Oblikovanje srpastih lopatica aksijalnog ventilatora

undergraduate thesis

• Title (english): Design of sickle blades of axial flow fan
• Author: Petar Filipović
• Mentor: Željko Tuković (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2016-03-01, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U ovom radu je izrađen računalni program za oblikovanje srpastih lopatica aksijalnog ventilatora. Pretpostavljeno je da profil lopatice od korijena do vrha ima oblik kružnog luka, te je za matematički opis strujanja oko takvog profila odabrana tzv. Weinig-ova metoda. Kod te metode se potencijalno strujanja kroz turbinsku rešetku sastavljene od kružnih lukova opisuje primjenom metode konformnog preslikavanja. Da bi se osiguralo uspješno oblikovanje lopatice i za aksijalne ventilatore kod kojih, zbog nepovoljnog odnosa između vanjskog i unutarnjeg promjera nije moguće osigurati radijalnu ravnotežu na izlazu iz rotora, uvedena je mogućnost definiranja zakonitosti promjene aksijalne brzine fluida i specifične predane energije od korijena do vrha lopatice koje odstupaju od uobičajenih zakonitosti. Srpasti oblik lopatice određen je oblikom srednje linije lopatice. Definiran je parametarski oblik srednje linije kod kojeg se prikladnim odabirom parametara oblik linije može mijenjati od ravnog do uvijenog u smjeru rotacije. Na kraju definiran je postupak oblikovanja lopatice tako da se ravni profili dobiveni primjenom Weinig-ove metode slažu uzduž srednje linije lopatice te se vrši njihovo mapiranje na odgovarajuću cilindričnu površinu. Na kraju rada je dan primjer proračuna s prikazom dobivene lopatice.

Abstract (english)

In this work, a computer program for design of sickle blades of an axial fan is developed. It is assumed that blade profile from a hub to a shroud has a shape of a circular arc and for mathematical analysis of a flow around this type of a profile the Weinig’s method is applied. In this method, potential flow through a cascade of blades is analysed with the conformal transformation method. In order to ensure successful development of a blade for an axial fan, which has an unfavourable ratio of shroud and hub radius, for which it is not possible to achieve radial equilibrium at the outlet of a rotor, principles of change for an axial component of the velocity and specific energy is introduced which deviates from standard principles. Sickle shape of a blade is defined by the form of a mean line. One parametric mean line form is defined wherein changing parameters cause the mean line to change from a simple straight profile to a profile which is curved in the direction of rotation. At the end straight profiles calculated by a Weinig’s method are distributed along blade mean line and mapping on cylindrical surface is done. At the end of a paper example of calculation with the figure of calculated blade is given.

• Keywords: aksijalni ventilator; srpaste lopatice; konformno preslikavanje; Weinig-ova metoda; profiliranje lopatica
• Keywords (english): axial fan; sickle blades; conformal transformation; Weinig’s method; design of blades
• Language: croatian
• URN:NBN: urn:nbn:hr:235:906670
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 16:22:36