Brodski vijak s promjenjivim usponom krila

Brodski vijak okretanjem radijalno raspoređenih krila pogonsku snagu stroja pretvara u porivnu silu, sastoji se od dva do sedam a najčešće od tri ili četiri krila. Većina brodskih vijaka imaju fiksna krila, ali postoje i vijci s promjenjivim usponom krila, te su upravo ti vijci tema ovog rada. Brodski vijak je rotirajuća struktura s krilima kojom se stvara porivna sila generirana od glavnog motora za vožnju broda naprijed i nazad. Porivna sila se stvara pretvorbom rotacijske sile od glavnog motora koja se prenosi preko odrivne osovine i reduktora do brodskog vijka, a rezultat je kretanje broda naprijed i nazad. Brod se kreće prema naprijed na osnovi Bernoulijeve jednadžbe i trečeg Newtonovog zakona. Razlika tlaka se stvori na prednjoj i krmenoj strani lopatica vijka što rezultira ubrzanjem vode iza lopatica, te pokretanjem broda.By spinning radially positioned blades boat propeller converts engine force to forward motion, it consists of two to seven but mostly out of three or four blades. Most of boat propellers have fixed blades, but there are also propellers with controlable pitch, and that type is main subject of this work. Ship's propelller is rotating structure with blades which creates impulse force from ship's main engine for mooving forward and aft. Impulse force is created by transforming rotational force from main engine over thrust shaft and reductor to ship's propeller, and the result is mooving of ship forward and aft. Ship is mooving forward on principle of Bernoulli's equation and Third Newton's law. Pressure deviation occur on front and aft side of propeller's blade, which results in a acceleration of water particles behind propeller blades, and mooving of the ship