scholarly journals Oil Friction Loss Evaluation of Oil-Immersed Cooling In-Wheel Motor Based on Improved Analytical Method and VOF Model

2021 ◽  
Vol 12 (4) ◽  
pp. 164
Author(s):  
Yi Yin ◽  
Hui Li ◽  
Xuewei Xiang
Keyword(s):  
Analytical Method ◽  
Fluid Dynamic ◽  
Complex Structure ◽  
Three Dimensional ◽  
Friction Loss ◽  
Future Research ◽  
Compact Structure ◽  
Cooling Method ◽  
Output Torque ◽  
Vof Model

Oil-immersed cooling provides an effective cooling scheme for high-power hub motors with compact structure and serious heating problems. However, with this cooling method, some oil friction loss will be generated, making the output torque and efficiency of the motor lower, which limits its application in the motor. It is essential to get an exact calculation of the oil friction loss so that it can be reduced in the future research. Firstly, a new method was proposed to improve the accuracy of oil friction loss calculated by an existing analytical method (Kori’s method), while the influence laws of oil-soaked depth and rotation speed on it were explored. Secondly, a three-dimensional transient Computational Fluid Dynamic (CFD) model based on Volume of Fluid (VOF) was established, considering the actual complex structure and the disorderly mixing of oil and air inside the motor. Finally, the oil friction loss calculated with an improved analytical method and a VOF model was verified by a testing. It was indicated that the VOF model was more precise but more time-consuming. The proposed method has the second highest accuracy but takes less time.

FRAMEWORK OF WIND–VEHICLE–BRIDGE INTERACTION ANALYSIS AND ITS APPLICATIONS

2013 ◽  
Vol 07 (03) ◽  
pp. 1350020 ◽  
Author(s):  
C. S. CAI ◽  
WEI ZHANG ◽  
XIANZHI LIU ◽  
WEI PENG ◽  
S. R. CHEN ◽  
...  
Keyword(s):  
Interaction Analysis ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Dynamic Responses ◽  
Future Research ◽  
Element Analysis ◽  
Long Span Bridges ◽  
Safety Issues ◽  
Wind Speeds ◽  
Moving Vehicles

Under strong winds, bridges may exhibit large dynamic responses. Wind may also endanger the safety of moving vehicles on the roadways as well as on bridges. For regular aerodynamic study of long-span bridges, traffic loads are not typically considered, assuming that bridges will be closed to traffic at high wind speeds. Therefore, bridges are usually tested in wind tunnels or analyzed numerically without considering moving vehicles on them. However, there are numerous possible scenarios under which vehicles may still be on the bridge when higher wind speeds occur. These scenarios include unexpected increase in hurricane forward speed or intensity, evacuation traffic gridlock, accidents/stalled vehicles or rainfall flooding blocking the road ahead, etc. Wind, together with vehicles, will also cause serviceability and bridge fatigue damage issues. The present study will present the framework of wind–vehicle–bridge interaction analysis and its applications, developed in the last decade by the authors' group, focused on the vehicle and bridge safety issues. It consists of the following five parts: (1) A three dimensional finite element analysis framework considering the interaction of wind, bridge and vehicles; (2) experimental facilities development and studies for both static and aerodynamic tests of bridge section models and vehicles; (3) Computation fluid dynamic (CFD) prediction of loading on vehicles; (4) performance evaluation of vehicle safety and bridge fatigue; and (5) bridge vibration mitigations. Case study will also be presented and future research needs are discussed.

scholarly journals Two Dimensional CFD Analysis and Flow Optimization of Transmission Cooling Scoop for Longitudinal Powertrain Applications

2021 ◽  
Vol 2 (1) ◽  
pp. 11-21
Author(s):  
Jacob Viertel ◽  
Rachmadian Wulandana
Keyword(s):  
Heat Transfer ◽  
Energy Input ◽  
Three Dimensional ◽  
Ambient Air ◽  
Future Research ◽  
Two Dimensional ◽  
Flow Optimization ◽  
Future Design ◽  
Cooling Method ◽  
Dimensional Simulation

Two dimensional finite area method simulation was conducted to optimize the convective cooling performance of a transmission cooling scoop for longitudinal vehicle powertrain applications. Cooling of the transmission in an automobile is important to prevent premature wear or sudden failure caused by prolonged overheating of internal transmission components. The most common method for transmission cooling requires a small energy input for powering a pump to cool the transmission by circulating transmission fluid through a heat exchanger. An alternative cooling method was designed utilizing a simple scoop geometry to induce forced convection from ambient air to cool the transmission with no energy input requirement. Two dimensional simulation of this alternative cooling method was conducted in ANSYS Fluent. Fluid flow and heat transfer performance were analyzed for three proposed cooling scoop designs. Further flow optimization was achieved with parametric study regarding angle at which the cooling scoop is positioned relative to the transmission. Three dimensional simulation was conducted for improved observation of the physical model. Based on the simulation results, optimal geometry and future design improvements have been determined. A peak simulated heat transfer of 11.14 kW/m^2 was achieved with scoop angle of 45 degrees. Future research investigating the effects of induced turbulence to improve convective heat transfer would be beneficial.

Part Design and Analysis of Cycloid Installation Systems

2014 ◽  
Vol 539 ◽  
pp. 51-54 ◽  
Author(s):  
Chang Ji Shan ◽  
Yi Duo Bian ◽  
Lin Li
Keyword(s):  
Small Volume ◽  
High Efficiency ◽  
Load Capacity ◽  
Complex Structure ◽  
Three Dimensional ◽  
Working Environment ◽  
Light Weight ◽  
High Demand ◽  
Compact Structure ◽  
And Performance

Cycloidal gear requires rigidly a certain working environment, so its installation and part designing also calls for the greatest care. This paper intends to analyse and design the structure of system components and to conduct a feasibility study based on actual requirements. Three-dimensional drawing software is applied to aid to minimize any error in part designing and upgrade the designing efficiency. Cycloidal pin wheel is featured by compact structure, small volume, light weight, high efficiency, smooth operation, good load capacity and performance against impact and vibration. However, at the same time, owing to its complex structure, difficult manufacture, high demand of precision for processing and assembly, it is very important to design the cycloidal gear system

Development and Construct Validation of the German Workplace Trust Survey (G-WTS)

2010 ◽  
Vol 26 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Nale Lehmann-Willenbrock ◽  
Simone Kauffeld
Keyword(s):  
Convergent Validity ◽  
Affective Commitment ◽  
Discriminant Validity ◽  
Organizational Context ◽  
Organizational Trust ◽  
Three Dimensional ◽  
Future Research ◽  
Work Related ◽  
Reliable Assessment ◽  
Workplace Trust

In research on trust in the organizational context, there is some agreement evolving that trust should be measured with respect to various foci. The Workplace Trust Survey (WTS) by Ferres (2002) provides reliable assessment of coworker, supervisor, and organizational trust. By means of a functionally equivalent translation, we developed a German version of the questionnaire (G-WTS) comprising 21 items. A total of 427 employees were surveyed with the G-WTS and questionnaires concerning several work-related attitudes and behaviors and 92 of these completed the survey twice. The hypothesized three-dimensional conceptualization of organizational trust was confirmed by confirmatory factor analysis. The G-WTS showed good internal consistency and retest reliability values. Concerning convergent validity, all of the three G-WTS dimensions positively predicted job satisfaction. In terms of discriminant validity, Coworker Trust enhanced group cohesion; Supervisor Trust fostered innovative behavior, while Organizational Trust was associated with affective commitment. Theoretical and practical contributions as well as opportunities for future research with the G-WTS are discussed.

scholarly journals Biomechanical-Structural Correlation of Chordae tendineae in Animal Models: A Pilot Study

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1678
Author(s):  
Justyn Gach ◽  
Izabela Janus ◽  
Agnieszka Mackiewicz ◽  
Tomasz Klekiel ◽  
Agnieszka Noszczyk-Nowak
Keyword(s):  
Mitral Valve ◽  
Complex Structure ◽  
Future Research ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Histopathological Analysis ◽  
Papillary Muscles ◽  
Chordae Tendineae ◽  
Structural Correlation ◽  
Ring Valve

The mitral valve apparatus is a complex structure consisting of the mitral ring, valve leaflets, papillary muscles and chordae tendineae (CT). The latter are mainly responsible for the mechanical functions of the valve. Our study included investigations of the biomechanical and structural properties of CT collected from canine and porcine hearts, as there are no studies about these properties of canine CT. We performed a static uniaxial tensile test on CT samples and a histopathological analysis in order to examine their microstructure. The results were analyzed to clarify whether the changes in mechanical persistence of chordae tendineae are combined with the alterations in their structure. This study offers clinical insight for future research, allowing for an understanding of the process of chordae tendineae rupture that happens during degenerative mitral valve disease—the most common heart disease in dogs.

scholarly journals Three-Dimensional Thematic Map Imaging of the Yacht Port on the Example of the Polish National Sailing Centre Marina in Gdańsk

2021 ◽  
Vol 11 (15) ◽  
pp. 7016
Author(s):  
Pawel S. Dabrowski ◽  
Cezary Specht ◽  
Mariusz Specht ◽  
Artur Makar
Keyword(s):  
Spatial Data ◽  
Convex Surface ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Future Research ◽  
Two Dimensional ◽  
Thematic Maps ◽  
Research Directions ◽  
Future Research Directions ◽  
The Many

The theory of cartographic projections is a tool which can present the convex surface of the Earth on the plane. Of the many types of maps, thematic maps perform an important function due to the wide possibilities of adapting their content to current needs. The limitation of classic maps is their two-dimensional nature. In the era of rapidly growing methods of mass acquisition of spatial data, the use of flat images is often not enough to reveal the level of complexity of certain objects. In this case, it is necessary to use visualization in three-dimensional space. The motivation to conduct the study was the use of cartographic projections methods, spatial transformations, and the possibilities offered by thematic maps to create thematic three-dimensional map imaging (T3DMI). The authors presented a practical verification of the adopted methodology to create a T3DMI visualization of the marina of the National Sailing Centre of the Gdańsk University of Physical Education and Sport (Poland). The profiled characteristics of the object were used to emphasize the key elements of its function. The results confirmed the increase in the interpretative capabilities of the T3DMI method, relative to classic two-dimensional maps. Additionally, the study suggested future research directions of the presented solution.

scholarly journals An Exit Strategy for the Definitional Elusiveness: A Three-Dimensional Framework for Social Entrepreneurship

2021 ◽  
Vol 13 (2) ◽  
pp. 563
Author(s):  
Bing Ran ◽  
Scott Weller
Keyword(s):  
Social Change ◽  
Literature Review ◽  
Systematic Literature Review ◽  
Social Entrepreneurship ◽  
Common Ground ◽  
Three Dimensional ◽  
Theoretical Framework ◽  
Future Research ◽  
Exit Strategy ◽  
Conceptual Paper

Despite the growing utility and prevalence of social entrepreneurship, an accepted definition remains elusive and infeasible. Yet, it is imperative that the principles guiding social entrepreneurship are identified so that common ground is established to facilitate future research. On the basis of a systematic literature review, this conceptual paper proposes a theoretical framework outlining social entrepreneurship as a three-dimensional framework as a function of continua of “social” and “business” logics, “beneficial” and “detrimental” social change logics, and “innovation” and “mundane” logics. The framework accommodates the fuzziness and ambiguity associated with social entrepreneurship whilst remaining a workable, identifiable construct. By accounting for the shifting logics practiced by social entrepreneurship that both influence and are influenced by the organizational environment, this framework provides an exit strategy for the definitional elusiveness of social entrepreneurship. The resultant structures and functions of social entrepreneurship are shaped by these constraints as reflected by the fluidity and flexibility endorsed by the framework. Four avenues for future research regarding social entrepreneurship are recommended on the basis of the framework proposed in this article.

scholarly journals Combining Virtual Reality and Organizational Neuroscience for Leadership Assessment

2021 ◽  
Vol 11 (13) ◽  
pp. 5956
Author(s):  
Elena Parra ◽  
Irene Alice Chicchi Giglioli ◽  
Jestine Philip ◽  
Lucia Amalia Carrasco-Ribelles ◽  
Javier Marín-Morales ◽  
...  
Keyword(s):  
Machine Learning ◽  
Eye Tracking ◽  
Ecological Validity ◽  
Objective Assessment ◽  
Leadership Skills ◽  
Three Dimensional ◽  
Machine Learning Techniques ◽  
Future Research ◽  
Promising Tool ◽  
Future Research Agenda

In this article, we introduce three-dimensional Serious Games (3DSGs) under an evidence-centered design (ECD) framework and use an organizational neuroscience-based eye-tracking measure to capture implicit behavioral signals associated with leadership skills. While ECD is a well-established framework used in the design and development of assessments, it has rarely been utilized in organizational research. The study proposes a novel 3DSG combined with organizational neuroscience methods as a promising tool to assess and recognize leadership-related behavioral patterns that manifest during complex and realistic social situations. We offer a research protocol for assessing task- and relationship-oriented leadership skills that uses ECD, eye-tracking measures, and machine learning. Seamlessly embedding biological measures into 3DSGs enables objective assessment methods that are based on machine learning techniques to achieve high ecological validity. We conclude by describing a future research agenda for the combined use of 3DSGs and organizational neuroscience methods for leadership and human resources.

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