propulsion

Hello all, I hope this thread is well placed here, if not, please let me know better one. I'm currently in the process of define the power requirement for a small catamaran (less than 5 m length), with an electric propulsion. Could someone share with me any information (formulae, estimation...

Hello everyone, I am struggling with one question considering small power boat design (up to 24m, planing hull) in concept and preliminary stage. That is how to estimate total propulsion efficiency when working on new design? I have found some average values around the internet but I am not...

Hi, I was curious to know what aspiring engineers and navigators thought about renewed forms of propulsion. Especially, Magnetohydrodynamics and Waterjet engines. I know that as of right now these propulsion systems are found in small vessels (ie tugboats). But, do you (in a general sense)...

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...

Hello there, As I'm working on Holtrop resistance prediction method, I would like to know how to find the Angle of entrance value. I have used the formula attached to the thread. In some cases, I get values like 58.6, 64.2 so n so. I wanted to ask if it's right or wrong. The length of run = 96%...

hi everyone I am doing research over the model testing facilities in india. i have few doubts regarding it 1.Use of wake test with help of wake rake i.e if the result is not as desired what should we change and what is then our aim to alter to get desired outcome or result of our test...

Dear all, I am trying to estimate the resistance added from a bulb on a sailing yacht in upright resistance. I have bare hull resistance calculated from maxsurf resistance I have calculated appendage added resistance with the methods described in the book "Aero-Hydrodynamics and the...

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?

Kind regards, happy boaters! I want to start a topic on wave force induced propulsion. Brief intro: I have been reading and enjoying this resourceful net place for a few decades ;-) It is fair and straightforward to say that www.boatdesign.net immense knowledge and experience have built up...

Hello everyone! I want to design a propulsion system for a tugboat with maximum performance on bollard pull using a ducted propeller (Kaplan). I already have the engine data that will be used for this project, but I don't know how can I develope numericaly this project. When I want...

We are looking for a Hydrodynamic Engineer who wants to sit in Orlando, FL. Must be able to obtain a security clearance (does not need to be active) For immediate response, please send resumes to ccrimmins@apexsystems.com Hydrodynamic Engineer Orlando, FL 32826 Salary/Pay is Flexible DOE...

Dear, I would like to know if any member of the forum could assist me (or guide, at least). I am looking for the points/coordinates of Kort No. 19A and 37. The materials where I found them were: 1. CARLTON, J. Marine Propeller and Propulsion (pages 114 ~ 117); 2. Principles of Naval...

Hi All, Can anyone advise how to do the powering calculation of a pusher tug. Pusher tug pushes -4 barges,each of 350 T capacity. Regards Adarsh

Not sure about the right place You can find a good information article here on waterjet propulsion . Learn about Waterjet Propulsion System - A Maritime industry Affairs https://www.worldmaritimeaffairs.com/learn-about-waterjet-propulsion-system/

Hi. Sooo its about 4 meters long catamaran boat with small electric motor propulsion. Hull (see attached picture below) is with aft tunnel to prevent air suction due to small draught and protect thruster from external "objects" and vice versa. The problem occurs when electric propulsion needs...

Hi, I am looking for a method to calculate resistance of a 40m vessel using the Van Oortmerssen (1971) procedure. Can anyone help with providing the paper or require empirical formulae? Thanks.

I have a 28' Hike Metal SAR boat with twin Volvo TAMD31's running Hamilton 211 jets through 1:1 Velvet Drive transmissions. The boat has an aluminum hull and the weight is listed as 3000 kg's. According to the shipper who delivered it the boat tipped 9000 lbs on the trailer so it's close to...

I'm planning a sailing (decent-performance cruising, not racing) catamaran, S/V Hypothetical. Construction is reinforced plastic, cored above waterline. Secondary propulsion will be gasoline outboards in wells. Hypothetical has a LOA of 12.99m (42.65'), LWL of 12.8m (42'), BOA of 7m (22.96')...

Dear everyone, I started working on sailing yacht concept, my first project. For the purpose of making the GA I need to decide about Propeller position, in longitudinal direction. I know that usually on smaller sailing yachts prop is saildrive or shaft type and postioned under stairs. Also...