scholarly journals Parametric Modeling of a Long-Range Aircraft under Consideration of Engine-Wing Integration

Aerospace ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 2
Author(s):  
Matthias Schulze ◽  
Jens Neumann ◽  
Thomas Klimmek
Keyword(s):  
Long Range ◽  
Parametric Modeling ◽  
Aeroelastic Stability ◽  
Aeroelastic Design ◽  
Flight Loads ◽  
Set Up ◽  
German Aerospace ◽  
Structural Mass ◽  
Mass Loads ◽  
Aircraft Configurations

The purpose of this paper is to investigate the influence of the engine position and mass as well as the pylon stiffness on the aeroelastic stability of a long-range wide-body transport aircraft. As reference configuration, DLR’s (German Aerospace Center/Deutsches Zentrum für Luft und Raumfahrt) generic aircraft configuration DLR-D250 is taken. The structural, mass, loads, and optimization models for the reference and a modified configuration with different engine and pylon parameters are set up using DLR’s automatized aeroelastic design process cpacs-MONA. At first, the cpacs-MONA process with its capabilities for parametric modeling of the complete aircraft and in particular the set-up of a generic elastic pylon model is unfolded. Then, the influence of the modified engine-wing parameters on the flight loads of the main wing is examined. The resulting loads are afterward used to structurally optimize the two configurations component wise. Finally, the results of post-cpacs-MONA flutter analyses performed for the two optimized aircraft configurations with the different engine and pylon characteristics are discussed. It is shown that the higher mass and the changed position of the engine slightly increased the flutter speed. Although the lowest flutter speeds for both configurations occur at a flutter phenomenon of the horizontal tail-plane outside of the aeroelastic stability envelope.

scholarly journals Using CFD to Evaluate Natural Ventilation through a 3D Parametric Modeling Approach

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2197
Author(s):  
Nayara Rodrigues Marques Sakiyama ◽  
Jurgen Frick ◽  
Timea Bejat ◽  
Harald Garrecht
Keyword(s):  
Natural Ventilation ◽  
Parametric Modeling ◽  
Cfd Simulations ◽  
3D Design ◽  
Post Process ◽  
Test House ◽  
Model Set ◽  
Computational Fluid Dynamics Cfd ◽  
Set Up ◽  
Passive Strategy

Predicting building air change rates is a challenge for designers seeking to deal with natural ventilation, a more and more popular passive strategy. Among the methods available for this task, computational fluid dynamics (CFD) appears the most compelling, in ascending use. However, CFD simulations require a range of settings and skills that inhibit its wide application. With the primary goal of providing a pragmatic CFD application to promote wind-driven ventilation assessments at the design phase, this paper presents a study that investigates natural ventilation integrating 3D parametric modeling and CFD. From pre- to post-processing, the workflow addresses all simulation steps: geometry and weather definition, including incident wind directions, a model set up, control, results’ edition, and visualization. Both indoor air velocities and air change rates (ACH) were calculated within the procedure, which used a test house and air measurements as a reference. The study explores alternatives in the 3D design platform’s frame to display and compute ACH and parametrically generate surfaces where air velocities are computed. The paper also discusses the effectiveness of the reference building’s natural ventilation by analyzing the CFD outputs. The proposed approach assists the practical use of CFD by designers, providing detailed information about the numerical model, as well as enabling the means to generate the cases, visualize, and post-process the results.

The Parametric Modeling and Contact Strength Analysis for the Wind Power Increasing Gear

2012 ◽  
Vol 522 ◽  
pp. 447-452
Author(s):  
Jing Luo ◽  
Mutellip Ahmat ◽  
Qiang Gao ◽  
Li Chao Ren
Keyword(s):  
Wind Power ◽  
Theoretical Basis ◽  
Optimization Design ◽  
3D Model ◽  
Parametric Modeling ◽  
Strength Analysis ◽  
Contact Strength ◽  
Set Up ◽  
Gear Contact ◽  
Designing Method

In this paper, the precise 3D model of the wind power increasing gear was set up by based on the parametric designing method of Pro/Program, then the contact strength of the gear was analyzed by the FEM and the Hertz theoretical value was calculated, the FEM and the Hertz results were contrasted in order to confirm the applicability of the numerical analysis in wind power gear contact analysis. Finally, the corresponding analysis conclusion was received.The researching results offered a effective theoretical basis for the optimization design and analysis of the wind increasing gear.

Uncertainty Quantification of Aeroelastic Stability

2014 ◽  
pp. 329-356 ◽  
Author(s):  
Georgia Georgiou ◽  
Hamed Haddad Khodaparast ◽  
Jonathan E. Cooper
Keyword(s):  
Uncertainty Quantification ◽  
Random Sampling ◽  
Expansion Method ◽  
Probability Density Functions ◽  
Fuel Load ◽  
Aeroelastic Stability ◽  
Aeroelastic System ◽  
Tunnel Model ◽  
Structural Mass ◽  
Kriging Predictor

The application of uncertainty analysis for the prediction of aeroelastic stability, using probabilistic and non-probabilistic methodologies, is considered in this chapter. Initially, a background to aeroelasticity and possible instabilities, in particular “flutter,” that can occur in aircraft is given along with the consideration of why Uncertainty Quantification (UQ) is becoming an important issue to the aerospace industry. The Polynomial Chaos Expansion method and the Fuzzy Analysis for UQ are then introduced and a range of different random and quasi-random sampling techniques as well as methods for surrogate modeling are discussed. The implementation of these methods is demonstrated for the prediction of the effects that variations in the structural mass, resembling variations in the fuel load, have on the aeroelastic behavior of the Semi-Span Super-Sonic Transport wind-tunnel model (S4T). A numerical model of the aircraft is investigated using an eigenvalue analysis and a series of linear flutter analyses for a range of subsonic and supersonic speeds. It is shown how the Probability Density Functions (PDF) of the resulting critical flutter speeds can be determined efficiently using both UQ approaches and how the membership functions of the aeroelastic system outputs can be obtained accurately using a Kriging predictor.

A Survey on Attacks and Defences on LoRaWAN Gateways

2021 ◽  
pp. 19-38
Author(s):  
Olof Magnusson ◽  
Rikard Teodorsson ◽  
Joakim Wennerberg ◽  
Stig Arne Knoph
Keyword(s):  
Internet Of Things ◽  
Long Range ◽  
Emerging Technology ◽  
The Internet ◽  
Area Network ◽  
Wide Area Network ◽  
Replay Attacks ◽  
Radio Signals ◽  
Iot Devices ◽  
Set Up

LoRaWAN (long-range wide-area network) is an emerging technology for the connection of internet of things (IoT) devices to the internet and can as such be an important part of decision support systems. In this technology, IoT devices are connected to the internet through gateways by using long-range radio signals. However, because LoRaWAN is an open network, anyone has the ability to connect an end device or set up a gateway. Thus, it is important that gateways are designed in such a way that their ability to be used maliciously is limited. This chapter covers relevant attacks against gateways and potential countermeasures against them. A number of different attacks were found in literature, including radio jamming, eavesdropping, replay attacks, and attacks against the implementation of what is called beacons in LoRaWAN. Countermeasures against these attacks are discussed, and a suggestion to improve the security of LoRaWAN is also included.

A Critical Review of German Long-Range Rocket Development

1946 ◽  
Vol 50 (427) ◽  
pp. 483-525 ◽  
Author(s):  
W. G. A. Perring
Keyword(s):  
Research And Development ◽  
Long Range ◽  
Critical Review ◽  
Set Up ◽  
The Cost

Serious rocket development was started in Germany in the years 1929–1930 by a few groups of private inventors. This work attracted the attention of the Army Weapons Group in 1933, and in 1937–1938 a special research and development station was set up at Peenemunde at the cost of 300 million marks, and the work was transferred from Berlin to this new station at about that time.

scholarly journals An airborne perfluorocarbon tracer system and its first application for a Lagrangian experiment

2014 ◽  
Vol 7 (7) ◽  
pp. 6791-6822
Author(s):  
Y. Ren ◽  
R. Baumann ◽  
H. Schlager
Keyword(s):  
Stratospheric Ozone ◽  
Lagrangian Model ◽  
Research Vessel ◽  
Gas Chromatography Mass Spectrometry ◽  
Sampling System ◽  
Tracer System ◽  
Research Aircraft ◽  
Set Up ◽  
German Aerospace ◽  
First Time

Abstract. A perfluorocarbon tracer system (PERTRAS), specifically designed for Lagrangian aircraft experiments, has been developed by the Deutsches Zentrum für Luft- und Raumfahrt (German Aerospace Center, DLR). It consists of three main parts: a tracer release unit (RU), an adsorption tube sampler (ATS) and a tracer analytical system. The RU was designed for airborne tracer release experiments; meanwhile, it can be used on various platforms for different experimental purpose (here research vessel). PERTRAS was for the first time applied in the field campaign Stratospheric ozone: halogen Impacts in a Varying Atmosphere (SHIVA) in November 2011. An amount of 8.8 kg perfluoromethylcyclopentane (PMCP) was released aboard the research vessel Sonne (RV Sonne) near the operational site of this campaign, Miri, Malaysia, on 21 November. The tracer samples collected using the ATS on board the DLR research aircraft Falcon were analyzed in the laboratory using a thermal desorber/gas chromatography/mass spectrometry (TD/GC/MS) system. Guided by forecasts calculated with the Lagrangian model, Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT), 64 tracer samples were collected onboard the Falcon approximately 5 and 25 h after the release, respectively, mostly with a time resolution of 1 min. Enhanced PMCP concentrations relative to ambient PMCP background values (mean: 6.62 fmol mol−1) were detected during three intersects of the fresh tracer plume (age 5 h), with a maximum value of 301.33 fmol mol−1. This indicates that the fresh tracer plume was successfully intercepted at the forecasted position. During the second flight, 25 h after the release, the center of tracer plume was not detected by the sampling system due to a faster advection of the plume than forecasted. The newly developed PERTRAS system has been successfully deployed for the first time. The instrumental set-up and comparisons between the measurements and HYSPLIT simulations are presented in this study.

scholarly journals BANDED VAULTS IN TURIN: TLS SURVEY, GEOMETRIC INTERPRETATION, DIGITAL RE-CONSTRUCTION, BETWEEN DESIGN AND CONSTRUCTION. PALAZZO CAPRIS DI CIGLIÈ

2021 ◽  
Vol XLVI-M-1-2021 ◽  
pp. 793-800
Author(s):  
M. Vitali ◽  
M. C. López González ◽  
G. Bertola ◽  
F. Natta
Keyword(s):  
Survey Data ◽  
Geometric Interpretation ◽  
Parametric Model ◽  
Parametric Modeling ◽  
Focus Attention ◽  
Survey Analysis ◽  
Digital Modeling ◽  
Set Up ◽  
Design And Construction

Abstract. This contribution intends to focus attention on the banded vault (‘a fascioni’) that characterizes the atrium of the Capris di Cigliè Palace in Turin, whose construction is dated around 1730 and is attributed to Gian Giacomo Plantery (1680–1756).The work of survey, analysis, interpretation and digital modeling has been organized in phases (detailed respectively in the next paragraphs) which have allowed us to: study the criteria of architectural-geometric composition at the base of the complex vaulted system that is the object of the present study and to relate them to the most usual operative practices of construction, in particular to the realization and arrangement of the centerings; organize the survey on the basis of the main treatise and manual sources, in order to choose the most appropriate working methods; analyze survey data and set up a parametric model of geometric interpretation; make a comparison between the survey data and the interpretive model.In particular, the phases of geometric reading and interpretation, parametric modeling and discussion of the results were structured with the aim of studying in detail the different arches that define the structure of the banded vault.

Investigation of Combustor-Turbine-Interaction in a Rotating Cooled Transonic High-Pressure Turbine Test Rig: Part 1 — Experimental Results

2019 ◽  
Author(s):  
Alexander Krumme ◽  
Clemens Buske ◽  
Johannes R. Bachner ◽  
Jerrit Dähnert ◽  
Marc Tegeler ◽  
...  
Keyword(s):  
Boundary Condition ◽  
High Pressure ◽  
Flow Field ◽  
Flow Structures ◽  
Test Rig ◽  
High Pressure Turbine ◽  
Set Up ◽  
German Aerospace ◽  
Interaction Research ◽  
Probe Measurements

Abstract Within the scope of European Commission FP7 project FACTOR, dedicated to combustor-turbine-interaction research, a clean-sheet design of a rotating turbine test rig featuring a non-reacting combustor simulator was created and built among the partners. German Aerospace Center DLR provided the operational facility NG-Turb to which the rig was adapted and was responsible for global rig integration and operation, also including aerodynamic probe measurements of the flow field. The rig and experimental set-up is described and post-processed results from probe traverses in several measurement planes are presented and discussed. Special attention is paid to the comparison and influence of two combustor-NGV clocking positions on the periodic turbine flow field, made possible by rig adaptation during the campaign. The strongly distorted and nonuniform turbine inlet flow created by the combustor simulator proved challenging for the probe measurements, but at the same time set a realistic boundary condition enabling the analysis of ‘CTI’ by flow structures migrating through the blade rows.

Superficial Discussion on New Framework of Static Equilibrium

2014 ◽  
Vol 670-671 ◽  
pp. 691-695
Author(s):  
Xiang Ming Zhang ◽  
Li Bao Zhu ◽  
An Wen Wang ◽  
Shao Hong Yang ◽  
Ming Yong Hu
Keyword(s):  
Long Range ◽  
Static Equilibrium ◽  
Equilibrium System ◽  
Force System ◽  
Basis Theorem ◽  
Force Systems ◽  
Set Up ◽  
Reasonable Description ◽  
New Framework

Statics is set up on the basis of 4 axioms of statics. Although these axioms are distillate and summarizing of the accumulated humankind's experience in long-range production and life, introduction of these axioms to statics seems a bit abrupt, especially the critical axiom "resultant of two forces" far fetched. This article was an attempt to present the embodying description of the effect of force and force system, based on the nature of effect of force and the equivalent and equilibrium of force systems. On this basis, theorem of two forces resultant and the theorem of two forces balance were proved, and the theorem of force systems equivalent was brought up. A new framework of static equilibrium system was built up to try to make a more perfect and more reasonable description for static equilibrium.

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