Comparative Analysis of Propeller Characteristics on Aircraft in the CATC Fleet

Propeler je aerodinamička naprava koja energiju rotacije dobivenu od pogonskog motora pretvara u vučnu ili potisnu silu ovisno o izvedbi. Vučna ili potisna sila su približno okomite na ravninu rotacije propelera. Sam propeler sastoji se od dvije ili više lopatica odnosno krakova povezanih središnjom glavčinom koja pričvršćuje lopatice na osovinu motora. Ovaj završni rad općenito opisuje konstrukcijske izvedbe propelera, njihove geometrijske i kinematičke karakteristike te teorijske metode proračuna performansi propelera poput Froudeove teorije ili teorije elementa kraka. Analizirat će se propeleri u floti Hrvatskog zrakoplovnog nastavnog središta i usporedit će se njihove karakteristike i performanse pri različitim brzinama. Postoji nekoliko vrsta izvedbi propelera između kojih je glavna razlika mogućnost promjene kuta lopatica propelera u odnosu na struju zraka, tako da možemo izdvojiti propelere s fiksnim korakom, propelere s podesivim korakom, propelere s dvojnim korakom i propelere s upravljivim korakom.A propeller is an aerodynamic device that converts the rotational energy obtained from the drive motor into pulling or thrust force depending on the design. The pulling or pushing force is approximately perpendicular to the plane of rotation of the propeller. The propeller itself consists of two or more blades or arms connected by a central hub that attaches the blades to the engine shaft. This undergraduate paper generally describes the different designs of propellers, their geometric and aerodynamic characteristics, and theoretical methods for calculating propeller performance such as Froude's theory or blade element theory. The propellers in the fleet of the Croatian Aviation Training Center will be analyzed and their characteristics will be compared. There are several types of propeller designs, the main difference between which is the ability to change the angle of the propeller blades in relation to the air flow, so we can distinguish fixed-pitch propellers, ground-adjustable propellers, controllable-pitch propellers and constant-speed propellers