough for general propulsion purposes. Copyright © 2011 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Six Fundamental Physical Forces, Three Gravitational Fields, Ordinary and Non- Ordinary Matter, MOND, Generation of Gravity-Like Fields in the Laboratory, O(8,q) quaternion groups, Interaction Between Electromagnetism and Gravitation, Propellant- less Propulsion, Poly-Metric Tensor approach (PMT), Direct Energy Generation.
Abstract - In this paper comparative analysis of jet co-flow and Modified jet co- based injection in supersonic/hypersonic combustion of hydrogen has been presented. Coupled implicit scheme with finite rate chemistry model and K-ε and LES Turbulence model have been used for modeling of Scramjet combustion. The combustor has a single fuel injection parallel to the main flow from the base. The main issue in supersonic combustion is proper mixing within short burst of time. Because of the step on the top wall of the combustor, there exists an expansion fan generated just on the top wall at the entrance of the combustor, which is interacts with the oblique shock wave formed upstream of the combustor due to the shear layer deflecting into the core flow. The static pressures along the walls are normalized by the static pressure of the core flow. The stagnation temperature in the combustion reaches up to 2800 K. Fluctuation in pressure and Mach number was due to shock train. The present work is to combine the characteristics of the jet and strut, here named as modified jet based combustion. The comparison with jet it shows improved combustion efficiency while increase in total pressure loss. By increasing the jet- strut injection angle there is retardation in flow and also in combustion. The maximum angle can be taken up to 3 degree. Copyright © 2011 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: supersonic combustion, K-ε model, LES Model, stagnation temperature, flame speed, Mach number.
|
|
Please send any questions about this web site
to
info@praiseworthyprize.com
|
