Abstract
This paper presents calibration of flush air data sensing systems during ascent period of a satellite launch
vehicle. Aerodynamic results are numerically computed by solving three-dimensional time dependent compressible
Euler equations over a payload shroud of a satellite launch vehicle. The flush air data systemconsists of four pressure
ports flushed on a blunt-cone section of the payload shroud and connected to on board differential pressure transducers. The inverse algorithm uses calibration charts which are based on computed and measured data. A controlled random search method coupled with neural network technique is employed to estimate pitch and yaw angles from measured transient differential pressure history. The algorithm predicts the flow direction stepwise with the function of flightMach numbers and can be termed as an onlinemethod. Flow direction of the launch vehicle is compared with the reconstructed trajectory data. The estimated values of the flow direction are in good agreement with them.
Key Words
glass structures; impact load; pendulum test
Address
R.C. Mehta: Department of Aeronautical Engineering, Noorul Islam Centre for Higher Education, Kumaracoil 629180, India
Abstract
This paper discusses an improved unmanned aerial vehicle, UAV, configuration characterized by telescopic booms to optimize the flight mechanics and fuel consumption of the aircraft at various loading/flight conditions. The starting point consists of a full-composite smaller UAV which was derived by a general aviation ultralight motorized aircraft ULM. The present design, named ToBoFlex, extends the two-booms configuration to a three tons aircraft. To adapt the design to needs relevant to different applications, new solutions were proposed in aerodynamic fields and materials and structural areas. Different structural solutions were reported. To optimize aircraft endurance, the innovative concept of Telescopic Tail Boom was considered along with two different tails architecture. A new structural configuration of the fuselage was proposed. Further consideration of hydrogen fuel cell electric propulsion is now being studied in collaboration between the Polytechnic of Turin and Prince Mohammad Bin Fahd University which could be the starting point of future investigations.
Key Words
electric propulsion; full composite aircraft; hydrogen fuel cell; structural design; UAV
Address
E. Carrera: Department of Mechanical and AeroSpace Engineering, Politecnico di Torino, c.so Duca degli Abruzzi, Torino, 10129, Italy; Deanship of Research, Prince Mohammad Bin Fahd University, P.O. Box 1664, Al Khobar 31952, Kingdom of Saudi Arabia
M. Verrastro: Leonardo Company, Piazza Monte Grappa n. 4, 00195 Rome, Italy
Alberto Boretti: Independent Scientist, Chancellor Avenue, 3083 Bundoora, Australia
Abstract
Instead of developing new guided missiles, converting unguided missile into guided ones by adding guidance and control kits has become a global trend. Of the most efficient and widely used thrust vector control (TVC) techniques in rocketry is the jet vanes placed inside the nozzle divergent section. Upon deflecting them, lift created on the vanes is transferred to the rocket generating the desired control moment. The present study examines the concept of using an add-on jet vane TVC kit to a plain nozzle. The impact of adding the kit with different vanes locations and deflection angles is numerically investigated by simulating the flow through the nozzle with the kit. Two hinge locations are examined namely, at 24% and 36% of nozzle exit diameter. For each location, angles of deflection namely 0o, 5o, 10o, and 15o are examined. Focus is made on variation of control force, thrust losses, lift and drag on vanes, jet inclination, and jet flow structure with TVC kit design parameters.
Key Words
add-on kit; CFD; jet vanes; Nozzle flow; Thrust vector control
Address
Mohamed G. AbuElkhier, Sameh Shaaban: Mechanical Engineering Department, College of Engineering and Technology-Cairo Campus, Arab Academy for Science, Technology and Maritime Transport (AASTMT), Cairo, Egypt
Mahmoud Y.M. Ahmed: Aerospace Engineering Department, Military Technical College, Cairo, Egypt
Abstract
The physical and mathematical foundations of the heat-shielding composite materials functioning under the conditions of aerodynamic heating of aircraft, as well as under the conditions of the point effect of high-energy radiation are considered. The problem of deformation of a thin shallow shell under the action of a local temperature field is approximately solved. Such problems arise, for example, in the case of local destruction of heat-protective coatings of aircraft shells. Then the aerodynamic heating acts directly on the load-bearing shell of the structure. Its destruction inevitably leads to the death of the entire aircraft. A methodology has been developed for the numerical solution of the entire complex problem on the basis of economical absolutely stable numerical methods. Multiple results of numerical simulation of the thermal state of the locally heated shallow shell under conditions of its thermal destruction at high temperatures have been obtained.
Key Words
composite materials; heat and mass transfer problems; influence functions; reusable space system; temperature field
Address
Boris A. Antufiev: Department of Resistance of Materials Dynamics and Strength of Machines, Moscow Aviation Institute (National Research University), Moscow, Russian Federation
Ying Sun: Department of Mechanical Engineering, Hangzhou Xiaoshan Technician College, Hangzhou Zhejiang, People's Republic of China
Olga V. Egorova: Department of Resistance of Materials Dynamics and Strength of Machines, Moscow Aviation Institute (National Research University), Moscow, Russian Federation
Nikolay M. Bugaev: Moscow Aviation Institute (National Research University), Moscow, Russian Federation
Abstract
Reduced graphene oxide (rGO) is one of the derivatives of graphene, which has drawn some experimental research interests in recent years however, numerical research studying the mechanical behaviors of composites made of rGO has not been taken into consideration yet. The objective of this research is to investigate the buckling, and free vibration of functionally graded reduced graphene oxide reinforced nanocomposite (FG rGORC) plates employing isogeometric analysis (IGA). The effective Young's modulus of rGORC is determined based on the Halpin-Tsai model. Four different FG distribution types of rGO are considered varying across plate thickness. Besides, the refined plate theory is used based on Reddy's third-order function. To capture the size effect, modified couple stress theory (MCST) is employed. A comprehensive study is provided examining the effect of various parameters including rGO weight fraction, FG distribution types, boundary conditions, material length scale parameter, etc. Our obtained results show that the addition of only 1% of uniformly distributed rGO into epoxy plates leads to the fundamental frequency and critical buckling load 18% and 39% higher than those of pure epoxy plates, respectively.
Key Words
buckling; free vibration; Isogeometric Analysis (IGA); Modified Couple Stress Theory (MCST); Reduced Graphene Oxide (rGO)
Address
Amir Farzam: Department of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, Iran; Department of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
Behrooz Hassani: Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
