drag and resistance calculations in fastship or maxsurf

hi,
I have a rhino model of a hull. I was wondering if it is possible to do drag, resistance and stability calculations in either maxsurf or fastship. I have access to both the softwares but i have no experience in using them.
Also i am trying to find the drag for a donut shaped hull (basically a ring or tire tube shaped hull) I wanted to know if i import such a hull type in the above mentioned software will they work. I know its a very weird shaped boat i am talking about, so i want to know if i import this shape to maxsurf or fastship will these software give me accurate results or will it screw up somewhere. Does rhinomarine work in the same way?? or will it work for this donut boat i am talking about??

 

can somebody please help me with this???

 

Yes, you can import a Rhino hull into Maxsurf, save it as a Maxsurf file and then run it through Hullspeed to calculate resistance. Hullspeed has several methods covering different types of hulls (Savitsky planing; Savitsky pre-planing; Holtrop for slender hulls; van Oormeersen for short, full forms; series 60 for large ships) as well as a slender ship theory method for narrow vessels and multihulls.

Unfortunately Hullspeed does not have a method that covers donut shaped boats. It is unlikely that any of the above methods will give accurate results for the hullshape you evisage.

 

Briefly while one the subject, can hullspeed handle stepped hulls? Browsing the website I found nothing/

 

There is no direct method or evaluating the performance of stepped hulls within Hullspeed.

There may be a way of using the Savitsky planing method to get approximate results, however i have not investigated whether this is possible. You may wish to dod a Google search for Savitsky stepped hull and see if anything turns up.