propeller

Hello everyone, I'm currently in engineering school and we have to do a boat all by ourselves (a small one of course) and my group came to the discussion about propeller. Where do we place it to optimize water flow rate ? Our boat is 600mm in length, 97mm in height and the transom (back of the...

First, my assumptions: A. Boat is over-propped if it cannot reach rated RPM at WOT B. Boat is under-propped if it bests 105% rated RPM at WOT C. Towing a seine is basically pushing throttle against a brick wall/towing a massive sea-anchor against the current Second, where I’m coming from: A...

Hi I’m researching for my thesis on how to find the optimal propeller for an electrified version of a current boat. What I have: Hull resistance, weight, speeds of the vessel. My thoughts of process: I know the resistance of the boat, therefore I also know at least how much thrust I need...

Another attempt on making a propeller

This is a simple 4 blades propeller to print into 3D

After many attempt now I figure out how make a nice propeller with air foil section on the blades, and is very simple now for me the making of any kind of propeller shape. This is a simple 4 blades propeller to print into 3D

Years ago I presented Prelimina as free online tool to predict resistance of displacement boats. I forgot to post here that it also contains a calculator to predict propeller output for specified operating conditions and geometry characteristics. Implemented series of propellers: WB, Gawn, SPP...

Hello everyone, I have built a waterbike with foils and have tested it on the water, but my 16(diameter)*10(pitch) inches aircraft propeller seems to be very unefficient. My gear ratio is of 1/4. I am searching a new propeller with a greater pitch for my bike, and i wonder if somebody could...

Hi, I am new to boat design and really the science behind boating. I heard somewhere that on airplanes there is a certain RPM at which the propeller no longer creates thrust whether this is true or not I am not sure. If this is true I am wondering if there is some similar property on boat props...

What would be an ideal gear ratio for an 11 foot trimaran hull kayak using a dual 6 inch three blade counter rotating boat propeller set with a 1.16 pitch? I'm currently at a 1 : 13.33 ratio with a cog adjustable chain drive. Any ideas? I've got a range of reaching 1 : 18.75 gear ratio with the...

Hi, I would like to know how do you design a 3D propeller from 2D geometry,i.e. NACA profiles, blade sections?

hello it's my first threard in this side and I hope things will going alright so,I will begin by the keller criterion for the"CAVITATION" the K factor depend on the number of popeller,type of the vessel,they mention: k=0 for high speed twin screw k=0.1 for Twin screw k=0.2 for single screw to...

An impeller is a rotating part of a centrifugal pump which transfers energy from the motor that drives the pump to the fluid pumped by accelerating the fluid outwards from the center of rotation. A propeller is a device with a rotating hub, that when rotated, performs an action that is similar...

hello I am using the book of Dave Gerr to calculate a prop. But it is hard to read the diagram because i have a low Bp value (4,613). it's hard to read the correct number. i think it is 90 but i cant read the efficiency number and the pitch ratio number. Is there a better quality diagram or...

Good Evening. I am having problem deciding the specifications of my propeller, I have already obtained the curves for Resistance and Power vs speed. My ship has a Length of 91m, beam of 10.5m and a Draught of 4.5m. It is presently run using a 5 bladed 2.8m dia two in number propeller and with a...

Hi, I am interested in creating a database of different propellers on different applications and results. I have few magazines with some outboard test results in them. Can anybody suggest a publication(s) with extensive propeller test results. I am interested in the following: Displacement /...

Hey, I am looking for a propeller for our solar boat. But I don't know where to start calculating. I hope one of you can help me out.

Dear members, I have a huge doubt regarding the pitch determination in my project. I read in some materials that the pitch, by default, is determined at 70% of the thruster radius (0.7R). I also read that this pitch is also called Face Pitch or Nominal Pitch. I'm trying to design/generate the...

Hello, Aboard a tall ship we want to use our generators less and charge our batteries at night by means of the wind (thus extracting power from the shaft). We have a three blade propeller with a diameter of 1.5 [m], pitch of 0.92 [m] a J of 36.5 and a Fa/f of 56%. I assume its a Wageningen...

Hello Everyone, I need further explanation on the dimensionning of a propeller. My method is the following : Determine total resistance > assuming total resistance is equal to thrust > calculate Bu > find all coef etc ... But we always find Bp Delta diagram, but for calculating Bp we need...