Keel Design improvements

Hi,
I am a student who is conducting research on the dorsal fin designs of dolphins in order to incorporate their designs to boat keel designs . I'm currently mentored by Dr. Frank Fish of West Chester University and have gathered original data from dorsal fin samples. Currently, I'm looking towards the second step of my research and hoping for guidance on the possible paths I can take.

I have taken mainly physical measurements (chord length, maximum thickness, distance between leading-edge and max thickness ) as well as ratios like fineness ratios of the fins at different points along its height. Do you guys what possible modifications could be made to conventional keel designs that would help in helping to make tighter turns (or any other functions)?

Any help would be greatly appreciated, thank you.

 

roxlip

If you're doing pure research, then once you ahve all your data on dorsal fins, you should be able to perform a parametric study to ascertain if there is a 'trend'. Once that has been done, you can compare against exists designs. Finally after comparing against existing designs, you can then modify existing designs to estimate any changes in performance, owing to previous database research of your parametric study.

Until you have established whether there is a correlation of some parameter that affects performance of the dorsal fin and the dolphins ability to do "what ever your looking at" and a yatch to "making tighter turns", it is pure speculation. You need to establish some factual evidence to see whether it is worth debating further.

However, from memory this type of research has been done before, a friend of mine at uni also did something very similar over 20 years ago. It may be worth seraching for similar first, saves going over 'old ground' and also may assist your own research.

 

Yes this type of research is not new-- it has been done with fluke and pectoral fin designs, but new with dorsal fin (which is what I'm doing).

the trouble with this that I'm having is that I cannot find similar information on the keel geometries. Also, it seems like much of the difference in performance between dolphins and boats is in the material (flexible in dolphins, rigid in boats). However, this is not somthing you can 'compare' by simply researching online.

 

You should search for articles on windsurf boards and their fins.

 

Do you think a dorsal fin performs the same function as a sailboat keel?

Do you think anyone wants to "make tighter turns" in a sailboat? If so, do you think the keel shape is the limiter?

I think you and your Dr. Fish need to look at the real questions before moving forward looking for some answer.

 

roxlip

With your own database of dorsal fin data, you can establish your own trend. From this, extrapolate into a "theory" for a rough rule of thumb for comparisons. For example, you may find that dorsal fins which have a percentage area of say 5% compared to the total area (profile) of the dolphin enables these dolphins to turn at a greater rate (of course you'll need to establish more than just dorsal fin geometry to have anything meaningful otherwise you are just measuring fins!). This type of sensitivity analysis will yield very useful results, without the need to understand material properties and many other undefined parameters etc, since that type, is real serious research which would cost squillions and take eons...worth doing, but a life times research project!

 

What drove you to compare a dorsal fin, made of meat, with a keel made of lead?