A key design parameter proposal for aerodynamically efficient subsonic blended wing body

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Seyhun Durmus
Keyword(s):  
Aspect Ratio ◽  
Design Parameter ◽  
Low Noise ◽  
Design Stage ◽  
Efficiency Coefficient ◽  
Content Type ◽  
Blended Wing Body ◽  
Wetted Area ◽  
Drag Ratio ◽  
Weight Data

Purpose Blended wing body (BWB) is a very advantageous design in terms of low fuel consumption, low emission and low noise levels. Because of these advantages, the BWB is a candidate to become the commercial passenger aircraft of the future by providing a paradigm shift in conventional designs. This paper aims to propose a key design parameter for wing sizing of subsonic BWB and a performance parameter for calculating the lift/drag ratio values of BWBs. Design/methodology/approach The parameter proposed in the study is based on the square/cube law, that is, the idea that the wetted area is proportional to the power of 2/3 of the weight. Data on the weight, wing area, wingspan, lift-to-drag (L/D) ratio for 19 BWB used in the analyzes were compiled from the published literature and a theoretical methodology was developed to estimate the maximum lift to drag ratio of BWBs. The accuracy of the proposed key design parameter was questioned by comparing the estimated L/Dmax values with the actual values. Findings In the current study, it is claimed that the wingspan/(take-off gross weight)(1/3) parameter provides an L/D efficiency coefficient regardless of aircraft size. The proposed key design parameter is useful both for small-scale BWB, that is unmanned aerial vehicles BWB and for large-scale BWB designs. Therefore, the b/Wg(1/3) parameter offers a dimensionless L/D efficiency coefficient for BWB designs of different scales. The wetted aspect ratio explains how low aspect ratio (AR)-BWB designs can compete with high AR-tube-and-wing designs. The key parameter is also useful for getting an idea of good or bad BWB with design and performance data published in the literature. As a result, reducing the blending area and designing a smaller central body are typical features of aerodynamically efficient BWB. Originality/value As the role of the square/cube law in the conceptual aircraft design stage has not been sufficiently studied in the literature, the application of this law to BWBs, a new generation of designs, makes the study original. Estimation of the wetted area ratio using only wingspan and gross weight data is an alternative and practical method for assessing the aerodynamic performance of the BWB. According to the model proposed in the current study, reducing the take-off gross weight of the BWBs using lighter building materials and designing with a larger wingspan (b) are the main recommendations for an aerodynamically efficient BWB.

scholarly journals Power Fan Design of Blended-Wing-Body Aircraft with Distributed Propulsion System

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Yuan Jia ◽  
Jinye Li ◽  
Jianghao Wu
Keyword(s):  
Boundary Layer ◽  
Internal Flow ◽  
Calculation Model ◽  
External Flow ◽  
Low Noise ◽  
Strongly Coupled ◽  
Distributed Propulsion ◽  
Blended Wing Body ◽  
Passenger Aircraft ◽  
Drag Ratio

A blended-wing-body aircraft has the advantages of high lift-to-drag ratio, low noise, and high economy compared with traditional aircraft. It is currently a solution with great potential to become a future civilian passenger aircraft. However, most airplanes with this layout use distributed power, and the power system is on the back of the fuselage, with embedded or back-supported engines. This type of design causes the boundary layer suction effect. The boundary layer ingestion (BLI) effect can fill the wake of the aircraft and improve the propulsion efficiency of the engine. However, it causes huge design difficulties, especially when the aircraft and the engine are strongly coupled. In this paper, an aircraft with a coupled engine configuration is studied. The internal and external flow fields are calculated through numerical simulation. A realistic calculation model is obtained through the coupling of boundary conditions. On the basis of the influence of the external flow on the internal flow under the coupled condition, the influence of the BLI effect on the aerodynamic performance of the fan is investigated.

Aerodynamic performance improvement of a canard control missile

2017 ◽  
Vol 89 (6) ◽  
pp. 871-878 ◽  
Author(s):  
M. Tahani ◽  
M. Masdari ◽  
M. Kazemi
Keyword(s):  
Aspect Ratio ◽  
Drag Coefficient ◽  
Cross Section ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Slender Body Theory ◽  
Content Type ◽  
Drag Ratio ◽  
Body Theory ◽  
Lift To Drag Ratio

Purpose This paper aims to analyze the influence of the changings in geometrical parameters on the aerodynamic performance of the control canard projectiles. Design/methodology/approach Because of the mentioned point, the range of projectiles increment has a considerable importance, and the design algorithm of a control canard projectile was first written. Then, were studied the effects of canard geometric parameters such as aspect ratio, taper ratio and deflectable nose on lift to drag coefficient ratio, static margin based on the slender body theory and cross section flow. Findings The code results show that aspect ratio increment, results in an increase in lift-to-drag ratio of the missile, but increase in canard taper ratio results in increasing of lift-to-drag ratio at 1° angle of attack, while during increasing the canard taper ratio up to 0.67 at 4° angle of attack, lift to drag first reaches to maximum and then decreases. Also, static margin decreases with canard taper ratio and aspect ratio increment. The developed results for this type of missile were compared with same experimental and computational fluid dynamic (CFD) results and appreciated agreement with other results at angles of attack between 0° and 6°. Practical implications To design a control canard missile, the effect of each geometric parameter of canard needs to be estimated. For this purpose, the suitable algorithm is used. In this paper, the effects of canard geometric parameters, such as aspect ratio, taper ratio and deflectable nose on lift-to-drag coefficient ratio and static margin, were studied with help of the slender body theory and cross-section flow. Originality/value The contribution of this paper is to predict the aerodynamic characteristics for the control canard missile. In this study, the effect of the design parameter on aerodynamic characteristics can be estimated, and the effect of geometrical characteristics has been analyzed with a suitable algorithm. Also, the best lift-to-drag coefficient for the NASA Tandem Control Missile at Mach 1.75 was selected at various angles of attack. The developed results for this type of missile were compared with same experimental and CFD results.

Investigation of sustainability of lubricated journal bearing under relevant design parameters

2018 ◽  
Vol 70 (4) ◽  
pp. 789-804 ◽  
Author(s):  
M.M. Shahin ◽  
Mohammad Asaduzzaman Chowdhury ◽  
Md. Arefin Kowser ◽  
Uttam Kumar Debnath ◽  
M.H. Monir
Keyword(s):  
Aspect Ratio ◽  
Elastic Strain ◽  
Journal Bearing ◽  
Design Parameters ◽  
Content Type ◽  
Computational Fluid Dynamics Cfd ◽  
Stress Formation ◽  
Bearing Design ◽  
The Stability ◽  
Bearing Friction

Purpose The purposes of the present study are to ensure higher sustainability of journal bearings under different applied loads and to observe bearing performances such as elastic strain, total deformation and stress formation. Design/methodology/approach A journal bearing test rig was used to determine the effect of the applied load on the bearing friction, film thickness, lubricant film pressure, etc. A steady-state analysis was performed to obtain the bearing performance. Findings An efficient aspect ratio (L/D) range was obtained to increase the durability or the stability of the bearing while the bearing is in the working condition by using SAE 5W-30 oil. The results from the study were compared with previous studies in which different types of oil and water, such as Newtonian fluid (NF), magnetorheological fluid (MRF) and nonmagnetorheological fluid (NMRF), were used as the lubricant. To ensure a preferable aspect ratio range (0.25-0.50), a computational fluid dynamics (CFD) analysis was conducted by ANSYS; the results show a lower elastic strain and deformation within the preferable aspect ratio (0.25-0.50) rather than a higher aspect ratio using the SAE 5W-30 oil. Originality/value It is expected that the findings of this study will contribute to the improvement of the bearing design and the bearing lubricating system.

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.

Appreciative inquiry's potential in program evaluation and research

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dana M. Griggs ◽  
Mindy Crain-Dorough
Keyword(s):  
Program Evaluation ◽  
Public Education ◽  
Research Study ◽  
Design Stage ◽  
Research Approach ◽  
Evaluation Tool ◽  
Content Type ◽  
Educational Partnership ◽  
Data Saturation ◽  
Applications Of Ai

PurposeThe purposes of this paper are to provide a description of AI and to document and compare two applications of AI, one in program evaluation and another in an applied research study.Design/methodology/approachFocus groups, interviews and observations were used to gather rich qualitative data which was used to detail Appreciative Inquiry's value in evaluation and research.FindingsAI aided the researcher in connecting with the participants and valuing what they shared. In both studies, the use of AI amassed information that answered the research questions, provided a rich description of the context and findings, and led to data saturation. The authors describe and compare experiences with two applications of AI: program evaluation and a research study. This paper contributes further understanding of the use of AI in public education institutions. The researchers also explore the efficacy of using AI in qualitative research and recommend its use for multiple purposes.Research limitations/implicationsLimitations occurred in the AI-Design Stage by using a positive viewpoint and because both program and partnership studied were new with limited data to use for designing a better future. So, the authors recommend a revisit of both studies through the same 4D Model.Practical implicationsThis manuscript shows that AI is useful for evaluation and research. It amplifies the participants' voices through favorite stories and successes. AI has many undiscovered uses.Social implicationsThrough the use of AI the authors can: improve theoretical perspectives; conduct research that yields more authentic data; enable participants to deeply reflect on their practice and feel empowered; and ultimately impact and improve the world.Originality/valueAI is presented as an evaluation tool for a high-school program and as a research approach identifying strengths and perceptions of an educational partnership. In both studies, AI crumbled the walls that are often erected by interviewees when expecting to justify or defend decisions and actions. This paper contributes further understanding of the use of AI in public education institutions.

A new jig-shape optimization method for the high aspect ratio wing

2018 ◽  
Vol 91 (1) ◽  
pp. 124-133
Author(s):  
Zhe Yuan ◽  
Shihui Huo ◽  
Jianting Ren
Keyword(s):  
Aspect Ratio ◽  
Shape Optimization ◽  
High Aspect Ratio ◽  
Optimization Design ◽  
Design Method ◽  
Aircraft Design ◽  
Optimization Method ◽  
Attack Angle ◽  
Structural Deformation ◽  
Content Type

Purpose Computational efficiency is always the major concern in aircraft design. The purpose of this research is to investigate an efficient jig-shape optimization design method. A new jig-shape optimization method is presented in the current study and its application on the high aspect ratio wing is discussed. Design/methodology/approach First, the effects of bending and torsion on aerodynamic distribution were discussed. The effect of bending deformation was equivalent to the change of attack angle through a new equivalent method. The equivalent attack angle showed a linear dependence on the quadratic function of bending. Then, a new jig-shape optimization method taking integrated structural deformation into account was proposed. The method was realized by four substeps: object decomposition, optimization design, inversion and evaluation. Findings After the new jig-shape optimization design, both aerodynamic distribution and structural configuration have satisfactory results. Meanwhile, the method takes both bending and torsion deformation into account. Practical implications The new jig-shape optimization method can be well used for the high aspect ratio wing. Originality/value The new method is an innovation based on the traditional single parameter design method. It is suitable for engineering application.

Schedule and cost overrun analysis for R&D projects using ANP and system dynamics

2017 ◽  
Vol 34 (9) ◽  
pp. 1551-1567 ◽  
Author(s):  
Sandeep Kumar ◽  
J.J. Thakkar
Keyword(s):  
System Dynamics ◽  
Risk Mitigation ◽  
Analytic Network Process ◽  
Raw Material ◽  
Design Stage ◽  
Economic Factors ◽  
Cost Overrun ◽  
Individual Factor ◽  
Content Type ◽  
Network Process

Purpose Schedule and cost overrun analysis for a typical research & development (R&D) project is necessary to identify and mitigate the non-feasible alternatives at the design stage. Typically, this should include an analysis of technological and economic factors of R&D project. This paper aims to discuss these issues. Design/methodology/approach This research proposes an integrated analytic network process (ANP) and reusable system dynamics (SD) model for a quick and strategically consistent decision making. The technological and economic factors of R&D project were first identified and compiled through a systematic literature review. An ANP model was first developed for calculating Risk Priority Index (RPI) for set of technological and economic factors. The computed RPI are considered as an input to SD models. Two SD models (technological and economic) are developed to undertake a detailed investigation on effect of individual factor on schedule and cost overrun. The approach is exemplified for a case of government R&D project in India. Findings ANP identifies “Testing & qualification facility” and “Raw material availability” as the highest RPI factors. A detailed sensitivity analysis of SD models suggests that technological factors such as “Design Changes,” “Hidden Activities,” and “Lack of Expertise” and economic factors such as “Project delays,” “Unexpected incidents” and “Conflicts” have the highest influence on schedule and cost overrun. Practical implications The outcomes of this research can help managers to estimate the severity of various technological and economic factors on cost and schedule overrun and develop an adequate risk mitigation contingency plan. Originality/value In case of R&D projects where systems are being developed for the first time, changes are inevitable, and hence schedule and cost management plays a very important role in its success. This paper proposes an integrated reusable approach of ANP and SD for analyzing the influence of technological and economic factors on schedule and cost overrun of R&D project.

Polish perceptions on changing the world with sustainable entrepreneurship

2021 ◽  
Vol 37 (4) ◽  
pp. 19-21
Keyword(s):  
Value Creation ◽  
Design Methodology ◽  
Business Models ◽  
Design Stage ◽  
Model Design ◽  
Content Type ◽  
Coffee Waste ◽  
The World ◽  
Pertinent Information ◽  
Practical Implications

Purpose This paper aims to review the latest management developments across the globe and pinpoint practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings This research paper highlights how circular economy business models focus on the regenerative value creation inherent in reusing resources and waste. Circular startup transformations see founders moving out of sustainability-focused mindsets and into taking specific action to construct innovative circular business models. The purpose-led founders combined environmental and economic goals to produce scalable engines capable of inspiring and educating customers and larger companies on the beauty of reusing waste. Solving universal problems at their business model design stage allowed the Polish startups – for example, EcoBean who make renewable energy coffee briquettes from coffee waste – to offer value to international customers. Originality/value The briefing saves busy executives, strategists and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.

Cost and environmental performance of forced air and hot water heating systems in post-Soviet countries

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Begmyrat Kulmedov ◽  
Serdar Durdyev
Keyword(s):  
Natural Gas ◽  
Environmental Performance ◽  
Residential Buildings ◽  
Electricity Consumption ◽  
Cost Effective ◽  
Hot Water ◽  
Design Stage ◽  
High Price ◽  
Content Type ◽  
Heating Systems

PurposeThe aim of the present study is to assess the selected heating systems (furnace and boiler) commonly used in the dwellings of seven post-USSR (the Union of Soviet Socialist Republics) countries. The systems were assessed in terms of their cost and environmental performance, with natural gas and electricity used as the main source of energy.Design/methodology/approachThe cost-effectiveness and environmental performance of the selected heating systems that have been commonly used in the selected post-USSR countries was assessed. Current energy (natural gas and electricity) prices that are applied in those countries were used.FindingsResults show that the furnace is the cheapest option, while natural gas is the cheapest source of energy, despite its high price in Tajikistan and Kyrgyzstan. Both heating systems could be considered eco-friendly options, although their efficiencies need to be considered at the design stage. Turkmenistan, Uzbekistan and Kazakhstan, which are the top natural gas producers, offer natural gas for the selected heating systems as both cost-effective and eco-friendly options.Practical implicationsA considerable reduction in electricity consumption and less harm to our environment can be achieved through the systems used in residential buildings in the region.Originality/valueThe outcomes of the present study offer value (in terms of cost-effective and eco-friendly options) for the end-users in the region.

Experimental analysis of fluid-structure interaction in flexible wings at low Reynolds number flows

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mustafa Serdar Genç ◽  
Hacımurat Demir ◽  
Mustafa Özden ◽  
Tuna Murat Bodur
Keyword(s):  
Reynolds Number ◽  
Aspect Ratio ◽  
Fluid Structure Interaction ◽  
Leading Edge ◽  
Flexible Wings ◽  
Flexible Membrane ◽  
Fluid Structure ◽  
Content Type ◽  
Structure Interaction ◽  
Membrane Deformations

Purpose The purpose of this exhaustive experimental study is to investigate the fluid-structure interaction in the flexible membrane wings over a range of angles of attack for various Reynolds numbers. Design/methodology/approach In this paper, an experimental study on fluid-structure interaction of flexible membrane wings was presented at Reynolds numbers of 2.5 × 104, 5 × 104 and 7.5 × 104. In the experimental studies, flow visualization, velocity and deformation measurements for flexible membrane wings were performed by the smoke-wire technique, multichannel constant temperature anemometer and digital image correlation system, respectively. All experimental results were combined and fluid-structure interaction was discussed. Findings In the flexible wings with the higher aspect ratio, higher vibration modes were noticed because the leading-edge separation was dominant at lower angles of attack. As both Reynolds number and the aspect ratio increased, the maximum membrane deformations increased and the vibrations became visible, secondary vibration modes were observed with growing the leading-edge vortices at moderate angles of attack. Moreover, in the graphs of the spectral analysis of the membrane displacement and the velocity; the dominant frequencies coincided because of the interaction of the flow over the wings and the membrane deformations. Originality/value Unlike available literature, obtained results were presented comparatively using the sketches of the smoke-wire photographs with deformation measurement or turbulence statistics from the velocity measurements. In this study, fluid-structure interaction and leading-edge vortices of membrane wings were investigated in detail with increasing both Reynolds number and the aspect ratio.

Sign in / Sign up

Export Citation Format

Share Document