Mr. Heinrich von Zadow

Hi Christina, you are looking at curves, not surfaces (both have a category "curve based"). On your screen it seems that surfaces are collapsed: If you are on a small screen this is probably fine. Otherwise, you can change the font size by pressing ctrl and scrolling the mouse wheel. Best regards, Heinrich

Hi Christina, if you are working with the latest (currently 5.0.6) version of CAESES, you should find lofted surfaces in the category of curve-based surfaces: I am not aware that this is excluded from non-commercial packages. apart from lofting you might want to take a look at sweep surfaces or, if non of the "standards" works for your application dig into the topic of meta surfaces. Cheers, Heinrich

Dear Christina, as mentioned in the other post, you can refer to the "freeformdeformationbulb" tutorial to get a very basic idea of how to apply a ffd to modify an existing bulbous bow. This is one (out of a much larger set) of the available morphing techniques that come with CAESES5. For a bulbous bow I can also definitely recommend to look into delta shifts and BRepMorphing. With these 3 you should have absolutely everything you need to modify an existing bulb geometry. For an optimization of a bulbous bow I would definitely recommend to include some variation of the forward shoulder (so you can achieve a favorable cancellation of waves) as well. Once you do that, you will probably also need to keep an eye on hydrostatics (check if the Lackenby suits your needs) to avoid shifting the LCB to much, or changing the displacement beyond what's feasible for your application. We have recently hosted a Webinar about morphing capabilities in CAESES5 which might be interesting for you ("How to Efficiently Optimize your Geometry with Morphing in CAESES 5") here: https://www.caeses.com/support/videos/ About the optimization, there are plenty of other tutorials and useful guidelines included in the documentation that should give you a good starting point. Hope this helps to get you started. Best regards, Heinrich

Dear Christina, the file Rull has posted further up seems to be very similar (if not identical) to the sample we ship with CAESES5. Just search for it in the help workspace (bottom left corner of the GUI) and you should find this: Best regards, Heinrich

Dear Atiyah, I recommend to start with the general documentation and then work your way forward through tutorials and samples. There is plenty of maritime-specific material on fully, as well as partially parametric hull-design available to get you started. Best regards, Heinrich

Dear Mr. Saeed, although I have no experience with such a design I am positive that something like this could be modelled with CAESES. Instead of the standard blade modeling functionality I would go for a meta surface to create the special shape. You could model the central u-turn-curve (dashed line in your last picture) first and then create the blade along this path while providing functions like chord, pitch, thickness etc. along this path. I guess, if you check the propeller and meta-surface tutorials and samples you should have a good idea how to proceed. Fell free to get back to me in case you get stuck. Cheers, Heinrich

Dear Chien, the position value is parametric. I modified the input surfaces for your blade such that now (0=start, 1=end and anything in between depends on the internal parametrization of your input surfaces, i.e. knot vector, control points, degree, etc...). Practically, in most cases you would need to know your leading edge position (now 0.5) and you can simply find out which side is suction and pressure by trial and error. I recommend that you move the hub seam out of the way (by adding 180° to the start and end of the hub contour). Also the trailing edge doesn't look ideal. I increased the tangent factors of the underlying fillet surface as a simple fix: Not sure if it makes a difference in this case, but please note, that I used the new 5.0.4 release. Unfortunately I couldn't get the variable fillet to work right away, either. I will try to find some time to take a closer look. Cheers, Heinrich propeller.cdbc

Here we go, thanks Paulo!

Dear Chien, why don't you upload yours? Probably even more helpful for you... Cheers, Heinrich

Dear Chien, yes, this is possible, although a bit tricky at times because you will need a very clean model to begin with... The result would look something like this: The corresponding settings here where as follows: Cheers, Heinrich

Hi Carsten, didn't know that, I guess this is new with CAESES 5 -- thanks for filling me in. Cheers, Heinrich

Hi Rohan, not directly. Best option would be two trimeshes "trimesh01" and "trimesh02" (one for each surface) and an imageCurve "c1" with the source "trimesh01.getShortestDistanceLine(trimesh02)". You can then create a parameter with "c1.getLength()" for the actual distance. Cheers, Heinrich

Hi Rull, I looked at your project and it works just fine -- see attached animation. I guess there will be some tweaking of the spacing and transformations of the points to get some really good shapes, but technically, it works. Did you make sure you look at the image surfaces and not the initial ones? Cheers, Heinrich

Hi Rull, I can not tell this from the picture alone. Did you set the FFD as a transformation (create and image surface from your existing bulb or assign it to a BRep if that's what you have). If you can't get it to work, feel free to attach your project here. Best regards, Heinrich

Dear Rohit, the design variables are used to describe/modify the functions given in 01_blade/functions. You can see how they affect their shape in 3D: You can find detailed information on their exact definitions in the documentations. To get there, just click the little blade icon next to the name of the blade: Best regards, Heinrich

Hi there, you might want to start by extracting the underlying surfaces of your BRep (create a BRepPart from it and then right-click > extract underlying surfaces) and take a look at them. If they are suitable (somewhat rectangular and nicely parameterized) you can get away with creating panel meshes from them directly. In my experience there will probably be at least a few regions which you have to re-model in order to get suitable patches for mesh generation. Cheers, Heinrich

Hi Zhen, just a small addition in case someone else stumbles across your question. For an actual (perfect) circle you can not use an F-Spline. Behind the scenes an F-Spline is a B-Spline curve, optimized with respect to fairness and constrained at start, end, start-tanget, end-tangent, curvature, enclosed area, etc... That means, if you set the area as the area of a circle and also match the tangent at start and end you will get something that is really close to a circle, but not a perfect circle. For an actual (quarter of a) circle, you need a NURBS curve with 3 control points. The weight of the center point needs to be set to 0.5*sqrt(2). In order to keep the area constant while moving points 1 and 3 (in your picture), I suggest a delta shift and a brent (you can search the forum for nested optimization to see how the brent algorithm can be used to adjust the area to a certain target value). Cheers, Heinrich

Hi Gunnar, very good. If you would like me to take a look at the mesh, feel free to upload it. Best regards, Heinrich

Hi Gunnar, You imported an STL file. Try using s STEP or IGES if you can. (These are not discretized, but NURBS-based) If you can get your hands on such a format, you can technically get to the underlying surfaces. However, they might be untrimmed and hence, not work for generation of your panelmesh. To check, create a BRepPart and use right-click "extract surfaces". If STL is all you can get, you don't want to put that in a BRep, but rather use Trimeshes and Solids. For trimeshes (maybe you can get one with higher resolution) you could try the right-click "split by angle". This should make quick work of the reparametrization of the individual faces. Best regards, Heinrich

Dear Rohit, if by download you mean export, you can simply select the geometry objects you would like to export and choose File>Export> and from there choose the format you need. See below screenshot for a list of available formats (depending on your license the list may vary): Best regards, Heinrich

Dear Zhen, in principle, yes. You could set up a second delta shift perpendicular to the first one and combine the two in a delta product. It would be way easier if you could just set up a fully parametric model. Or is there a specific reason why you need to start from an existing/imported trimesh? BR, Heinrich

Hi Zhen, in this case, I recommend using a simple delta shift. I renamed your curves: source (red), target(green) and calculated the y-offset between the two: "difference (black)". Now you can set up a delta shift to transform your source based on difference --> this will make it match exactly with target. Voila. Best regards, Heinrich test_bspline_HvZ.fdb

Dear Zhen, if you could attach your latest project file I am happy to take look. Best regards, Heinrich

Hi Armagan, firstly, from a CFD viewpoint I'd recommend you to go for a cylindrical domain, especially if you are going to split it into just a segment. I'd probably just create a domain-segment of 120° and then substract the wind turbine from it via boolean op. BR, Heinrich

Hi Rull, what you see when extracting surfaces from a solid ( it doesn't matter if it's a Parasolid import, or any other NURBS-based format, such as IGES, STEP or just a solid modeled in CAESES) are the "underlying surfaces". A few explaining words: BRep is actually short for "boundary representation" and gives you a hint about what's happening here. Underlying NURBS surfaces + a set of boundary curves (along with some other information) define the final shape. This is very convenient since it allows trimming (and cutting holes, etc.) without actually having to reparameterize the surfaces. If you "ectract" them, you will see the complete surfaces... I didn't quite understand you question/problem about removing this face though. Maybe you can explain it again? Best regards, Heinrich