Periodica Polytechnica archív cikkek
http://hdl.handle.net/10890/15594
A Periodca Polytechnika folyóiratok korábban a BME PA-ban tárolt cikkei. Nem teljes archívum, csak egyes cikkeket tartalmaz.2021-09-28T20:41:23ZDerivation of Equations for Conductor and Sag Curves of an Overhead Line Based on a Given Catenary Constant
http://hdl.handle.net/10890/5232
Derivation of Equations for Conductor and Sag Curves of an Overhead Line Based on a Given Catenary Constant
Hatibovic, Alen
When the spans of an overhead line are large (for instance over 400 metres) the conductor curve cannot be considered as a parabola, since in that case the difference in comparison to the catenary cannot be neglected. At such times the exact calculation has to be applied, i.e. the conductor curve has to be considered as a catenary (hyperbolic cosine). The catenary based calculation does not have limitations, it can be used for small and large spans as well, but in comparison to the parabola method it is significantly more complicated. This article shows the way of derivation of new equations for the conductor and sag curves based on a known catenary constant, which refers to the chosen conductor type, span length, tension and temperature of the overhead line. The shown formulas ensure exact computing of the conductor height and sag at any point of the span, avoiding errors generated by the approximation of the catenary by a parabola.
2014-01-01T00:00:00ZLDV measurements of Newtonian and non-Newtonian open-surface swirling flow in a hydrodynamic mixer
http://hdl.handle.net/10890/5186
LDV measurements of Newtonian and non-Newtonian open-surface swirling flow in a hydrodynamic mixer
Csizmadia, Péter; Hős, Csaba János
The aim of this paper is to study the cyclone-like flow inside a hydrodynamic mixer experimentally, with a special emphasis on the differences in the flow field in the case of Newtonian and non-Newtonian fluids. The mixer consists a cylindrical body with conical bottom, in which two, tangentially entering fluid jets drive the rotating motion of the fluid body. The two fluids are (1) water and (2) a Carbopol solution obeying power-law rheology. The circumferential and axial velocity distributions were measured with the help of LDV for several fluid levels and driving flow rates. We show that in the case of water, the velocity distributions are qualitatively similar for several flow rates if the fluid height is kept constant. In the case of the power-law fluid, the measured velocity profiles show less generality.
2013-01-01T00:00:00ZCorner Detection and Classification of Simple Objects in Low-Depth Resolution Range Images
http://hdl.handle.net/10890/5061
Corner Detection and Classification of Simple Objects in Low-Depth Resolution Range Images
Kovács, Viktor; Tevesz, Gábor
This paper deals with corner detection of simple geometric objects in quantized range images. Low depth resolution and noise introduce challenges in edge and corner detection. Corner detection and classification is based on layer by layer depth data extraction and morphologic operations. Appearance based heuristics are applied to identify different corner types defined in this paper. Both computer generated and captured range images are dealt with. Synthetic range images have arbitrary range resolution while captured images are based on the sensor used. Real world data is collected using a structured light based sensor to provide dense range map.
2013-01-01T00:00:00ZNonholonomic Path Planning for a Point Robot with Car-Like Kinematics
http://hdl.handle.net/10890/5026
Nonholonomic Path Planning for a Point Robot with Car-Like Kinematics
Kiss, Domokos; Tevesz, Gábor
A new approach of nonholonomic path planning for car-like robots is presented. The main idea is similar to many existing approaches which obtain a path in two phases. It is familiar in nonholonomic planning that at first a holonomic path is planned which is approximated by a nonholonomic one in a second step by subdividing it into smaller parts and replacing them with local paths fulfilling the kinematic constraints. These methods mostly rely on probabilistic methods and heuristic optimization. Our approach uses a holonomic preliminary path as well, but it serves only as a "loose guidance" to the second phase of the planning process. The final path is not required to contain any of the intermediate points of the preliminary path at all. The method is effective in environments consisting of narrow corridors but having wider free areas as well which can be used for maneuvering.
2013-01-01T00:00:00Z