Keresés

Keresési eredmények

• Surface Quality of Carbide Metal After Electrical Discharge Machining

  31-38

  Straka Ľuboslav

  Kuchta Patrik

  Megtekintések száma:

  103

  Recently, the requirements for machining shape-complex products made of hard-to-machine materials, including carbide, have been increasing significantly. However, their machining is rather problematic. Additionally, a high-quality standard of the machined surface is generally required, not only in terms of roughness but also in terms of the geometric accuracy of the machined surface. All this while maintaining a high level of economy in the machining process. However, meeting these demanding requirements in real technical practice is not always an easy task. Moreover, in combination with modern machining processes, only a limited number of production technologies can meet this requirement. Therefore, due to the high demands placed on today's modern production and the required high standard of the machined surface, progressive EDM technology is increasingly finding its application. And it is through this progressive technology that it is possible to achieve relatively good success in carbide machining. The aim of this paper was therefore to describe in detail the results of an experimental investigation aimed at identifying the quality of the machined surface achieved in terms of the roughness parameters of the machined surface in the electrical discharge machining of selected types of carbides using a wire tool electrode.

• Analysis of Differences Between Levelling Networks in the County of Hajdú-Bihar

  84-92

  Varga Zsolt

  Kézi Csaba

  Czédli Herta

  Megtekintések száma:

  45

  The height determination of control and detail points is essential during the process of planning and manufacturing in the practice of civil engineering. Planning maps are drawn for the former, while the intended plan is set out on the ground during manufacturing, and after the manufacturing the completed installation is mapped. Using the same reference system in all three steps, both horizontally and vertically, is recommended even though in some cases it is unavoidable to change from one reference level to another. Regardless of the fact that both refer to the mean sea level of the Baltic Sea, this can create difficulties, since the difference between the EOMA and Bendefy networks used in Hungary shows varying values depending on the geographical location. The aim of the analysis is to determine a constant difference regarding the analysed settlements based on the common points of the networks.

• Zöld infrastruktúra alkalmazásával elérhető vízminőség javulás mértékének becslése Debrecen példáján

  34-41

  Hancz Gabriella

  Biró János

  Megtekintések száma:

  174

  A települési zöld infrastruktúra megoldásai javítják a felszíni- és felszín alatti vizek minőségét és a vízháztartást. A tanulmány célja becsléssel meghatározni, hogy az utak mentén alkalmazott települési zöld infrastruktúra megoldások milyen mértékű vízminőség javulást eredményezhetnek. Ez magas prioritást élvez az ivóvízbázis védelmi területeken, ahol az utakról lefolyó szennyezett csapadékvíz beszivárgással elérheti az ivóvízkészletet. A becslés első lépésében a vízbázis-védelmi területen lévő belterületi közutak felületét határozzuk meg térinformatikai módszerrel, majd az itt felhalmozódó jellemző szennyezőanyagok mennyiségét, végül a lefolyó csapadékvízből eltávolított szennyezőanyag mennyiségét határozzuk meg zöld infrastruktúra megoldásokat feltételezve. A végső cél az ivóvízkészletek védettségének növelése.

• Evaluating the Efficiency of Polyhedral Mesh Elements in Solving the Problem of the Flow around Ship’s Rudder

  241-256

  Ibraheem Amjd

  Megtekintések száma:

  203

  Meshing is one of the crucial key features to the success of CFD based simulations, this study is evaluating the efficiency of polyhedral elements in solving the problem of the flow around ship rudder, using a Reynolds-averaged Navier-Stokes turbulence model (SST k-ω), and compares it to a tetrahedral based mesh, considering that polyhedral elements were neglected in the past due to difficulties in implementing them, this was solved by introducing a tool by ANSYS that converges tetrahedral elements to polyhedral element, and integrating it into FLUENT software, the model was validated by comparing it with previously validated model which used the full version of ANSYS, this study was concluded using the academic version, but still it was able to produce satisfying results in predicting the lift and the drag coefficient, the pressure around the rudder surface, the velocity and the turbulent kinetic energy, finally the mesh quality was evaluated using the orthogonal quality criteria, the results showed the supremacy of the polyhedral elements in saving time and computational resources and improving mesh quality, and keeping high level of accuracy in predicting the results.