scholarly journals Structural design process and subsequent flight mechanical evaluation in preliminary aircraft design: demonstrated on passenger ride comfort assessment

2021 ◽  
Author(s):  
Vikram Krishnamurthy ◽  
Vega Handojo
Keyword(s):  
Design Process ◽  
Structural Design ◽  
Assessment Tool ◽  
Ride Comfort ◽  
Aircraft Design ◽  
Flight Mechanics ◽  
Design Stage ◽  
Preliminary Aircraft Design ◽  
The Impact ◽  
Tools And Methods

AbstractNew fuel-efficient aircraft designs have high aspect ratio wings. Consequently, those aircraft are more flexible. Additionally, load alleviation functions are implemented to reduce the structural loads, which results in further reductions of the structural stiffness. At the same time, the structural design impacts other disciplines in preliminary aircraft design, especially flight mechanics. For example, it is important to know how at that design stage such flexible aircraft with load alleviation affect passenger ride comfort in turbulent flight. For an efficient design process, it is essential to answer such questions with accurate multi-disciplinary tools and methods as early as possible to minimize development risk and avoid costly and time-consuming redesign loops. Current available tools and methods are not accurate enough for this task. To address this issue, the DLR MONA based design and the TUB flight mechanical assessment tool MITRA are linked to investigate the impact of the structural design on specific flight mechanical assessments such as passenger ride comfort. This is particularly interesting since the implemented load alleviation functions are designed to reduce loads, and not explicitly to improve passenger ride comfort. By conducting this assessment for a particular aircraft configuration, more insight into passenger ride comfort and the key contributors can be gained during preliminary design. This paper describes the combined toolchain and its application on a generic long-range reference aircraft to investigate the effects of load alleviation functions on passenger ride comfort and discusses the results.

scholarly journals Effect of Levels of Fidelity on Steady Aerodynamic and Static Aeroelastic Computations

Aerospace ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 42 ◽  
Author(s):  
Adrien Crovato ◽  
Hugo S. Almeida ◽  
Gareth Vio ◽  
Gustavo H. Silva ◽  
Alex P. Prado ◽  
...  
Keyword(s):  
Linear Method ◽  
Computational Cost ◽  
Aircraft Design ◽  
Design Stage ◽  
Full Potential ◽  
Linear Potential ◽  
Nonlinear Method ◽  
Transonic Flows ◽  
Preliminary Aircraft Design ◽  
The Impact

Static aeroelastic deformations are nowadays considered as early as in the preliminary aircraft design stage, where low-fidelity linear aerodynamic modeling is favored because of its low computational cost. However, transonic flows are essentially nonlinear. The present work aims at assessing the impact of the aerodynamic level of fidelity used in preliminary aircraft design. Several fluid models ranging from the linear potential to the Navier–Stokes formulations were used to solve transonic flows for steady rigid aerodynamic and static aeroelastic computations on two benchmark wings: the Onera M6 and a generic airliner wing. The lift and moment loading distributions, as well as the bending and twisting deformations predicted by the different models, were examined, along with the computational costs of the various solutions. The results illustrate that a nonlinear method is required to reliably perform steady aerodynamic computations on rigid wings. For such computations, the best tradeoff between accuracy and computational cost is achieved by the full potential formulation. On the other hand, static aeroelastic computations are usually performed on optimized wings for which transonic effects are weak. In such cases, linear potential methods were found to yield sufficiently reliable results. If the linear method of choice is the doublet lattice approach, it must be corrected using a nonlinear solution.

An investigation of the mass-market fashion design process

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Prabod Dharshana Munasinghe ◽  
D.G.K. Dissanayake ◽  
Angela Druckman
Keyword(s):  
Design Process ◽  
Market Design ◽  
High Volume ◽  
Design Stage ◽  
Fashion Design ◽  
Structured Interviews ◽  
Mass Market ◽  
Content Type ◽  
Responsible Consumption ◽  
The Impact

Purpose The process of fashion design varies between market segments, yet these variations have not yet been properly explored. This study aims to examine the fashion design process as practised at the mass-market level, as this is the most vibrant and the largest market segment in terms of production volumes and sales. Design/methodology/approach It is observed that 15 semi-structured interviews were conducted with mass-market fashion designers. Key activities of the mass-market design process were identified and a comparative analysis was conducted with the general design process. Findings The mass-market design process is found to prioritise profits rather than aesthetic aspects, with the buyer exercising more power than the designer. This hinders creativity, which, in turn, may impede a move towards more environmentally benign designs. Originality/value The clothing industry is responsible for high environmental impacts and many of these impacts arise through decisions made in the design stage. In particular, the mass-market for clothing because of its high volume of sales and fast throughput, accounts for a great deal of the impact. However, little is understood about the design process that is practised in the mass-fashion market. This paper fills the gap by developing a framework that describes the mass-market design process. Understanding the design process will enable progress to be made towards achieving the United Nations Sustainable Development Goal 12: Responsible Consumption and Production.

Handling and Primary Ride Comfort Development in Early Design Stage by Means of 1D Modeling Approach and Multi Attribute Optimization Process

2011 ◽  
Author(s):  
Stefano Alneri ◽  
Paolo di Carlo ◽  
Alessandro Toso ◽  
Stijn Donders
Keyword(s):  
Performance Metrics ◽  
Ride Comfort ◽  
Experimental Tests ◽  
Complex Model ◽  
Design Stage ◽  
Time Saving ◽  
Vehicle Performance ◽  
Early Design Stage ◽  
Automotive Market ◽  
The Impact

Today the automotive market is ever more competitive and vehicles must satisfy the requirements of the customers in all respects: handling, comfort, acoustics, fuel economy, etc. Therefore OEMs have to launch innovative products in a short development timeline: the time to market (TTM) of new vehicles has continually decreased and nowadays the developing process of a new car is completed in less years than in the past. This scenario emphasizes the role of CAE in the vehicle design engineering design and the necessity of exploiting its potentialities, in order to shorten the TTM and to reduce the impact of experimental tests on it. In this context a step-by-step approach with multi-physics 1D environment such as LMS Imagine. Lab AMESim is proposed in order to monitor vehicle performances in all the design stages, thanks to the employment of models with increasing complexity. In addition the ultimate step can be employed for performing a multi attribute optimization on vehicle performance metrics in order to find the best attributes balancing and to pass the preliminary recommendations to the design with a considerable time-saving respect to 3D MBS models. This paper briefly describes the process for building 1D models with LMS Imagine.Lab AMESim and moreover it shows the definition of a multi attribute optimization algorithm in terms of handling performances with the most complex model.

Integration of Crashworthiness Aspects into Preliminary Aircraft Design

2014 ◽  
Vol 598 ◽  
pp. 146-150 ◽  
Author(s):  
Dominik B. Schwinn
Keyword(s):  
Design Process ◽  
Aircraft Design ◽  
Analysis Tool ◽  
Preliminary Design ◽  
Design Phase ◽  
Crash Analysis ◽  
Early Design ◽  
Preliminary Aircraft Design ◽  
Early Design Stages ◽  
Certification Requirement

Crashworthiness proof is a certification requirement by aviation authorities for new aircraft types. The objective of static design is a sufficiently stiff and strong structure to carry bending and torsion during flight and ground maneuvers. High stiffness, however, is critical for good crashworthiness behavior. Therefore, crashworthiness investigations should be included at early design stages of the overall aircraft design process. This paper introduces the crash analysis tool AC-CRASH and shows an approach of integrating it into the preliminary design phase.

scholarly journals Influence of a Vibration Isolation System on Planar Dynamics of a Motorcycle

2020 ◽  
Vol 25 (1) ◽  
pp. 96-103
Author(s):  
Sudhir Kaul
Keyword(s):  
Simple Model ◽  
Design Process ◽  
Dynamic Characteristics ◽  
Vibration Isolation ◽  
Ride Comfort ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Natural Modes ◽  
The Impact ◽  
Unsprung Mass

This paper examines a model to investigate the impact of a vibration isolation system on the planar (in-plane) dynamics of a motorcycle. While it is not very common, a vibration isolation system is used in some motorcycles to mitigate vibrations resulting from the shaking forces of the engine. For such layouts, the powertrain is assembled to the frame through the vibration isolation system that typically consists of two to four isolators. It is critical to comprehend the influence of the isolation system on the overall dynamic characteristics of the motorcycle due to the coupled dynamics of the rear suspension, the isolation system, and the rear unsprung mass. The influence of a vibration isolation system on the in-plane dynamics is analysed by using a relatively simple model that has been developed in this study. This model has been used to evaluate the influence of the isolation system on natural modes, transmissibility, and ride comfort. Results indicate that the use of a vibration isolation system couples the rear unsprung hop to the pitch motion of the powertrain with a slight increase in the corresponding natural frequency. Results indicate that the use of a vibration isolation system directly affects handling of the motorcycle. Furthermore, results indicate that the pitch of the sprung mass and the hop of the rear unsprung mass are particularly influenced by the vibration isolation system. The model presented in this paper could be useful in the early stages of the design process to compare the rigidly mounted powertrain to different layouts of the vibration isolation system.

Contrail avoidance in the aircraft design process

2008 ◽  
Vol 112 (1138) ◽  
pp. 733-737 ◽  
Author(s):  
F. Noppel ◽  
R. Singh
Keyword(s):  
Design Process ◽  
Radiative Forcing ◽  
Meteorological Data ◽  
Aircraft Design ◽  
Air Traffic ◽  
Industrial Sectors ◽  
Fuel Burn ◽  
Aircraft Type ◽  
The Impact ◽  
Traffic Pollutants

AbstractAs aviation is one of the fastest growing industrial sectors world wide, air-traffic emissions are projected to increase their stake in the contribution to global warming. According to studies, both carbon dioxide and contrails are the principal air-traffic pollutants, whereas the impact from contrails in terms of radiative forcing is possibly larger than that of all other air-traffic pollutants combined. New regulations with the objective of mitigating contrail occurrences might cause a change in the design requirements of aircraft. In light of this, a method considering contrail formation during the aircraft design process is presented in this paper. Aircraft performance and optimisation is carried out with NASA’s flight optimisation system. Combining historical meteorological data with air-traffic data enables an assessment regarding contrail formation. As an example, a particular aircraft type in terms of range, speed and payload is optimised for minimum block fuel consumption considering different altitudes. The change in contrail formation in terms of contrail-km formed is calculated. The results suggest that if aircraft of the considered class were designed for higher altitudes, contrail occurrences would diminish slightly at a non-negligible fuel burn penalty.

Applied parametrized and automated airframe modeling methods in the preliminary design phase

2015 ◽  
Vol 06 (04) ◽  
pp. 1550037 ◽  
Author(s):  
Dominik B. Schwinn
Keyword(s):  
Design Process ◽  
Aircraft Design ◽  
Design Stage ◽  
Model Generation ◽  
Preliminary Design ◽  
Generation Process ◽  
Design Phase ◽  
Worst Case ◽  
Detailed Design ◽  
Preliminary Design Stage

The design process of new air- and rotorcraft is commonly separated into three different consecutive phases. In the conceptual design phase, the viability of different designs is investigated with respect to customer requirements and/or the market situation. It usually ends with the identification of a basic aircraft lay-out. In the subsequent preliminary design stage the various disciplines are introduced, thus redefining the design process as a multidisciplinary optimization (MDO) task. The objective of this design stage is to enhance the initial aircraft configuration by establishing an advanced design comprising a loft provided with primary structure. This updated aircraft configuration represents a global optimum solution for the specified requirements which will then be optimized on a local level in the concluding detailed design phase with particular regard to manufacturing aspects. The investigations in the preliminary design phase comprise the generation of numerous similar but still different analytical and finite element (FE) models. Even though computational power is constantly increasing the model generation process is still a time-consuming task. Moreover, it is also a potential source of errors which — in the worst case — may lead to time- and cost-intensive redesign activities during the detailed design. As the preliminary design stage, therefore, is of particular importance during the overall design process the model generation process benefits from parametric models and automated process chains. The presented paper overviews the tools used for the automated generation of FE models developed and used at the Institute of Structures and Design (BT) of the German Aerospace Center (DLR) for the subsequent use in numerical simulations. Furthermore, basic requirements for the effective use of parametrization and automation like a common data format and infrastructure will be introduced. Exemplary models and applications will be presented to illustrate the positive impact on efficiency in aircraft design. Concluding, future development steps and possible applications will be discussed.

The Impact of Decisions Made in Various Architectural Design Stages on Life Cycle Assessment Results

2016 ◽  
Vol 861 ◽  
pp. 593-600 ◽  
Author(s):  
Benedek Kiss ◽  
Zsuzsa Szalay
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Design Process ◽  
Architectural Design ◽  
Environmental Indicators ◽  
Design Stage ◽  
Single Family ◽  
The Impact ◽  
Made In

Life Cycle Assessment (LCA) is an advantageous tool for the analysis of the overall environmental effects of a building. Most of the decisions that influence the final result of an LCA are made during the design process of the building. Therefore, LCA in early design stages is crucial, because the changes in this period of design are cheaper and more effective. However, there are many other aspects that influence the design of a building. During the design process a high number of variables have to be defined, and in each design stage a specific number of variables have to be fixed depending on various engineering considerations. In this paper we investigate the effect of decisions made in each design stage on LCA results. Within this paper the available possibilities are compared with the variant that was actually selected in each stage, and it is evaluated how environmental indicators evolve during the whole design process. The approach is demonstrated on a case study of a realized single family house.

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