scholarly journals Ground Test Stands for Testing Rotors in Insulated Conditions

2021 ◽  
Vol 2021 (1) ◽  
pp. 15-23
Author(s):  
Małgorzata Wojtas ◽  
Łukasz Czajkowski ◽  
Kazimierz Szumański
Keyword(s):  
Test Stand ◽  
Research Network ◽  
Online Data ◽  
Basic Assumptions ◽  
Universal Test ◽  
Rotor Design ◽  
Different Types ◽  
Ground Test ◽  
Similar Solutions

Abstract The paper generally discusses Whirl Tower research stands. Whirl Tower stands are used to test, among others, rotorcrafts main rotors in hovering. The work presents an overview of similar solutions of test stand presented in the available literature and online data. Beyond these solutions the paper also contains test stands used so far at the Institute of Aviation, these solutions were prepared for testing one type of rotor (for example: only for gyroplane rotors). The article provides information about new (Whirl Tower) test stand fully designed and manufactured in Łukasiewicz Research Network ‒ Institute of Aviation (Ł-ILOT). One of the basic assumptions is that it will be a universal test stand, giving the possibility to test different types of rotors. Moreover, the article discusses the types of tests and research that can be carried out on this type of test stand, tests that are performed to ensure the safety of the rotor design.

scholarly journals A Prototype Test Stand for Testing Insolated Rotor Systems

2019 ◽  
Vol 26 (3) ◽  
pp. 257-264
Author(s):  
Małgorzata Wojtas ◽  
Łukasz Czajkowski
Keyword(s):  
Free Vibrations ◽  
Test Stand ◽  
Helicopter Rotors ◽  
Rotor Systems ◽  
Advantages And Disadvantages ◽  
Prototype Test ◽  
Different Types ◽  
Similar Solutions ◽  
Electric Engine ◽  
Conditions Of Work

Abstract The article discusses assumptions for a prototype test stand designed for testing rotors in the conditions of work at their nominal speed, in particular gyrocopter and helicopter rotors. In the work presents an overview of similar solutions of test stand presented in the available literature and solutions proposed by companies, such as Swangate International or Luftfahrttechnik GmbH. Beyond these solutions the article also contains test stand used so far at the Institute of Aviation, these solutions were prepared for testing one type of rotor (for example: only for gyroplane rotors). The article provides the steps of designing a new test stand, which one of the basic assumptions is that it will be a universal test stand, giving the possibility to test different types of rotors. The article discusses two concepts of the stand with electric engine as a drive, gives the advantages and disadvantages of each concept, and indicates the selected solution. In addition to design and applied drive solution of the stand, the measuring part and data acquisition were also discussed. Moreover, the article focus on the advantages of rotor testing using the presented solution, as well as problems encountered during tests, in particular related to construction free vibrations and resonance. Vibration and resonance of the test stand are very important aspect of the entire design process, because it affects the quality and safety of the tests.

scholarly journals Design and Research on Power Systems and Algorithms for Controlling Electric Underground Mining Machines Powered by Batteries

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4060
Author(s):  
Artur Kozłowski ◽  
Łukasz Bołoz
Keyword(s):  
Power Systems ◽  
Power Supply ◽  
Internal Combustion Engines ◽  
Underground Mining ◽  
Test Stand ◽  
Research Network ◽  
Control Algorithms ◽  
Systems And Control ◽  
And Control ◽  
Supply Systems

This article discusses the work that resulted in the development of two battery-powered self-propelled electric mining machines intended for operation in the conditions of a Polish copper ore mine. Currently, the global mining industry is seeing a growing interest in battery-powered electric machines, which are replacing solutions powered by internal combustion engines. The cooperation of Mine Master, Łukasiewicz Research Network—Institute of Innovative Technologies EMAG and AGH University of Science and Technology allowed carrying out a number of works that resulted in the production of two completely new machines. In order to develop the requirements and assumptions for the designed battery-powered propulsion systems, underground tests of the existing combustion machines were carried out. Based on the results of these tests, power supply systems and control algorithms were developed and verified in a virtual environment. Next, a laboratory test stand for validating power supply systems and control algorithms was developed and constructed. The tests were aimed at checking all possible situations in which the battery gets discharged as a result of the machine’s ride or operation and when it is charged from the mine’s mains or with energy recovered during braking. Simulations of undesirable situations, such as fluctuations in the supply voltage or charging power limitation, were also carried out at the test stand. Positive test results were obtained. Finally, the power supply systems along with control algorithms were implemented and tested in the produced battery-powered machines during operational trials. The power systems and control algorithms are universal enough to be implemented in two different types of machines. Both machines were specially designed to substitute diesel machines in the conditions of a Polish ore mine. They are the lowest underground battery-powered drilling and bolting rigs with onboard chargers. The machines can also be charged by external fast battery chargers.

scholarly journals Analysis of the self-similar solutions of a generalized Burger's equation with nonlinear damping

2001 ◽  
Vol 7 (3) ◽  
pp. 253-282 ◽  
Author(s):  
Ch. Srinivasa Rao ◽  
P. L. Sachdev ◽  
Mythily Ramaswamy
Keyword(s):  
Initial Conditions ◽  
Nonlinear Damping ◽  
Nonlinear Ordinary Differential Equation ◽  
The Self ◽  
Similar Reduction ◽  
Generalized Burgers Equation ◽  
Different Types ◽  
Self Similar ◽  
Parameter Ranges ◽  
Similar Solutions

The nonlinear ordinary differential equation resulting from the self-similar reduction of a generalized Burgers equation with nonlinear damping is studied in some detail. Assuming initial conditions at the origin we observe a wide variety of solutions – (positive) single hump, unbounded or those with a finite zero. The existence and nonexistence of positive bounded solutions with different types of decay (exponential or algebraic) to zero at infinity for specific parameter ranges are proved.

UNIVERSAL TEST STAND FOR RESEARCH OF AERONAUTICAL MULTI-POWER PATH GEAR DEMONSTRATORS

2015 ◽  
Vol 19 (3) ◽  
pp. 233-238 ◽  
Author(s):  
Bogdan Kozik ◽  
Grzegorz Budzik ◽  
Mariusz Cieplak
Keyword(s):  
Test Stand ◽  
Universal Test

scholarly journals Four scenarios for determining the size and reusability of learning objects

2012 ◽  
Vol 28 (2) ◽  
Author(s):  
Judit Schoonenboom
Keyword(s):  
Higher Education ◽  
Grounded Theory ◽  
Field Test ◽  
Learning Objects ◽  
Theory Analysis ◽  
Basic Assumptions ◽  
Different Types ◽  
Definition Of

<span>The best method for determining the size of learning objects (LOs) so as to optimise their reusability has been a topic of debate for years now. Although there appears to be agreement on basic assumptions, developed guidelines and principles are often in conflict. This study shows that this confusion stems from the fact that in the literature, hardly any attention is paid to different types of reusability. This study not only shows that there are different types of reusability, but also that different types of reusability go together with different principles for developing LOs and for determining LO size. A grounded theory analysis was performed on separate statements on LO development in 71 selected publications from LO literature. This resulted in the development of four scenarios for LO development, each with their own definition of reusability and their own principle for determining the size of LOs. A field test with 11 experts showed that the scenarios are recognisable. In higher education, educational technologists often assist amateur LO developers. Educational technologists can use the scenarios to determine which definition of reusability is applicable to their situation and which principle for determining the size of LOs should be applied.</span>

Impact of Passenger Trains in Double Track Networks

2012 ◽  
Author(s):  
Samuel L. Sogin ◽  
Christopher P. L. Barkan ◽  
Yung-Cheng Lai ◽  
Mohd Rapik Saat
Keyword(s):  
Relative Difference ◽  
Simulation Software ◽  
Heterogeneous Traffic ◽  
Simultaneous Operation ◽  
Basic Assumptions ◽  
Different Types ◽  
Catch Up ◽  
Passenger Trains ◽  
Double Track ◽  
The Impact

North American freight railroads are expected to experience increasing capacity constraints across their networks. To help plan for this increased traffic, railroads use simulation software to analyze the benefits of capacity expansion projects. Simultaneous operation of heterogeneous traffic further increases delay relative to additional homogenous traffic. Additional passenger trains can cause more delays to freight trains than additional freight trains. Rail Traffic Controller (RTC) was used to run simulations with varying mixes of unit freight and passenger trains operating at various speeds on a double track configuration. Basic assumptions on the relative difference in priority between train types lead to drastically different results on the impact of adding higher priority trains. This assumption dictates whether the track in the opposing direction should be used for overtake maneuvers. Also, higher speed differentials between train types can result in higher delays as faster trains catch up to slower trains more quickly. These analyses will help planners improve their understanding of the tradeoff in capacity due to operation of different types of trains at different priorities and speeds.

Development of Pipe Flow Generators

2011 ◽  
Vol 233-235 ◽  
pp. 2432-2438
Author(s):  
Song Hao Wang ◽  
Ronald José Doblado Perez ◽  
Ronald García ◽  
Jia Cheng Chen
Keyword(s):  
Rapid Prototyping ◽  
Pipe Flow ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Rotor Design ◽  
Modern Engineering ◽  
Different Types ◽  
Computational Fluid Dynamics Cfd ◽  
Turbine Design ◽  
The Relationship

This study aims to research and develop Pipe Flow Generators. The focus in this paper is on the rotor design for pipes of different sizes. Modern engineering tools such as Computational Fluid Dynamics (CFD) software and Rapid Prototyping technology are utilized to facilitate the numerical and experimental studies. The CFD numerical simulations consist of two and three-dimensional transient and steady analyses. These simulations were conducted to find the relationship between the flow rate, blade geometry and number of blades. During the experimentation process, Rapid Prototyping Technology (RP) was used to fabricate many different types of turbine geometries to test different impeller parameters. RPM and voltages where measured for each turbine design. The study leads to several important findings for better pipe flow generators design.

Self-similar cylindrical expansion of impurity particles in a plasma

1994 ◽  
Vol 52 (3) ◽  
pp. 345-352 ◽  
Author(s):  
Ming Y. Yu ◽  
R. Bharuthram
Keyword(s):  
Cylindrical Geometry ◽  
The Self ◽  
Dust Particles ◽  
Charged Impurity ◽  
Physical Interest ◽  
Different Types ◽  
Fluid Theory ◽  
Self Similar ◽  
Similar Solutions

The radial self-similar expansion of negatively charged impurity or dust particles in a cylindrical geometry is investigated using the multi-fluid theory. Three different types of self-similar solutions are considered. Various asymptotic limits of physical interest in the self-similar space are shown to occur.

Measurement of Torque Moment of Aircraft Electric Drive Unit

2013 ◽  
Vol 486 ◽  
pp. 173-180
Author(s):  
Jindřich Rosa ◽  
Jan Cagáň
Keyword(s):  
Electric Drive ◽  
Test Stand ◽  
Strain Gages ◽  
Testing Laboratory ◽  
Drive Unit ◽  
Design Modification ◽  
Torque Moment ◽  
Ground Test ◽  
Power Testing ◽  
Small Airplanes

Aircraft Propeller Testing Laboratory of VZLÚ Praha-Letňany has taken part in a project called EPOS the development of an electric drive unit for small airplanes, with power up to 60 kW. The article describes preliminary phases of power testing of the complete propulsive unit in its first design modification on a ground test stand. The torque moment was measured using a special shaft element equipped with strain-gages.

Trust and inter-organizational networking

2000 ◽  
Vol 53 (10) ◽  
pp. 1287-1328 ◽  
Author(s):  
Susan Newell ◽  
Jacky Swan
Keyword(s):  
Interdisciplinary Research ◽  
Research Funding ◽  
Research Team ◽  
Research Network ◽  
General Question ◽  
Business Organizations ◽  
Major Research ◽  
Diverse Range ◽  
Effective Operation ◽  
Different Types

Inter-organizational and multi-functional networking are increasingly portrayed as new and potentially more effective forms of organization, especially where innovation is important. This is as true for academic work undertaken within universities as it is for business organizations; multi-disciplinary and inter-institutional collaboration being specified as highly desirable by the major research funding bodies. Integrating mechanisms are essential if such networks are to be effective in co-ordinating the work of a diverse range of partners. Importantly, they are required for the development of trust. Thus, the literature stresses that trust between the parties is central to the effective operation of such networks. This paper explores the evolution of trust within a particular inter-university, multi-disciplinary research team, and develops a model depicting the development and interrelation of different types of trust within this network. The difficulties this research network experienced in developing trust raise a more general question about the effectiveness of interdisciplinary research.

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