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1

Numerical investigation of the drag force reduction for homogeneous column of vehicles

Hamiga Władysław, Ciesielka Wojciech

New Trends in Production Engineering

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2019

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Vol. 2, Iss. 1

524--531

EN

This paper presents simulation studies on the aerodynamics of vehicles moving in an organized column. The object of research is a column that consist of three vehicles of the same type (homogeneous column). In this research geometry of Ford Transit was used. As a part of the studies, the air drag forces acting on individual vehicles were calculated. The results are presented in dimensionless drag coefficient. The influence of the distance between cars on the generated force was also determined. In the first stage of the work, a numerical model was developed based on the Ahmed body reference structure. The calculations were carried out for 9 different velocities. The obtained results of the drag coefficient were compared with the work of other authors. The applied turbulence model and parameters of the boundary layer were used to create a numerical model of a moving column of vehicles. Mesh independence for numerical model of van was verified. The Finite Volume Method was implemented in the ANSYS Fluent program and used for the calculations. The use of supercomputers was necessary due to the large size of the grid.

2

Modelling and simulation tests of a quadrocopter flying robot

Ciesielka Wojciech, Grzegorz Suchanek

New Trends in Production Engineering

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2019

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Vol. 2, Iss. 1

486--495

EN

In recent years, there has been a dynamic increase in the use of multirotor flying robots in various areas of economic and social life. Robots of this kind may be used in environmental research, after equipping them with an appropriate measuring systems. This includes taking measurements of various types of contaminants, such as: particulate matter (PM), various gases, noise and light pollution. To make this possible, it is necessary to conduct advanced model-simulation tests of the flying platform, analyse and determine the appropriate location for the measurement system. Most of the current research on methods and techniques of taking measurements on the flying platform does not take into account these issues. This work consists of two main parts: modeling and simulation tests, and experimental part carried out in laboratory conditions. As part of the work, quadrocopter dynamics equations have been developed and implemented in the Matlab/Simulink environment. The developed discrete mathematical model made it possible to simulate different robot maneuvers: upward, forward, sideways and rotation flight. In order to determine the required characteristics of the multicopter drive sets, a mobile dynamometer station was designed, constructed and programmed. The dynamometer allows, among others, to take measurements of thrust force, torque and rotational speed. The final stage of the work was the development of the numerical model and CFD calculations of the quadrocopter. In this part, distributions of the pressure fields and velocity for the robot's hover state were determined.

3

Analysis of the possibilities to improve the reliability of a 15 kV overhead line exposed to catastrophic icing in Poland

Gołaś Andrzej, Ciesielka Wojciech, Szopa Krystian, Zydroń Paweł, Bąchorek Wojciech, Benesz Mariusz, Kot Aleksander, Moskwa Szczepan

Eksploatacja i Niezawodność

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2019

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Vol. 21, no. 2

282--288

EN

The paper is a result of a synergic cooperation of two academic teams, i.e. power engineering and mechanical teams, and a distribution system operator. A real 15 kV overhead line exposed to a catastrophic load of ice and rime was analyzed and three solutions to improve the reliability of the tested object in such conditions were examined. Authors considered: shortening the length of the line spans, heating the main line with increased current and rebuilding the overhead line to a cable line. The researches worked out a FEM model taking into account the newest normatives, simulated the model, experimentally increased the load on the real line with measured wire temperature, and performed multi-variant calculations to determine indicators of reliability, i.e. SAIDI and SAIFI. The analyses were followed by conclusions thanks to which the reliability of power lines exposed to catastrophic icing could be increased. These inferences should be considered and applied by all distribution system operators in Poland.

PL

Praca jest efektem synergicznej współpracy dwóch zespołów akademickich: elektroenergetycznego i mechanicznego oraz operatora systemu dystrybucyjnego. Analizie poddano rzeczywistą, napowietrzną linię średniego napięcia 15 kV narażoną na katastrofalne obciążenia lodem i szadzią. Zbadano możliwość zastosowania trzech rozwiązań mogących poprawić niezawodność badanego obiektu w takich warunkach. Rozważono: skrócenie długości przęseł linii, podgrzewanie magistrali zwiększonym prądem roboczym oraz przebudowę linii do linii kablowej. W celu realizacji pracy wykonano badania modelowo-symulacyjne MES z uwzględnieniem najnowszych wytycznych normatywnych, zrealizowano eksperyment dociążenia linii wraz z pomiarem temperatury przewodów oraz przeprowadzono wielowariantowe obliczenia niezawodnościowe prowadzące do wyznaczenia wskaźników SAIDI i SAIFI. W wyniku szczegółowych analiz sprecyzowano wnioski końcowe pozwalające na zwiększenie niezawodności linii elektroenergetycznych narażonych na katastrofalne oblodzenie, które powinny być rozważone i stosowane przez wszystkich operatorów systemów dystrybucyjnych w Polsce.