scholarly journals Design Methodology of Conical Section Shape for Supercavitating Vehicles considering Auto-Oscillation Characteristics

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Daijin Li ◽  
Fengjie Li ◽  
Kan Qin ◽  
Chuang Huang ◽  
Kai Luo
Keyword(s):  
Design Methodology ◽  
Gas Flow ◽  
Integrated Design ◽  
Maximum Amplitude ◽  
Euler Angle ◽  
Cross Sectional ◽  
Supercavitating Vehicles ◽  
Section Shape ◽  
Conical Section ◽  
Oscillation Characteristics

Due to the complexity of the cavity/vehicle and oscillation characteristics, streamlined shape integrated design of conventional fully wetted vehicles is not suitable for supercavitating vehicles. In this paper, a set of design criteria is highlighted to optimize the length and streamlined shape of a conical section subjected to realistic design constraints, which integrate the complex characteristics of the cavity/vehicle system under the condition of auto-oscillation of supercavitating vehicles. The auto-oscillation and its time-domain characteristics are determined. By deriving the equation describing the cavity/vehicle relationship and identifying the maximum amplitude of the Euler angle, the cavity/vehicle tangent point criterion is proposed to determine the theoretical optimum value of the length of the conical section. A method of equal cross-sectional area for gas flow is proposed to design the streamlined shape of the conical section. Water tunnel and autonomous flight experiments were carried out to validate the feasibility of the design methodology developed in this work.

scholarly journals APPLICATION OF DOMAIN INTEGRATED DESIGN METHODOLOGY FOR BIO-INSPIRED DESIGN- A CASE STUDY OF SUTURE PIN DESIGN

2021 ◽  
Vol 1 ◽  
pp. 487-496
Author(s):  
Pavan Tejaswi Velivela ◽  
Nikita Letov ◽  
Yuan Liu ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Cross Sections ◽  
Design Methodology ◽  
Reaction Force ◽  
Integrated Design ◽  
Total Deformation ◽  
Insertion Force ◽  
Force Reaction ◽  
The Moment ◽  
Work Done

AbstractThis paper investigates the design and development of bio-inspired suture pins that would reduce the insertion force and thereby reducing the pain in the patients. Inspired by kingfisher's beak and porcupine quills, the conceptual design of the suture pin is developed by using a unique ideation methodology that is proposed in this research. The methodology is named as Domain Integrated Design, which involves in classifying bio-inspired structures into various domains. There is little work done on such bio-inspired multifunctional aspect. In this research we have categorized the vast biological functionalities into domains namely, cellular structures, shapes, cross-sections, and surfaces. Multi-functional bio-inspired structures are designed by combining different domains. In this research, the hypothesis is verified by simulating the total deformation of tissue and the needle at the moment of puncture. The results show that the bio-inspired suture pin has a low deformation on the tissue at higher velocities at the puncture point and low deformation in its own structure when an axial force (reaction force) is applied to its tip. This makes the design stiff and thus require less force of insertion.

Examining the influence of mindfulness on organizational role stress (ORS): a monitor acceptance theory perspective

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Uma Warrier ◽  
Cyril Foropon ◽  
Melinda Chehimi
Keyword(s):  
Design Methodology ◽  
Negative Relationship ◽  
Role Stress ◽  
Role Overload ◽  
Cross Sectional ◽  
Content Type ◽  
Organizational Role ◽  
It Organization ◽  
Context Specific ◽  
Personal Inadequacy

PurposeThe purpose of this paper is to examine the influence of mindfulness on organizational role stress (ORS) based on the Monitor Acceptance Theory (MAT) perspective.Design/methodology/approachThis study is based on a cross-sectional data analysis collected from 137 employees working at an Indian IT organization located in Bangalore (India). ORS and MAAS scales have been used for measuring ORS and mindfulness, respectively.FindingsOverall, the study findings have indicated a negative relationship (r = −0.588) between mindfulness (M) and ORS. First, both personal inadequacy (PI) and self-role distance (SRD) are found to be predominantly impacted by M, whereas both role erosion (RE) and role overload (RO) appear to be less affected by mindfulness. Second, SRD appears to be the highest ORS sub-dimension among IT employees. Third, building on the extant literature, it can be inferred that “no one size fits all”, ORS is both organization and context specific.Originality/valueThis study pioneers to establish empirical evidence between M and ORS. Training employees on M can help in effectively handling ORS.

The impact of the COVID-19 pandemic on autistic adults – a survey

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Conor James Davidson ◽  
Keri Lodge ◽  
Alwyn Kam
Keyword(s):  
Coping Strategies ◽  
Design Methodology ◽  
Online Survey ◽  
Negative Impact ◽  
Significant Deterioration ◽  
Cross Sectional ◽  
Content Type ◽  
Autistic People ◽  
Autistic Adults ◽  
The Impact

Purpose To date there has been limited research on the impact of the COVID-19 pandemic on autistic people. This study aims to present the results of a survey of autistic people (n = 51) conducted by a UK specialist autism team. Design/methodology/approach A cross-sectional online survey. Findings A total of 72% respondents reported either some or significant deterioration in mental health during the pandemic. The issues that caused most negative impact were uncertainty over what will happen next and disruption of normal routine. Respondents reported a variety of coping strategies to help them through the pandemic. Originality/value To date there has been little research looking specifically at the impact of the COVID-19 pandemic on autistic people. This paper adds weight to the evidence that the pandemic has had a particularly severe impact on autistic adults and includes useful information on potential coping strategies for this population.

Publishing quantitative careers research: challenges and recommendations

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bert Schreurs ◽  
Angus Duff ◽  
Pascale M. Le Blanc ◽  
Thomas H. Stone
Keyword(s):  
Design Methodology ◽  
Team Member ◽  
Research Question ◽  
Editorial Team ◽  
Board Members ◽  
Decision Making Process ◽  
Cross Sectional ◽  
Content Type ◽  
Insight Into

Purpose This article aims to provide prospective authors guidelines that will hopefully enable them to submit more competitive manuscripts to journals publishing careers research.Design/methodology/approach Based on their experience as an author, reviewer and editorial team member, the authors identify the main criteria that a quantitative study must meet to be considered for publication in international peer-reviewed journals covering career-related topics. They emphasize the importance of contributing to the careers literature and of designing the study in accordance with the research question.Findings Manuscripts are rejected because they are insufficiently innovative, and/or because sample, instruments and design are not appropriate to answer the research question at hand. Cross-sectional designs cannot be used to answer questions of mediation but should not be discarded automatically since they can be used to address other types of questions, including questions about nesting, clustering of individuals into subgroups, and to some extent, even causality.Originality/value The manuscript provides an insight into the decision-making process of reviewers and editorial board members and includes recommendations on the use of cross-sectional data.

Numerical Investigation of the Effect of Diffuser and Volute Design Parameters on the Performance of a Centrifugal Compressor Stage

2016 ◽  
Author(s):  
Lei Yu ◽  
William T. Cousins ◽  
Feng Shen ◽  
Georgi Kalitzin ◽  
Vishnu Sishtla ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Gas Flow ◽  
Pressure Rise ◽  
Design Parameters ◽  
Compressor Stage ◽  
Flow Distortion ◽  
Cross Sectional ◽  
Centrifugal Stage ◽  
And Performance ◽  
The Impact

In this effort, 3D CFD simulations are carried out for real gas flow in a refrigeration centrifugal compressor. Both commercial and the in-house CFD codes are used for steady and unsteady simulations, respectively. The impact on the compressor performance with various volute designs and diffuser modifications are investigated with steady simulations and the analysis is focused on both the diffuser and the volute loss, in addition to the flow distortion at impeller exit. The influence of the tongue, scroll diffusion ratio, diffuser length, and cross sectional area distribution is examined to determine the impact on size and performance. The comparisons of total pressure loss, static pressure recovery, through flow velocity, and the secondary flow patterns for different volute designs show that the performance of the centrifugal compressor depends upon how well the scroll portion of the volute collects the flow from the impeller and achieves the required pressure rise with minimum flow losses in the overall diffusion process. Finally, the best design is selected based on compressor stage pressure rise and peak efficiency improvement. An unsteady simulation of the full wheel compressor stage was carried out to further examine the interaction of impeller, diffuser and the volute. The unsteady flow interactions are shown to have a major impact on the performance of the centrifugal stage.

Relationship between corporate governance and audit switching: Iranian evidence

2017 ◽  
Vol 59 (5) ◽  
pp. 673-686
Author(s):  
Mahdi Salehi ◽  
Ali Asgar Alinya
Keyword(s):  
Corporate Governance ◽  
Design Methodology ◽  
Stock Exchange ◽  
Listed Companies ◽  
Panel Analysis ◽  
Cross Sectional ◽  
Content Type ◽  
Effective Factors ◽  
Dependent Variables ◽  
The Relationship

Purpose This paper aims to investigate the relationship between corporate governance and auditors switching of listed companies on the Tehran Stock Exchange. Design/methodology/approach To achieve the objectives of this study, 12 hypotheses developed which and tests the relationship between corporate governance and selecting and switching auditors in Iran during 2008-20014 by selecting 116 listed companies on the Tehran Stock Exchange. To test the hypotheses, the cross-sectional time-series nature of research variables data, panel analysis is used. Also, to investigate the relationship between independent and dependent variables in each year, the logistic regression is used. Findings The results of the study indicate that there is a weak relationship between corporate governance auditors switching. Therefore, it could be concluded that there are some other effective factors on which selecting and switching auditors in studied companies are more dependent. Originality/value The current study is almost the first study which has been conducted in Iran, so the results of the study may be beneficial to the Iranian conditions as well as other developing countries.

Fanno Design of Blow-Off Lines in Heavy Duty Gas Turbine

2013 ◽  
Author(s):  
Marco Cioffi ◽  
Enrico Puppo ◽  
Andrea Silingardi
Keyword(s):  
Gas Turbines ◽  
Gas Flow ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Design Procedure ◽  
Flow Equation ◽  
Heavy Duty ◽  
Cross Sectional ◽  
Pipe Length ◽  
Choked Flow

In typical heavy duty gas turbines the multistage axial compressor is provided with anti-surge pipelines equipped with on-off valves (blow-off lines), to avoid dangerous flow instabilities during start-ups and shut-downs. Blow-off lines show some very peculiar phenomena and somewhat challenging fluid dynamics, which require a deeper regard. In this paper the blow-off lines in axial gas turbines are analyzed by adopting an adiabatic quasi-unidimensional model of the gas flow through a pipe with a constant cross-sectional area and involving geometrical singularities (Fanno flow). The determination of the Fanno limit, on the basis of the flow equation and the second principle of thermodynamics, shows the existence of a critical pipe length which is a function of the pipe parameters and the initial conditions: for a length greater than this maximum one, the model requires a mass-flow reduction. In addition, in the presence of a regulating valve, so-called multi-choked flow can arise. The semi-analytical model has been implemented and the results have been compared with a three-dimensional CFD analysis and cross-checked with available field data, showing a good agreement. The Fanno model has been applied for the analysis of some of the actual machines in the Ansaldo Energia fleet under different working conditions. The Fanno tool will be part of the design procedure of new machines. In addition it will define related experimental activities.

scholarly journals AN INTEGRATED DESIGN METHODOLOGY

2011 ◽  
Author(s):  
T. Freiheit ◽  
S. S. Park ◽  
V Giuliani
Keyword(s):  
Design Methodology ◽  
Integrated Design ◽  
Cost Effective ◽  
Global Markets ◽  
Design Tools ◽  
Regulatory Requirements ◽  
Life Cycle Design ◽  
Design Requirements ◽  
Stakeholder Needs ◽  
Integrated Design Methodology

Global markets demand quick product develop-ment that is simultaneously cost-effective and meets stakeholder needs. Many tools and design methodolo-gies have been developed that address individual as-pects of the design problem, such as Axiomatic De-sign, Design for Manufacture, Life Cycle Design, etc. However, competitive viability can be put at risk when a product fails to achieve all customer, business, manufacturing, and regulatory requirements. To de-liver all design requirements, an efficient integrated design methodology is required. This paper proposes a design approach which integrates previously devel-oped design tools to economically achieve essential design objectives, within a framework that facilitates a rapid design process.

Employees’ eldercare demands, strain, and perceived support

2015 ◽  
Vol 30 (2) ◽  
pp. 183-198 ◽  
Author(s):  
Hannes Zacher ◽  
Heiko Schulz
Keyword(s):  
Design Methodology ◽  
Self Report ◽  
Perceived Support ◽  
Use Of Self ◽  
Cross Sectional ◽  
Content Type ◽  
Cross Sectional Design ◽  
The Relationship ◽  
Practical Implications ◽  
Employed Caregivers

Purpose – In many countries, both the number of older people in need of care and the number of employed caregivers of elderly relatives will increase over the next decades. The purpose of this paper is to examine the extent to which perceived organizational, supervisor, and coworker support for eldercare reduce employed caregivers’ strain and weaken the relationship between eldercare demands and strain. Design/methodology/approach – Survey data were collected from 100 employed caregivers from one organization. Findings – Results showed that eldercare demands were positively related to strain, and perceived organizational eldercare support (POES) was negatively related to strain. In addition, high POES weakened the relationship between eldercare demands and strain. Research limitations/implications – The cross-sectional design and use of self-report scales constitute limitations of the study. Practical implications – POES is a resource for employed caregivers, especially when their eldercare demands are high. Originality/value – This research highlights the relative importance of different forms of perceived support for reducing employed caregivers’ strain and weakening the relationship between eldercare demands and strain.

Sign in / Sign up

Export Citation Format

Share Document