Recent content by Alan Cattelliot

Sailor rescued clinging to upturned yacht off the Isle of Wight Sailor rescued clinging to upturned yacht off the Isle of Wight https://marineindustrynews.co.uk/sailor-rescued-clinging-to-upturned-yacht-off-the-isle-of-wight/ *** https://ducky.com.ua/classes/ducky16/

A trial with evidence against, so to say. Very interesting(surprising) to find in this report quasi all that has been already presented to the public. The whole history of the company and the fortunes of test models, to highlight the "toxic" behaviour of the founder. Some conclusions saying...

When IMO could be used instead of ISO, why not. If not, then ISO requirements shall apply.

Hi Andrew, What is indicated by TANSL is perfectly right, except : "zero heel and trim". This is not correct. People and mass onboard, whether actually tested or simulated, shall be at their rightfull place, in accordance with ISO 12217 definition : EN ISO 12217-1:2017 3.4.5 maximum load...

Here are a list of standard having requirements for HDPE boats • TURK polyethylene crafts • DNVGL-CP-0072 • AMSA NSCV PART C3 • IRCLASS Hull Structure of Thermoplastic boats • New Zealand Maritime Rules Part 40A • DNVGL-CP-0342 • KR Guidelines for Ships of Polyethylene

I also like practical things. It remembers me some much of the movie "Wind", with tank testing in the river and so on...

With a little more DIY spirit, you could also take exemple in G. Eiffel, that has (with his team of course) established a very famous catalogue of aérodynamique shapes, by throwing stuff from the top of his Eiffel tower and measuring flight Time... No mechanical Spring, no mechanics at all. A...

Then you could take inspiration in this kind of stuff : https://youtube.com/shorts/lDO_hC2gUnk?si=cdg1hGp1Yd6RN2GA Put smoke, blinking LED, do not forget a fancy look....put everything in it... Measure nothing with it...

One very important thing...Since you are simulating a moving sail, the apparent wind profile in height shall be twisted, in conjunction with TWA, TWS, and boat speed. To recreate this effect, I strongly recommend to get inspiration from the twisted flow tunnel, in Auckland. See the lames, with...

check displacement/scale of your model check Center of Gravity position check mass/unit of mass of your model check froud number of your model

It happens to me every time I dive into this standard ....

Check the applicable formulas (exemple for bottom structure, due to copyright, I cannot reproduce all the standard ) given in Table 12 —Design pressures for motor craft (kN/m2) / kAR = 0, so PBMD (Bottom Design Pressure) = PBM MIN. PBM MIN does not depends on kAR, so here is your Design...

kr is used to calculate kAR, which is "not to be taken <0 nor >1" (table 9. ISO 12215-5:2019 harmonised version). So, even is kr <0, kAR is limited and cannot be negative. Design pressures are then calculated as the maximum between : - Pressure having kAR in factor - Minimum pressure that...

Hi, Naca63012 or naca63015 are excellent for your application. Induced drag can be reduced if the section @root does not generate any lift. That means using a thinner (relative) profile @root will do. Keeping a 63xxx is a good idea, because that way, you can use thinner profile, but without...

Nice touch. Need a EC certification for your boat ? As representative of a notified body, and also a multihull´s lover, it would be a pleasure to help the boatyard go through this administrative procedure. Feel free to contact me via this website, or via the website IMCI.org cheers,