Gene-Hull Sailboat 3.0

I am pleased to propose you this new ugraded version of Gene-Hull application for Sailboat. This upgrade 3.0 includes mostly the following improvements :

• the « E » sections formulation (E for Elliptical like) is generalised and the combination VE can now cover all kind of shapes from classic V to modern U ones.
• The « V » sections formulation is itself extended and can now includes tumblehome shape if required,
• The bow profile and its fore foot can be fine tuned thanks to a new parameter « Kbrion » in addition to « Cet » one.
• The scow bow possible shapes are broader thanks to a new parameter « PuiScow » in addition to « Scow » one.
• 3 types of keel are proposed : inverted L, inverted T, fin keel of high or low aspect ratio without bulb.
• 2 types of rudder are proposed : suspended (1 or twin rudders), with a skeg
• the stability study can be done with a specified loading and for any heel angle up to 180° , allowing to build the complete Gz curve and to identify the angle of vanishing stability AVS.
• A specific sheet « Offsets x,y,z » is proposed , where all the geometrical output data are gathered and can be copy/paste for a transfer towards software tools oriented for engineering studies or 3D renderings.

It is a free and open source speadsheet application, developed on a support itself free and widespread (Open Office Calc 4.0.1) : to open and use an ods file, you need either Open Office or Libre office on your PC, if necessary to download according to : ODS File Extension - What is an ods file and how do I open an ods file? | OpenTheFile http://www.openthefile.net/extension/ods

Also attached are :

• The User Guide giving all definition and information on the role and influence of each input data with illustrations + examples and explanations about the output data.
• Examples, i.e. 17 sailboats early stage projects covering a broad range of typical designs, classic and modern. For the first one named V1, steps of the loop design which can be done with Gene-Hull are detailed : Hull and appendages definition, Sailplan definition, Preliminary mass spreadsheet, Stability study of the heeled sailboat with its payload. The input data for V1 are in place in the « Gene-Hull » sheet of the file, the input data of all 17 examples are also on the « Hulls storage » sheet and can be copy/paste .
• The formulations involved for the hull generation, including the intermediate coefficients and numerical examples for checks.

The interface format and most of the input data are identical to the previous versions, so you should easily jump in this new version with your previous results.

For the beginner : it is recommended to first test the influence of each adimensional parameters, without changing the geometrical data, to see and learn about the influence of each one, in conjunction with the explanations given in the User Guide.

For the more advanced user : you can take advantage of one of the 17 examples showed in the « Examples » document, of which input data are stored in the « Hulls storage » sheet , to start a new project.

By hoping this new version can be helpful for your early stage projects. Under construction are 2 post applications , a VPP one , a STIX one, in line with the data provided by Gene-Hull, in order to add 2 more steps to the loop design.

Thank you Dolfiman.
Your Gene-Hull is extremely powerful as a design tool and becoming increasingly so. The contribution you have made to the thorough analysis and understanding of the Corbin 39 would in all likelihood not have been possible without using Gene Hull.
regards, David/pb

Thanks David for your kind words, it has been instructive as well as a pleasure to collaborate with you on the Corbin 39 analysis, and moreover stimulating new developments for Gene-Hull ending up with this 3.0 version.

I have just downloaded Gene-Hull Sailboat 3.0.
What you have done is impressive.
One question just to be sure I understood correctly:
To compute the full GZ curve you have to do it manually by changing iteratively the values of height and trim until the two displacements are equal and Xc =Xg?
Regards, Erwan

Thanks Air De and yes, you understand correctly. I know that the process to do a complete GZ curve from 0° to 180° with a step of 5° is quite long to do due to the manual iterations for each equilibrium. So I am developing a specific file "Gene-Hull Sailboat-Stab" whithin which the iterations are performed automatically for each given heel angle : it takes now about 10-15 mn to do the complete Gz curve with step 5°. It works but I have not finished all the checks and to write the user guide. I can give you attached the preliminary version with boat V1 data in place, you can input the heel angles in cell B163.

Excellent. I am going to try it.
Actually before I wrote my post yesterday I "played" a bit with your spreadsheet and thought that I could try to create a macro to make the computation of the GZ curve automatic but now I see that you are working on this. That's perfect

Here is the promised stability module :
Gene-Hull Sailboat_Stab 1,0 is a specific file dedicated to the stability issue of a sailboat project generated with « Gene-Hull Sailboat 3,1». It makes possible the computation of the GZ curve up to 180° of heel angle and provides information which are deduced, mostly :
- the angle of vanishing stability AVS,
- the stability index STIX,
- the positive / negative areas ratio under the GZ curve,
- the influence of another Zcg position on these results.

Why a specific module on stability ?
« Gene-Hull Sailboat 3,1 » already provides a stability subroutine which allows the computation of the GZ curve but through manual iterations up to an equilibrium for each heel angle, which makes the construction of the GZ curve very long and laborious to do. In «_Stab», the computation of the equilibrium for each heel angle is done automatically, so that the construction of the GZ curve, from 0° to 180° with a step of 5°, takes only about 10 minutes instead of about 6 h before. The file is not attached as an extra sheet to the Gene-Hull Sailboat file because it would be a too big and complex spreadsheet application to deal with. So it is proposed as a specific file with using the data coming from Gene-Hull Sailboat through an easy copy/paste process explained in the User guide. Moreover, it provides a sheet dedicated to the computation of the STIX index.

Together with « SA-VPP », another detached application using « Gene-Hull Sailboat » data, « _Stab » is an extra tool which completes the toolbox of spreadsheet applications to design and optimise a sailboat project at its early stage.

It is a free and open source speadsheet application, developed on a support itself free and widespread (Open Office Calc, version ≥ 4.0.1) : to open and use an ods file, you have to download Open Office or Libre office according to : http://www.openthefile.net/extension/ods

Also attached are the User Guide, an Examples document of input/output data for 4 different sailboats and, as a remind, the « Gene-Hull Sailboat 3.1 » spreadsheet application itself. 3.1 is the last version which, from 3.0, includes in complement the data preparation for SA-VPP, as described in : [URL='https://www.boatdesign.net/threads/sa-vpp-sailboat-a-free-application-for-speed-prediction.64582/']"SA-VPP Sailboat", a free application for speed prediction | Boat Design Net

By hoping this can be helpful for your project, and Merry Christmas to everyone.[/URL]