THE PROBLEMS OF SELECTING THE POWER PLANT FOR LIGHT PROPELLER-DRIVEN AIRCRAFT AND UNMANNED AERIAL VEHICLE TAKING INTO ACCOUNT THE REQUIREMENTS FOR COMMUNITY NOISE

Akustika ◽  
2021 ◽  
pp. 162
Author(s):  
Petr Moshkov ◽  
Valery Samokhin ◽  
Alexey Yakovlev ◽  
Chen Bolun

The problem of selecting a propeller-driven power plant including a single propeller and a piston engine for an aircraft taking into account the requirements for community noise is considered. The competitively necessary community noise levels for light propeller-driven aircraft are formulated, focusing on which it is necessary to design modern aircraft that meet the current and future requirements of ICAO. Modern noise reduction technologies are considered and their effectiveness is evaluated. The main parameters when choosing a propeller are its diameter, the number of blades, the configuration (pusher or tractor) and the presence of a duct. When choosing a piston engine you should take into account the higher acoustic efficiency of two-stroke engines compared to fourstroke engines. The use of intake and exhaust mufflers, as well as sound-proofing hoods, significantly affects the mass and size restrictions, so the need to install mufflers and hoods should be determined at the preliminary design stage. The design mode for the design of light propeller-driven aircraft is the take-off power condition, for propeller unmanned aerial vehicle is maximum cruising level flight mode.

Structures ◽  
2021 ◽  
Vol 31 ◽  
pp. 395-405
Author(s):  
Arsalan Alavi ◽  
Elena Mele ◽  
Reza Rahgozar ◽  
Ehsan Noroozinejad Farsangi ◽  
Izuru Takewaki ◽  
...  

2021 ◽  
Vol 92 (10) ◽  
pp. 618-622
Author(s):  
Yu. A. Burtsev ◽  
A. V. Pavlenko ◽  
I. V. Vasyukov ◽  
V. S. Puzin ◽  
A. V. Zhivodernikov

Author(s):  
Hongbo Xin ◽  
Yujie Wang ◽  
Xianzhong Gao ◽  
Qingyang Chen ◽  
Bingjie Zhu ◽  
...  

The tail-sitter unmanned aerial vehicles have the advantages of multi-rotors and fixed-wing aircrafts, such as vertical takeoff and landing, long endurance and high-speed cruise. These make the tail-sitter unmanned aerial vehicle capable for special tasks in complex environments. In this article, we present the modeling and the control system design for a quadrotor tail-sitter unmanned aerial vehicle whose main structure consists of a traditional quadrotor with four wings fixed on the four rotor arms. The key point of the control system is the transition process between hover flight mode and level flight mode. However, the normal Euler angle representation cannot tackle both of the hover and level flight modes because of the singularity when pitch angle tends to [Formula: see text]. The dual-Euler method using two Euler-angle representations in two body-fixed coordinate frames is presented to couple with this problem, which gives continuous attitude representation throughout the whole flight envelope. The control system is divided into hover and level controllers to adapt to the two different flight modes. The nonlinear dynamic inverse method is employed to realize fuselage rotation and attitude stabilization. In guidance control, the vector field method is used in level flight guidance logic, and the quadrotor guidance method is used in hover flight mode. The framework of the whole system is established by MATLAB and Simulink, and the effectiveness of the guidance and control algorithms are verified by simulation. Finally, the flight test of the prototype shows the feasibility of the whole system.


1999 ◽  
Vol 36 (03) ◽  
pp. 171-174
Author(s):  
Hüseyin Yilmaz ◽  
Abdi Kükner

It is well known that stability is the most important safety requirement for ships. One should have some information on ship stability at the preliminary design stage in order to reduce risk. Initial stability of ships is an important criterion and can be closely evaluated in terms of form parameters and vertical center of gravity. In this study, using some sample ship data, approximate formulations are derived by means of regression analysis for the calculations expressed in terms of ship preliminary design parameters that can easily provide approximate GM calculations. Thus designers can be provided with ship stability at the preliminary design stage, and also a set of appropriate design parameters for improving vessel stability can easily be determined.


2021 ◽  
Author(s):  
Sacheen Bekah

This thesis presents the use of Finite Element (FE) based fatigue analysis to locate the critical point of crack initiation and predict life in a door hinge system that is subjected to both uni-axial and multi-axial loading. The results are experimentally validated. The FE model is further used to obtain an optimum design per the standard requirement in the ground vehicle industry. The accuracy of the results showed that FE based fatigue analysis can be successfully employed to reduce costly and time-consuming experiments in the preliminary design stage. Numerical analysis also provides the product design engineers with substantial savings, enabling the testing of fewer prototypes.


2021 ◽  
Author(s):  
Sacheen Bekah

This thesis presents the use of Finite Element (FE) based fatigue analysis to locate the critical point of crack initiation and predict life in a door hinge system that is subjected to both uni-axial and multi-axial loading. The results are experimentally validated. The FE model is further used to obtain an optimum design per the standard requirement in the ground vehicle industry. The accuracy of the results showed that FE based fatigue analysis can be successfully employed to reduce costly and time-consuming experiments in the preliminary design stage. Numerical analysis also provides the product design engineers with substantial savings, enabling the testing of fewer prototypes.


2015 ◽  
Vol 22 (1) ◽  
pp. 28-35
Author(s):  
Katarzyna Żelazny

Abstract During ship design, its service speed is one of the crucial parameters which decide on future economic effects. As sufficiently exact calculation methods applicable to preliminary design stage are lacking the so called contract speed which a ship reaches in calm water is usually applied. In the paper [11] a parametric method for calculation of total ship resistance in actual weather conditions (wind, waves, sea current), was presented. This paper presents a parametric model of ship propulsion system (screw propeller - propulsion engine) as well as a calculation method, based on both models, of mean statistical value of ship service speed in seasonal weather conditions occurring on shipping lines. The method makes use of only basic design parameters and may be applied in preliminary design stage.


1995 ◽  
Vol 11 (04) ◽  
pp. 252-263
Author(s):  
Walter L. Christensen ◽  
Philip C. Koenig

Standard outfit package units for reverse osmosis plants, fire pumps, steering gear, and sanitary spaces were proposed for the LPD 17 amphibious transport dock ship design. The ship was in the preliminary design stage, and it was necessary to determine how this shift to outfit modularity would affect the ship procurement program. Because the use of package units would not have a significant impact on the overall characteristics and performance of the ship, the focus of the investigation was on material ordering and production scheduling. The analysis took account of zone-area-stage outfitting methods and also more traditional practices. With either approach, it was found that the package units did not present any schedule or procurement problems This particular study was focused on a very specific issue, but the approach is applicable to a wide range of production impact assessment problems.


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