scholarly journals Study on Optimization for High Lift Devices of Civil Aircraft Based on Rapid Calculation Method

2021 ◽  
Vol 1875 (1) ◽  
pp. 012009
Author(s):  
Jun Mao ◽  
Yingchun Chen
Keyword(s):  
Calculation Method ◽  
High Lift ◽  
Rapid Calculation ◽  
Civil Aircraft

Research on Designing Optimum Asphalt Content of Asphalt Mixture by Calculation and Experimental Method

2011 ◽  
Vol 97-98 ◽  
pp. 23-27
Author(s):  
Wen Fang Liu ◽  
Hong Mei Li ◽  
Bei Ping Tian
Keyword(s):  
Experimental Method ◽  
Calculation Method ◽  
Asphalt Mixture ◽  
Test Efficiency ◽  
Marshall Test ◽  
Rapid Calculation ◽  
Asphalt Content ◽  
Hot Mixed Asphalt

In this paper, the initial asphalt content is estimated by the hot-mixed asphalt mixture rapid calculation method in condition that we have no information about the similar project, and five asphalt content are selected with regarding the estimated asphalt content as the middle value, then carries on the Marshall test. The optimuml asphalt content is very accurate by the calculation and experimental method, the method greatly improved the test efficiency.

A rapid stress calculation method for short flexspline harmonic drive

2019 ◽  
Vol 36 (6) ◽  
pp. 1852-1867 ◽  
Author(s):  
Shuang Wang ◽  
Gedong Jiang ◽  
Xuesong Mei ◽  
Chuang Zou ◽  
Xian Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Calculation Method ◽  
Circumferential Stress ◽  
Element Model ◽  
Analytical Relationship ◽  
Analysis Method ◽  
Content Type ◽  
Stress Calculation ◽  
Mechanics Analysis ◽  
Rapid Calculation

Purpose Because of the compact structure, short flexspline (FS) harmonic drive (HD) is increasingly used. The stress calculation of FS is very important in design and optimization of HD system. This paper aims to study the stress calculation methods for short FS, based on mechanics analysis and finite element method (FEM). Design/methodology/approach A rapid stress calculation method, based on mechanics analysis, is proposed for the short FS of HD. To verify the stress calculation precision of short FS, a complete finite element model of HD is established. The results of stress and deformation of short FS in different lengths are solved by FEM. Findings Through the rapid calculation method, the analytical relationship between circumferential stress and length of cylinder was obtained. And the circumferential stress has proportional relation with the reciprocal of squared length. The FEM results verified that the rapid stress calculation method could obtain accurate results. Research limitations/implications The rapid mechanics analysis method is practiced to evaluate the strength of FS at the design stage of HD. And the complete model of HD could contribute to improving the accuracy of FEM results. Originality/value The rapid calculation method is developed based on mechanics analysis method of cylinder and equivalent additional bending moment model, through which the analytical relationship between circumferential stress and length of cylinder was obtained. The complete three-dimensional finite element model of HD takes the stiffness of bearing into consideration, which can be used in the numerical simulation in the future work to improve the accuracy.

Rapid calculation of the pressures and clearances in rough, rolling-sliding elastohydrodynamically lubricated contacts. Part 1: Low-amplitude, sinusoidal roughness

2007 ◽  
Vol 221 (5) ◽  
pp. 535-549 ◽  
Author(s):  
C J Hooke ◽  
K Y Li ◽  
G Morales-Espejel
Keyword(s):  
Surface Roughness ◽  
Rough Surface ◽  
Perturbation Analysis ◽  
Curve Fitting ◽  
Calculation Method ◽  
The Third ◽  
Lubricated Contacts ◽  
Rapid Calculation ◽  
Low Amplitude ◽  
Rough Rolling

Surface roughness in elastohydrodynamically lubricated (EHL) contacts may have a significant effect on component life and there is a need to be able to assess its effects quickly. This article describes a rapid calculation method, which provides accurate results where the amplitude of the roughness is relatively low and which gives good indications of the likely behaviour for higher amplitudes. In the first part, the effect of low-amplitude, sinusoidal roughness is examined, and it is shown that the behaviour can, for any wavelength and roughness orientation, be characterized by three complex quantities. Calculation of two of these is straightforward; the third requires curve fitting to the results obtained using a perturbation analysis. Details of the process are given. The second part of the article discusses how these results can be used to predict the behaviour of any rough surface under rolling-sliding EHL conditions.

scholarly journals High-fidelity simulations of unsteady civil aircraft aerodynamics: stakes and perspectives. Application of zonal detached eddy simulation

2014 ◽  
Vol 372 (2022) ◽  
pp. 20130325 ◽  
Author(s):  
Sébastien Deck ◽  
Fabien Gand ◽  
Vincent Brunet ◽  
Saloua Ben Khelil
Keyword(s):  
Turbulent Flows ◽  
Hybrid Methods ◽  
Landing Gear ◽  
High Fidelity ◽  
Detached Eddy Simulation ◽  
High Lift ◽  
Eddy Simulation ◽  
Civil Aircraft ◽  
Aircraft Aerodynamics ◽  
Transonic Buffet

This paper provides an up-to-date survey of the use of zonal detached eddy simulations (ZDES) for unsteady civil aircraft applications as a reflection on the stakes and perspectives of the use of hybrid methods in the framework of industrial aerodynamics. The issue of zonal or non-zonal treatment of turbulent flows for engineering applications is discussed. The ZDES method used in this article and based on a fluid problem-dependent zonalization is briefly presented. Some recent landmark achievements for conditions all over the flight envelope are presented, including low-speed (aeroacoustics of high-lift devices and landing gear), cruising (engine–airframe interactions), propulsive jets and off-design (transonic buffet and dive manoeuvres) applications. The implications of such results and remaining challenges in a more global framework are further discussed.

1305 Aerodynamic Design Optimization of Low Noise High-Lift Airfoil for Civil Aircraft

2013 ◽  
Vol 2013.23 (0) ◽  
pp. _1305-1_-_1305-10_
Author(s):  
Ryu SHINOMIYA ◽  
Masahiro KANAZAKI ◽  
Mitsuhiro MURAYAMA ◽  
Kazuomi YAMAMOTO
Keyword(s):  
Design Optimization ◽  
Low Noise ◽  
Aerodynamic Design ◽  
High Lift ◽  
Aerodynamic Design Optimization ◽  
Civil Aircraft

Esso Energy Award Lecture, 1987 - Application of aerodynamic research and development to civil aircraft wing design

1988 ◽  
Vol 416 (1850) ◽  
pp. 43-62
Keyword(s):  
Technological Progress ◽  
Computational Fluid Mechanics ◽  
Aerodynamic Design ◽  
Wing Design ◽  
High Lift ◽  
Business Jet ◽  
Civil Aircraft ◽  
Research Programmes ◽  
The Government

In the late 1950s the aerodynamicists at what is now the Hatfield site of British Aerospace accepted the challenge and met British European Airways’ demand for a 600 m. p. h. ( ca . 966 km h -1 ) short-haul jet airliner (the Trident). The experience and organization resulting from that project was the cornerstone on which the subsequent success story of civil wing design has been built. The substantial advances in efficiency achieved by the Hatfield team in the following designs for the 125 Business Jet, the 146 Feederliner and for the Airbus Industrie family of Wide-Body Mainline aircraft, has been supported by research programmes in the government establishments and universities as well as industry itself. Each project had its individual demands for fuel economy, high lift capability and structural efficiency, with commercial competition continually driving technological progress. The major highlights and achievements of the aerodynamic development programmes for these projects are reviewed. Turning to the present, the Hatfield team are currently working on the aerodynamic design for the combined Airbus A330/340 project. Technological progress continues apace with major investment in computational fluid mechanics, but the still essential role of experimental test techniques and facilities is emphasized.

scholarly journals Numerical investigation of porous materials for trailing edge noise reduction

2020 ◽  
Vol 19 (6-8) ◽  
pp. 347-364
Author(s):  
Lennart Rossian ◽  
Roland Ewert ◽  
Jan W Delfs
Keyword(s):  
Noise Reduction ◽  
Porous Materials ◽  
Collaborative Research ◽  
Smooth Transition ◽  
Trailing Edge ◽  
High Lift ◽  
Trailing Edge Noise ◽  
Numerical Investigations ◽  
Civil Aircraft ◽  
Numerical Approaches

In the framework of the German Collaborative Research Center CRC 880: Fundamentals of High Lift for Future Civil Aircraft porous materials as a means towards the reduction of airfoil trailing edge noise are investigated. At DLR, both experimental and numerical approaches are pursued to understand the physics behind the noise reduction. The present paper focuses on the numerical investigations, for which the experimental data serves as an evaluation basis. From the analysis of homogeneous materials, first steps are made towards the design of aeroacoustically tailored materials. It is assumed that materials with locally varying permeability may be suitable to achieve maximum noise reduction, as they provide a smooth transition from the solid airfoil to the free flow in the wake. The simulation results support this understanding, however it is revealed that high local gradients in the material properties themselves may act as acoustic sources.

Rapid calculation method for wave-guide-immersed dielectric resonant frequencies

2006 ◽  
Vol 84 (4) ◽  
pp. 289-297 ◽  
Author(s):  
Rudolf Nistor ◽  
Emil Petrescu
Keyword(s):  
Experimental Data ◽  
Calculation Method ◽  
Analysis Procedure ◽  
Wave Guide ◽  
Resonant Frequencies ◽  
Dielectric Sample ◽  
Margin Of Error ◽  
Rapid Calculation ◽  
Electrical Permittivity ◽  
Good Agreement

A rapid calculation is used to obtain the resonant frequencies of a dielectric sample excited in a semi-infinite wave guide. An analysis procedure for a sample excited in a semi-infinite wave guide is carried out to show the effect of the sample's dimensions and electrical permittivity. The theoretical resonant frequencies of the resonators are predicted and compared with those measured. The theoretical values of the resonant frequencies are in good agreement with experimental data within a margin of error less than 8%. PACS Nos.: 32.30.Bv, 41.20.Jb

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