beginners problems

[Mr. Steven van der Sluis 0]

Hello,

 

I have a few (beginners) problems. I have been making the tutorial of the fast monohull vessel. And in the process adding some of my own modifications. However I have a strange situation, though it does not cause a real problem.

 

I have defined the FOS, with forward intermediate point at x=60. When I create a metasurface, that extends from somewhere aft, to this x=60, Caeses actually creates it up to 59.908. Is this the way it should be? (the attached screenshots describe this problem)

 

Another thing, but this does cause a problem is that I am not able to extract a t value as start of the domain for creating an imagesurface (called srf_mid_trimmed). I created an image curve called CL_midsurface, which is the original length of the midsurface. And I try to get a t value using  CL_midsurface.ft(0,x position of the start of the domain). But this does not give me the correct start of the imagesurface.

 

I hope someone can help me with this.

hull2.fdbc

[Ceyhan Erdem 14]

Hi Steven,

 

Please check the attached project.

I have observed that, your function curve which is supposed to provide the x-position is not defined correctly. What the curve engine does is from the abcissa value (depending on your coordinate system) obtain the ordinate and provide this value as an input.

 

I have created a new function curve and got rid of the scale parameter.

 

Coming to your second question, when I use the command;

 

CL_midsurface.ft(0,20)   ; I assume 20 is the starting x-position

 

I obtain the correct value for position parameter which is 0.

 

Cheers

Ceyhan

hull2.fdbc

[Mr. Steven van der Sluis 0]

Hi Ceyhan,

 

Thank you for looking into this.

 

Regarding this scale, I feel kinda stupid. I had forgotten that problem already and the quick and dirty solution I used.

 

Regarding the second problem. I think I did not explain so clearly. It is not CL_midsurface.ft(0,20) I want to use. I need the t value for for a certain x position. This x position is the intersection of the top of the skeg with the FOB. Which should be at 22.5364. If I do CL_midsurface.ft(0,22.5364) I get a t of 0.0614. If I use this t-value in de srf_mid_trimmed domain, there is an overlap with the skeg. If I then determine the x of this srf_mid_trimmed, it is not at 22.5364 but at 22.4529. This x value on the CL_midsurface corresponds to a 0.05938 and not the previously determined and manually given as domain boundardy of 0.0614.

 

I have made an extra scope called "secondproblem" in which the info concerned is grouped.

 

grtz, Steven

 

*EDIT*

renamed the srf_mid_trimmed surface in my post, to avoid confusion and attached the proper hull3.fdbc

hull3.fdbc

[Mr. Steven van der Sluis 0]

Found it! The forward boundary was not in the intended X position, messing up my t value in the aft.

 

Sorry for the bother.

[Ceyhan Erdem 14]

Hi Steven,

 

Good to hear that you have resolved it.

Please let me know if you have further questions.

 

Cheers

Ceyhan