Influence of oil nozzle structure parameters on oil injection direction

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yanzhong Wang ◽  
Guanhua Song ◽  
Wentao Niu ◽  
Yaping Zhang

Purpose The purpose of this paper is to provide an analytical method of jet flow injection direction and to determine the influence of oil nozzle structure parameters on oil injection direction, thus providing the design method of oil nozzle structure parameters. Design/methodology/approach A model of oil injection loss is established to analyze the influence of oil nozzle structure parameters on oil injection direction. The computational fluid dynamics method is used to simulate the process of the deviation of jet flow injection direction. The deviation of jet flow injection direction with different oil nozzle structure parameters is calculated and their variations are obtained. Moreover, the deviation of jet flow injection direction with different oil nozzle structure parameters is tested to verify the analysis results. Findings Results indicate that radial velocity caused the deflection of the oil injection direction. The deviation of jet flow increased as the nozzle slenderness ratio decreased. The design method of the nozzle slenderness ratio (greater than five) is proposed to avoid the deviation of injection direction, and it is necessary to consider the matching between the nozzle slenderness ratio and pipeline pressure. The computational results coincide well with the experimental results. Originality/value The research presented here analyzed the influence of oil nozzle structure parameters on oil injection direction via a numerical analysis method. It also leads to a design reference guideline that could be used in jet lubrication, thus controlling the direction of the injection jet accurately.

2019 ◽  
Vol 37 (1) ◽  
pp. 345-367
Author(s):  
Hui Lü ◽  
Kun Yang ◽  
Wen-bin Shangguan ◽  
Hui Yin ◽  
DJ Yu

Purpose The purpose of this paper is to propose a unified optimization design method and apply it to handle the brake squeal instability involving various uncertainties in a unified framework. Design/methodology/approach Fuzzy random variables are taken as equivalent variables of conventional uncertain variables, and a unified response analysis method is first derived based on level-cut technique, Taylor expansion and central difference scheme. Next, a unified reliability analysis method is developed by integrating the unified response analysis and fuzzy possibility theory. Finally, based on the unified reliability analysis method, a unified reliability-based optimization model is established, which is capable of optimizing uncertain responses in a unified way for different uncertainty cases. Findings The proposed method is extended to perform squeal instability analysis and optimization involving various uncertainties. Numerical examples under eight uncertainty cases are provided and the results demonstrate the effectiveness of the proposed method. Originality/value Most of the existing methods of uncertainty analysis and optimization are merely effective in tackling one uncertainty case. The proposed method is able to handle the uncertain problems involving various types of uncertainties in a unified way.


2019 ◽  
Vol 1 (2) ◽  
pp. 144-156
Author(s):  
Indri Handayani ◽  
Erick Febriyanto ◽  
Andrew Jethro

The lecture support system in Higher Education has information about student identity in each system, such as profile photos, names, NIM (Student Registration Number) and according to system requirements. An assessment on the public viewboard is an Online Assessment System aimed at improving services at Raharja University. However, in the multiplication flow system still has 3 disadvantages, namely, students do not yet have the facility to see the allocation value between friends in one class in one course to be able to improve the results of lecture grades with classmates and also between classes. In class design Popular writers also do five methods, namely the method of analysis, method of literature review, observation method, design method, and then implemented. With the existence of this study, there are 3 Benefits, namely, students can see the value determined by classmates, can improve the value, and lecturers can ensure the value given must be recognized by students.    


2017 ◽  
Vol 8 (4) ◽  
pp. 558-577 ◽  
Author(s):  
Faiza Khan ◽  
Michelle Callanan

Purpose The purpose of this paper is to address the confusing use of terminology associated with tourism undertaken by Muslims and to identify key concerns associated with this type of tourism. Design/methodology/approach This is an exploratory study and adopts a critical review of literature following the evolutionary concept analysis method. Content analysis of popular UK media, UK-based tour operators’ websites and tourism strategies of destinations popular with Muslim tourists were conducted to examine the use of terminology. Findings There is no clear difference between the various terms (halal, Muslim friendly, Islamic, etc.) used. Overall, academia uses the term Islamic tourism, while the industry and media use various terms. Among destinations, however, there is no clear and consistent use of terminology. A key concern of Islamic tourism is the role of certification in assuring travellers and the lack of standardisation of halal certification. Research limitations/implications The paper is based on literature review and secondary data analysis. It lacks primary research. Practical implications This study highlights the need for consistent use of terminology across industry. Another implication is the issue surrounding halal certification of food and the importance of trust in the seller/service provide. Another trend that industry providers need to consider is the growth of the Muslim millennial traveller and the needs of this market segment. Originality/value The paper highlights the importance of studying the Muslim tourist market and provides a starting point for further research. It highlights several issues such as the need to develop a typology of Muslim tourists. Of particular interest is the concern whether halal values in danger of being commodified in the absence of a universal agreed criterion for halal certification.


2016 ◽  
Vol 124 ◽  
pp. 416-421 ◽  
Author(s):  
Leire Kortazar ◽  
Sara Alberdi ◽  
Eithne Tynan ◽  
Luis Angel Fernández

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mahdi Valitabar ◽  
Mohammadjavad Mahdavinejad ◽  
Henry Skates ◽  
Peiman Pilechiha

PurposeThe aim of this paper is to present a parametric design method to generate optimum adaptive facades regarding occupants' comfort and building energy criteria. According to the literature review, the following questions have arisen to address the research gaps: Is it possible to have the outside view throughout the whole year without discomfort glare by utilising adaptive solar facades (ASFs)? How can architects integrate both view quality and quantity into ASF design? What is the impact of dynamic vertical shading systems mounted on south facades on the outside view, occupants' visual comfort and operational energy? How can we evaluate the view quantity through multi-layer shading systems?Design/methodology/approachIn recent years, there is a surge in demand for fully glazed buildings, motivating both architects and scholars to explore novel ideas for designing adaptive solar facades. Nevertheless, the view performance of such systems has not been fully explored especially when it comes to the effect of dynamic vertical shading systems mounted on south facades. This fact clarifies the need to conduct more research in this field by taking into account the window view and natural light. Consequently, a simulation research is carried out to investigate the impact of a dynamic shading system with three vertical slats used on the south facade of a single office room located in Tehran, on both view quality and quantity, visual comfort and operational energy. The research attempts to reach a balance between the occupant's requirements and building energy criteria through a multi-objective optimisation. The distinctive feature of the proposed method is generating some optimum shading which could only cover the essential parts of the window area. It was detected from the simulation results that the usage of a dynamic vertical shading system with multi slats for south facades compared to common Venetian blinds can firstly, provide four times more view quantity. Secondly, the view quality is significantly improved through enabling occupants to enjoy the sky layer the entire year. Finally, twice more operational energy can be saved while more natural light can enter the indoor environment without glare. The final outcome of this research contributes toward designing high-performance adaptive solar facades.FindingsThis paper proposes a new metric to evaluate the view quantity through a multi-layer shading system. The proposed method makes it clear that the usage of dynamic vertical shading systems with multi-layers mounted on south facades can bring many benefits to both occupants and building energy criteria. The proposed method could (1) provide four times more view quantity; (2) improve view quality by enabling occupants to watch the sky layer throughout the whole year; (3) slash the operational energy by twice; (4) keep the daylight glare probability (DGP) value in the imperceptible range.Research limitations/implicationsThe research limitations that should be acknowledged are ignoring the impact of the adjacent building on sunlight reflection, which could cause discomfort glare issues. Another point regarding the limitations of the proposed optimisation method is the impact of vertical shading systems on users' visual interests. A field study ought to be conducted to determine which one could provide the more desirable outside view: a vertical or horizontal the view. Research on the view performance of ASFs, especially their impact on the quality of view, is sorely lacking.Originality/valueThis paper (1) analyses the performance of dynamic vertical shadings on south facades; (2) evaluates outside view through multi-layer shading systems; and (3) integrates both view quality and quantity into designing adaptive solar facades.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guodong Ni ◽  
Ziyao Zhang ◽  
Zhenmin Yuan ◽  
Haitao Huang ◽  
Na Xu ◽  
...  

PurposeThe purpose of this paper is to figure out the paths about transformation of tacit knowledge into explicit knowledge, i.e. tacit knowledge explicating (TKE) in real estate companies, and determine the influencing factors of TKE in Chinese real estate companies to enable enterprises make better use of their knowledge resources.Design/methodology/approachThe study adopted an exploratory design method using thematic analysis and grounded theory, and semi-structured interviews were conducted to collect data. The interviewees consisted of employees in different positions, who come from Chinese real estate companies with different ranking ranges and different knowledge management levels. Data collection was divided into two rounds for the identification of transformation paths and influencing factors.FindingsThis study has shown that 11 paths about TKE divided into solidified organization process and construction of organizational infrastructure go into effect within the real estate companies. Factors influencing TKE in real estate companies concern three main categories: organizational distal factors, contextual proximal factors and individual factors, including 21 subordinates in total. Furthermore, correlation between TKE paths and influencing factors is established.Research limitations/implicationsResearch results may lack generalizability due to the method adopted. Therefore, researchers are encouraged to verify the outcomes of this research.Practical implicationsThis research provides a new idea and solutions for the tacit knowledge management in real estate companies.Originality/valueTo the best of the authors’ knowledge, this study is the first to systematically identify paths and the influencing factors of TKE in real estate companies, contribute to the incipient but growing understanding of achievement of “tacit to explicit” and enrich the corporate tacit knowledge management literature.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Junli Shi ◽  
Junyu Hu ◽  
Mingyang Ma ◽  
Huaizhi Wang

Purpose The purpose of this paper is to present a method for the environmental impact analysis of machine-tool cutting, which enables the detailed analysis of inventory data on resource consumption and waste emissions, as well as the quantitative evaluation of environmental impact. Design/methodology/approach The proposed environmental impact analysis method is based on the life cycle assessment (LCA) methodology. In this method, the system boundary of the cutting unit is first defined, and inventory data on energy and material consumptions are analyzed. Subsequently, through classification, five important environmental impact categories are proposed, namely, primary energy demand, global warming potential, acidification potential, eutrophication potential and photochemical ozone creation potential. Finally, the environmental impact results are obtained through characterization and normalization. Findings This method is applied on a case study involving a machine-tool turning unit. Results show that primary energy demand and global warming potential exert the serious environmental impact in the turning unit. Suggestions for improving the environmental performance of the machine-tool turning are proposed. Originality/value The environmental impact analysis method is applicable to different machine tools and cutting-unit processes. Moreover, it can guide and support the development of green manufacturing by machinery manufacturers.


Author(s):  
Zunling Du ◽  
Yimin Zhang

Axial piston pumps (APPs) are the core energy conversion components in a hydraulic transmission system. Energy conversion efficiency is critically important for the performance and energy-saving of the pumps. In this paper, a time-varying reliability design method for the overall efficiency of APPs was established. The theoretical and practical instantaneous torque and flow rate of the whole APP were derived through comprehensive analysis of a single piston-slipper group. Moreover, as a case study, the developed model for the instantaneous overall efficiency was verified with a PPV103-10 pump from HYDAC. The time-variation of reliability for the pump was revealed by a fourth-order moment technique considering the randomness of working conditions and structure parameters, and the proposed reliability method was validated by Monte Carlo simulation. The effects of the mean values and variance sensitivity of random variables on the overall efficiency reliability were analyzed. Furthermore, the optimized time point and design variables were selected. The optimal structure parameters were obtained to meet the reliability requirement and the sensitivity of design variables was significantly reduced through the reliability-based robust design. The proposed method provides a theoretical basis for designers to improve the overall efficiency of APPs in the design stage.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dmytro S. Melnyk ◽  
Oleg A. Parfylo ◽  
Oleksii V. Butenko ◽  
Olena V. Tykhonova ◽  
Volodymyr O. Zarosylo

Purpose The experience of most European Union (EU) Member States has demonstrated effective anti-corruption practices, making the EU one of the leaders in this field, which can be used as an example to learn from in the field of anti-corruption. The purpose of this study is to analyze and identify the main features of anti-corruption legislation and strategies to prevent corruption at the national and supranational levels of the EU. Design/methodology/approach The following methods were used in the work: discourse and content analysis, method of system analysis, method of induction and deduction, historical-legal method, formal-legal method, comparative-legal method and others. Using the historical and legal method, the evolution of the formation of anti-corruption regulation at the supranational level was revealed. The comparative law method helped to compare the practices of the Member States of the EU in the field of anti-corruption regulation. The formal-legal method is used for generalization, classification and systematization of research results, as well as for the correct presentation of these results. Findings The main results, prospects for further research and the value of the material. The paper offers a critical review of key EU legal instruments on corruption, from the first initiatives taken in the mid-1990s to recent years. Originality/value In addition, the article analyzes the relevant anti-corruption legislation in the EU member states that are in the top 10 countries with the lowest level of corruption, namely: Denmark, Finland, Sweden, the Netherlands, Germany and Luxembourg.


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