The most common question that many shipbuilders have when they see a well-made surface model of a ship's hull is "What program was this model made in?". Of course, the use of advanced programs that are well adapted to ship surface design is of great importance. At the same time, one should not forget that the program is only a tool, and the result depends on how well the designer feels the surface. It never occurs to anyone to ask a fashion designer - “What sewing machine is this dress sewn on?”.
“I want to study your program and design surfaces like you,” students who are starting to study ship design often write to me. How to explain that knowing how to use the program is not design yet? How can this be taught?
What is ship surface design? Art or craft? Do we need to talk about it at all? I specifically do not use the term modeling. Modeling is more about the mechanical repetition of a known idea than the creation of something new. It is not such a difficult task to make the surface of the hull with the given characteristics of displacement and center of magnitude. To make this surface technological, aesthetic and as smooth as possible is a completely different task. For me it's like art. A good designer, like a sculptor, feels the shape of the surface. This seemingly simple, but very exciting task - to remove all unnecessary and add the necessary. In order to learn this, you need to make a lot of ship's hulls. Only after that you will understand how the plasticity of the hull material correlates with the plasticity of the mathematical surfaces used.
The surface of the hull is like a monumental sculpture. All surface defects are visible on the real case. Whenever I see this, I feel a little sorry for the one who smoothed such a surface. And such a work of art, moving from port to port, demonstrates not only the flag of the owner, but also the quality and level of design.
A friend of mine once said: “Why try to smooth the hull if the shipyard assembly technology does not allow you to get a quality hull?”. I believe that with any case assembly technology, a high-quality case surface will only improve the final result. Errors in the surface, added to the errors in the assembly of the case, spoil it even more.
If you do the job quickly, everyone will forget it the next day. If done poorly, it will be remembered for a very long time. These words refer entirely to the ship's surface. Therefore, when I work with the surface, regardless of whether it is a barge or a superyacht, I try to use all the program tools to control the shape of the hull, including the lines of equal angles of the surface. This method is used to control the smoothing of car bodies. Perhaps this is too much, but given that the hull is smoothed out in a week, and several months are being built, I consider such costs justified. Shell plates fit better on such a surface, bending and welding processes are facilitated, gaps between parts and thermal deformations from welding are reduced. This benefits both the shipyard and the shipowner. Such ship's hull are less susceptible to corrosion and have less internal stresses. The hydrodynamic quality of such a hull is also higher.
The most interesting task in designing the hull surface is hydrodynamic optimization. Thanks to CFD methods, it became possible to provide high-quality visualization of the flow around the ship's hull. Now, looking at the wave surface, dynamic pressure distributions and streamlines, one can understand what needs to be improved in the surface in order to reduce resistance and improve the operation of the propulsion complex. This is an iterative process. Examining the results of the preliminary calculation, I change the shape of the hull so as to reduce the resistance and start the process again. Of course, there are many subtleties in this. To do this, you need experience. I will especially note that for more accurate calculations, the model that is used for calculations must be very well smoothed. Only in this case, the calculation results will correspond to the real process of flow around the body. So here, without sufficient experience, it is difficult to get a good result.
Summarizing all of the above, I want to emphasize that no matter how various automatic smoothing and hydrodynamic optimization programs are advertised, a practically acceptable result can be obtained only in the process of classical ship surface design.
The quality of design directly depends not only on what program the designer uses, but also on the constantly daily practice of designing ship surfaces. Therefore, I can advise all students who are starting to master this craft to constantly practice surface design and, preferably, do this on real projects. Even if you have received high-quality training in working with a particular program, you will not learn how to design a surface. To do this, you need to constantly practice your skills and doing this constantly. I do an average of 8-10 ship hull surfaces per month at various stages of design and optimization. Therefore, I can say for the heads of some companies that the idea to buy this or that program is not a solution to the problem of smoothing the surface, but only the beginning of its solution. For the correct use of programs, you also need a specialist who constantly practices in this matter.
A high-quality and optimal hull surface can only be obtained by working with a professional in this field. Working with various companies, I find the best options for cooperation, regardless of the types and sizes of ships being designed. At the same time, I guarantee not only the quality, but also the confidentiality of the information transmitted to us. I invite for cooperation not only new partners, but also students who really want to master this rather complicated art.
Thank you for your comment. My opinion is: "all in ship design and ship building must try to do the best, if we want to get best result".
Excellent article. Sometimes you see, for example, a perfectly smooth bulbous bow shape on your screen, but when you go to the shipyard workshop you say: what happened??? The plates were thick and could not be bent as they should or the time was not enough because of the schedule. I once heard someone say, "a ship is a ship and a clock is a clock", but both should aim for perfection. Success my friend.
by Solimar Sousa