The simulation of single wraparound fin on a semi-cylindrical missile body

2020 ◽  
Vol 92 (3) ◽  
pp. 418-427 ◽  
Author(s):  
Nayhel Sharma ◽  
Rakesh Kumar

Purpose The purpose of this paper is to establish a freestream computational fluid dynamics (CFD) model of a three-dimensional non-spinning semi-cylindrical missile model with a single wrap around fin in Mach 2.70-3.00M range and 0° angle of attack, and ultimately establishing itself for future research study. Design/methodology/approach In this study, the behaviour of flow around the fin was investigated using a κ-ϵ turbulence model of second-order of discretization. This was done using a highly structured mesh. Additionally, an inviscid CFD simulation involving the same boundary conditions have also been carried out for comparison. Findings The obtained values of aerodynamic coefficients and pressure contours visualizations are compared against their experimental and computational counterparts. A typical missile aerodynamic characteristic trend can be seen in the current CFD. Practical implications The predicted values of the aerodynamic coefficients of this single fin model have also been compared to those of the full missile body comprising of four fins from the previous research studies, and a similar aerodynamic trend can be seen. Originality/value This study explores the possibility of the use of turbulence modelling in a single fin model of a missile and provides a basic computational model for further understanding the flow behaviour near the fin.

2019 ◽  
Vol 91 (4) ◽  
pp. 620-633 ◽  
Author(s):  
Corrado Groth ◽  
Emiliano Costa ◽  
Marco Evangelos Biancolini

Purpose Numerical simulation of icing has become a standard. Once the iced shape is known, however, the analyst needs to update the computational fluid dynamics (CFD) grid. This paper aims to propose a method to update the numerical mesh with ice profiles. Design/methodology/approach The present paper concerns a novel and fast radial basis functions (RBF) mesh morphing technique to efficiently and accurately perform ice accretion simulations on industrial models in the aviation sector. This method can be linked to CFD analyses to dynamically reproduce the ice growth. Findings To verify the consistency of the proposed approach, one of the most challenging ice profile selected in the LEWICE manual was replicated and simulated through CFD. To showcase the effectiveness of this technique, predefined ice profiles were automatically applied on two-dimensional (2D) and three-dimensional (3D) cases using both commercial and open-source CFD solvers. Practical implications If ice accreted shapes are available, the meshless characteristic of the proposed approach enables its coupling with the CFD solvers currently supported by the RBF4AERO platform including OpenFOAM, SU2 and ANSYS Fluent. The advantages provided by the use of RBF are the high performance and reliability, due to the fast application of mesh smoothing and the accuracy in controlling surface mesh nodes. Originality/value As far as authors’ knowledge is concerned, this is the first time in scientific literature that RBF are proposed to handle icing simulations. Due to the meshless characteristic of the RBF mesh morphing, the proposed approach is cross solver and can be used for both 2D and 3D geometries.


2019 ◽  
Vol 25 (3) ◽  
pp. 378-396 ◽  
Author(s):  
Arian Razmi-Farooji ◽  
Hanna Kropsu-Vehkaperä ◽  
Janne Härkönen ◽  
Harri Haapasalo

Purpose The purpose of this paper is twofold: first, to understand data management challenges in e-maintenance systems from a holistically viewpoint through summarizing the earlier scattered research in the field, and second, to present a conceptual approach for addressing these challenges in practice. Design/methodology/approach The study is realized as a combination of a literature review and by the means of analyzing the practices on an industry leader in manufacturing and maintenance services. Findings This research provides a general understanding over data management challenges in e-maintenance and summarizes their associated proposed solutions. In addition, this paper lists and exemplifies different types and sources of data which can be collected in e-maintenance, across different organizational levels. Analyzing the data management practices of an e-maintenance industry leader provides a conceptual approach to address identified challenges in practice. Research limitations/implications Since this paper is based on studying the practices of a single company, it might be limited to generalize the results. Future research topics can focus on each of mentioned data management challenges and also validate the applicability of presented model in other companies and industries. Practical implications Understanding the e-maintenance-related challenges helps maintenance managers and other involved stakeholders in e-maintenance systems to better solve the challenges. Originality/value The so-far literature on e-maintenance has been studied with narrow focus to data and data management in e-maintenance appears as one of the less studied topics in the literature. This research paper contributes to e-maintenance by highlighting the deficiencies of the discussion surrounding the perspectives of data management in e-maintenance by studying all common data management challenges and listing different types of data which need to be acquired in e-maintenance systems.


2019 ◽  
Vol 9 (3) ◽  
pp. 319-328
Author(s):  
Ian Pepper ◽  
Ruth McGrath

Purpose The purpose of this paper is to evaluate the impact of an employability module, the College of Policing Certificate in Knowledge of Policing (CKP), on students’ career aspirations, their confidence and wish to join the police along with the appropriateness of the module. This will inform the implementation of employability as part of the College of Policing-managed Police Education Qualifications Framework (PEQF). Design/methodology/approach A three-year longitudinal research study used mixed methods across four points in time to evaluate the impact on students studying the employability module. Findings The research suggests that the employability-focussed CKP was useful as an introduction to policing, it developed interest in the police and enhanced the confidence of learners applying to join. Lessons learnt from the CKP should be considered during the implementation of the PEQF. Research limitations/implications The ability to generalise findings across different groups is limited as other influences may impact on a learner’s confidence and employability. However, the implications for the PEQF curriculum are worthy of consideration. Practical implications As the police service moves towards standardised higher educational provision and evolution of policing as a profession, lessons can be learnt from the CKP with regards to the future employability of graduates. Originality/value Enhancing the employability evidence base, focussing on policing, the research identified aspects which may impact on graduates completing a degree mapped to the PEQF. The research is therefore of value to higher education and the professional body for policing.


Author(s):  
Marcin Lefik ◽  
Krzysztof Komeza ◽  
Ewa Napieralska-Juszczak ◽  
Daniel Roger ◽  
Piotr Andrzej Napieralski

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program including effect of rotation and the resulting eddy current losses. To analyse the thermal phenomenon, the 3D coupled thermal-fluid (CFD) model is used. Findings The presented results show clearly that laminated construction is much better from a point of view of efficiency and temperature. However, solid construction can be interesting for high speed machines due to their mechanical robustness. Research limitations/implications The main problem, despite the use of parallel calculations, is the long calculation time. Practical implications The obtained simulation and experimental results show the possibility of building a machine operating at a much higher ambient temperature than it was previously produced for example in the vicinity of the aircraft turbines. Originality/value The paper presents the application of fully three-dimensional coupled electromagnetic and thermal analysis of new machine constructions designed for elevated temperature.


2015 ◽  
Vol 35 (3) ◽  
pp. 269-280 ◽  
Author(s):  
Hu Qiao ◽  
Rong Mo ◽  
Ying Xiang

Purpose – The purpose of this paper is to establish an adaptive assembly, to realize the adaptive changing of the models and to improve the flexibility and reliability of assembly change. For a three-dimensional (3D) computer-aided design (CAD) assembly in a changing process, there are two practical problems. One is delivering parameters’ information not smoothly. The other one is to easily destroy an assembly structure. Design/methodology/approach – The paper establishes associated parameters design structure matrix of related parts, and predicts possible propagation paths of the parameters. Based on the predicted path, structured storage is made for the affected parameters, tolerance range and the calculation relations. The study combines structured path information and all constrained assemblies to build the adaptive assembly, proposes an adaptive change algorithm for assembly changing and discusses the extendibility of the adaptive assembly. Findings – The approach would improve the flexibility and reliability of assembly change and be applied to different CAD platform. Practical implications – The examples illustrate the construction and adaptive behavior of the assembly and verify the feasibility and reasonability of the adaptive assembly in practical application. Originality/value – The adaptive assembly model proposed in the paper is an original method to assembly change. And compared with other methods, good results have been obtained.


2015 ◽  
Vol 36 (2) ◽  
pp. 216-235 ◽  
Author(s):  
Carlos Gradín ◽  
Olga Cantó ◽  
Coral del Río

Purpose – The purpose of this paper is to analyze the different dynamic characteristics of unemployment in a selected group of European Union countries during the current Great Recession, which had unequal consequences on employment depending on the country considered. Design/methodology/approach – The paper follows Shorrocks’s proposal of a duration-sensitive measure of unemployment, and uses cross-sectional data reported by Eurostat coming from European Labour Force Surveys. Findings – The results add some evidence on the relevance of incorporating spells’ duration in measuring unemployment, finding remarkable differences in unemployment patterns in time among European countries. Research limitations/implications – In this paper unemployment is analyzed for all the labor force. Future research should investigate patterns across specific groups such as young people, women, immigrants or the low skilled. Practical implications – It is generally accepted that the negative impact of unemployment on individual welfare can be very different depending on its duration. However, conventional statistics on unemployment do not adequately capture to what extent the recession is not only increasing the incidence of unemployment but also its severity in terms of duration in time of ongoing unemployment spells. The paper shows an easy and practical way to do it in order to improve the understanding of the unemployment phenomenon, using information usually reported by statistical offices. Originality/value – First, the paper provides a tool for dynamic analysis of unemployment based on reported cross-sectional data. Second, the paper demonstrates the empirical relevance of considering spells’ duration when assessing differences in unemployment across countries or in unemployment trends. This is usually neglected or only partially addressed by most conventional measures of unemployment.


2014 ◽  
Vol 5 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Sean Upton-McLaughlin

Purpose – The purpose of this paper was to explore the Chinese concept of suzhi and how it relates to behavioral standards within mainland Chinese society and the workplace. The article provides a general discussion of suzhi and its inherent elements to act as a foundation for the education of expatriate managers and executives and for future research by Chinese human resource management (HRM) scholars. Design/methodology/approach – This paper draws on the author's first-hand experience and observations from five years of living and working abroad in mainland China with Chinese companies and executives. Findings – The concept of suzhi in China is a reflection of multiple behavioral standards throughout China. And while suzhi's roots are in ancient Chinese culture and Confucianism, it is also subject to influence and change. Practical implications – The paper may serve as a foundation both for expatriate managers seeking to improve HRM practices in foreign companies in China and future scholars who wish to conduct further research on suzhi and Chinese behavioral standards as they can be applied to the workplace. Originality/value – This is an attempt to enlighten expatriate managers and executives in China on the concept of suzhi and its implication for HRM in China.


2017 ◽  
Vol 23 (3) ◽  
pp. 721-734 ◽  
Author(s):  
Matthias Murawski ◽  
Markus Bick

Purpose Considering working in the digital age, questions on the consequences for the individual workers are, so far, often neglected. The purpose of this paper is to deal with the question of whether the digital competences of the workforce is a research topic. The authors argue for the thesis that it is indeed a research topic. Design/methodology/approach In addition to a literature analysis of the top IS, HR, and learning publications, non-scientific sources, as well as the opinions of the authors, are included. The authors’ thesis is challenged through a debate of corresponding pros and cons. Findings The definition of digital competences lacks scientific depth. Focussing on the workforce is valid, as a “lifelong” perspective is not mandatory for research. Digital competence research is a multidisciplinary task to which the IS field can make a valuable contribution. Research limitations/implications Although relevant references are included, some aspects are mainly driven by the opinions of the authors. The theoretical implications encompass a call for a scientific definition of digital competences. Furthermore, scholars should focus on the competences of the workforce, including occupations, roles, or industries. The authors conclude by providing a first proposal of a research agenda. Practical implications The practical implications include the alignment of multiple stakeholders for the design of “digital” curricula and the integration by HR departments of the construct of digital competences, e.g. for compensation matters and job requirements. Originality/value This paper is one of very few contributions in the area of the digital competences of the workforce, and it presents a starting point for future research activities.


Author(s):  
Catalin Ratiu ◽  
Beverlee B. Anderson

Purpose – There are many different conceptualizations to sustainable development and these different approaches may have led to confusion amongst the public. The purpose of this paper is to explore the identities of the term and how the confused identity may be leading to problems for sustainable development efforts. Design/methodology/approach – The design is exploratory, using both secondary and primary data to understand the different sustainable development concepts. Findings – There is no consistent understanding or use of the term “sustainable development” among various groups. Research limitations/implications – Future research should include a larger sample that is more representative of people from different backgrounds and geographical areas. Practical implications – The public is generally willing to support only projects that it understands. Without a clear understanding of sustainable development, the public will be less inclined to support these efforts. Originality/value – This study examines the perceptions and understandings of the term by the general public representing different generations.


2018 ◽  
Vol 24 (1/2) ◽  
pp. 84-105 ◽  
Author(s):  
Daniel Marasquini Stipp ◽  
Márcio Lopes Pimenta ◽  
Daniel Jugend

Purpose The aim of this paper is to characterize how innovation may happen through cross-functional teams (CFT) in an organization of the public sector. Design/methodology/approach A case study helped to characterize several behavior patterns, team structures and respective links with generating innovation in internal processes and public answering contexts. Findings The results highlight that formal-temporary teams present a higher capacity to generate incremental innovation in products, whereas permanent-informal teams have a higher capacity to generate innovation in the internal processes and public answering contexts. Research limitations/implications The limitations of this research relate to the fact that this is a single case study, and although it is an important case to examine innovation and CFTs, by its very nature, it is not possible to extend and generalize the obtained data to other organizations. The evaluation of its propositions was merely qualitative, and future research is needed to validate its characteristics. Practical implications Several settings of CFTs are presented, as well as their ability to generate different types of innovation, such as the computerization of documents, petitions and papers, which decreases the time to answer the taxpayer. Moreover, CFTs can help to create products, such as computer programs that can be used not only locally but also in several public organizations related to tax management. Originality/value The field research provides the perceptions of the respondents regarding CFT characteristics that can lead to specific types of innovation, as well as the types of products or services that can be generated by these processes.


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