FAQ (Frequently Asked Questions)
1. What is NOGRID points?
NOGRID points, based on FPM (Finite Pointset Method), is a meshless CFD software package for simulation tasks in the wide area of flow and continuum mechanical problems. NOGRID points is a grid-free method which, in contrast to classical numerical methods, such as Finite Elements or Finite Volumes, does not require a grid or mesh. NOGRID points can excellently be applied in the case of all problems, where grid-based methods reach their limits due to the necessary remeshing. Examples are fluid dynamical problems with free surfaces, multiphase flows, fluid-structure interactions with a strong change of the computing domain, or structure mechanical problems with substantial structure changes.
2. Do I need 3rd-party software?
No, all tools which are required to run a fluid mechanics simulation case are provided and supported by us. So our software package includes the NOGRID points solver, the NOGRID points Graphical User Interface (GUI) and our CAD system COMPASS as preprocessor. With these tools you are able to generate all sorts of CFD models. In addition you are able to import CAD models from any other CAD system into COMPASS via the STEP or IGES interface. COMPASS automatically generates 2D surfaces meshes for 3D computations and 1D line meshes for 2D computations. These meshes are only required for the representation of borders/walls of the model. The point cloud inside the flow domain is generated automatically during the computation depending on user specification.
3. Which operating system can we use?
All software components are running on Linux (32bit/64bit) and Windows (32bit/64bit)
4. What about NOGRID points features list?
For more details about the NOGRID points specification see here.
5. Is there any literature or are there references about NOGRID points and the method behind?
We collected some references regarding the method, the theory and some applications here. Some copies are available at NOGRID GmbH. Do not hesitate to contact us.
6. Is it possible to compute a model with a large number of particles (such as 1 million, or even over 10 millions)?
Yes, it is possible. It's only a question of memory. The number of numerical iterations to find a solution increases slightly disproportionate to the number of points. Thus the computation time increases also slightly disproportionate to the number of points, for instance:
100.000 points = 1h computation time
1.000.000 points = 13 h computation time
But this depends strongly on the application and on the selected solver.
7. What is the typical number of time steps required?
This depends on the application. The global time step size is given by the smallest time step in the system:
dt = point distance / fluid velocity in case of Lagrange
dt = point distance/ free surface velocity in case of Euler
dt = point distance/ moving part velocity in case of Euler
8. What about the typical computation time in comparison to the FE-method?
The computation time strongly depends on the CFD model and on the accuracy of the results. Thus a general statement is difficult to give but our experience is as follows: The computation time for applications including free surfaces or moving parts is 1 to 10 times faster than FEM (especially in 3D) and for applications without moving parts and without free surfaces it is 1 to 2 times slower than FE-methods.
9. What about the memory requirement?
NOGRID points runs on each usual PC/workstation. A model with one million points requires about 2-3 GB RAM memory.
10. Are there any turbulence models such as RANS, LES, etc. available?
We currently do not provide any turbulence model, but implementing a ke-model is one important item in our development plan and we try to provide such a model as fast as possible.
11. What about the capability of solving steady flow or transient flow?
For steady flows one can use the EULER-method and for transient flow the LAGRANGE method is often the best choice.
12. Is NOGRID points an implicit or an explicit solver?
Both. The implicit solver is used for the incompressible part of the code. The explicit solver is used for the compressible part of the code. The compressible part is currently available only as Add-on (not included in the standard package).
13. Which physical phenomena can be modeled?
A lot of physical phenomena can be computed by NOGRID points: The Johnson-Cook model for viscoelastic materials, the Bird-Carreau model, the Power law model, the WLF model, WLF-Carreau-Yasuda, the Herschell-Bulkley model, VFT (Vogel-Fulcher-Tamman), user defined viscoelastic models, user defined viscoplastic models, user defined plastic models, linear elastic models.
1. What is NOGRID pointsBlow?
NOGRID pointsBlow is a forming simulation software that was developed especially for the container glass industry. NOGRID pointsBlow uses the same solver as NOGRID points and is able to simulate the glass container forming process in complete 3D.
2. Which data/parameter do I need for a simulation with NOGRID pointsBlow?
You need the geometry of your bottle (imported from your CAD system), material- and process data.
3. How long does a simulation of one bottle take?
This depends on if you choose a 2D or 3D computation. A computation of an axis-symmetric bottle in 2D does only take a few minutes. 3D computations range between 1/2 hour and 8 hours.
4. Why should I use NOGRID pointsBlow ?
NOGRID pointsBlow helps to understand the process of container glass forming and the way the glass flows. You receive very valuable advantages: You can increase the quality of your products and decrease your costs on the long run. You'll save time and resources.
5. Is NOGRID pointsBlow able to simulate all kinds of bottles, even strange shapes?
Yes, every 3D shape, even bottles with a handle can be computed.
6. Can only axis-symmetric bottles be computed?
No, any shape can be computed, even non-axis-symmetric bottles, as for example perfume bottles.
7. Which kind of container glass forming processes can be simulated?
NOGRID pointsBlow is able to simulate the following container glass forming processes: BB, PB, NNPB and PB for tableware.
8. What about the blank mould design - can the design/geometry be computed automatically?
Yes, you can compute the blank mould design with NOGRID pointsBlow either manually or automatically.
9. Which are the advantages of NOGRID pointsBlow in comparison with other simulation software?
There isn't any comparable simulation software in the global market that can simulate the process of container glass forming and show the results in 3D. NOGRID pointsBlow is the only software worldwide that is able to compute this process in 3D.
10. Can I simulate the whole container glass forming process in the IS machine? Is every step visible?
Yes, all process steps are integrated in one model - from gob loading until take out.
11. Do I need a special CAD system for the use of NOGRID pointsBlow?
The geometry of your bottle can be imported from each CAD system directly into NOGRID pointsBlow.
12. Which is the best way to learn how to use NOGRID pointsBlow ?
Within a training you will learn how to use NOGRID pointsBlow. There is also the possibility to create a project in order to develop all models and data required.
1. What is COMPASS?
NOGRID's COMPASS is a 2D/3D CAD system developed by NOGRID as preprocessor for the NOGRID CFD solver. COMPASS is based on the Open CASCADE Technology and it includes components for 2D and 3D surface and solid modelling, visualization, data exchange and rapid application development.
2. What about reading models from other CAD systems?
There are two possible steps to read/import a CAD geometry:
a) Import a step/iges file from any other CAD software into COMPASS and give the faces a name and save everything. That's all.
b) Some of our customers need direct CAD import. Depending on the CAD system the User must be able to name all walls within their CAD system and export the geometry including the group names into a STEP file. So this STEP file contains all walls including its names. Now the User can import that STEP file into the GUI and generate a mesh file or he can run COMPASS within a batch script and the meshing is done in the background.
3. What kind of 3D model data can COMPASS read?
COMPASS reads files in STEP format or IGES format.
4. Does COMPASS require topologically closed "clean" surface data representing analysis region boundaries?
No. If the distance between the edges of two faces (two faces which are usually connected by one edge) is less than the smoothing length (point density), this small gap is ignored. Thus small gaps due to not cleaned surface data are allowed.
Licensing and Support
1. How much is the license cost for a year?
The price for a one year license depends on the software and the services selected. A one year NOGRID points/NOGRID pointsBlow license includes support and maintenance.
One (1) NOGRID points/NOGRID pointsBlow license means one (1) active process at the same time. NOGRID points/NOGRID pointsBlow include the NOGRID points solver software, the NOGRID points/NOGRID pointsBlow GUI and the COMPASS CAD software as preprocessor. As postprocessor we use the open source software Paraview. NOGRID points, NOGRID pointsBlow and COMPASS are trademarks of NOGRID GmbH. Please contact us directly for a price information.
2. Do you offer evaluation licenses?
To perform studies we offer special evaluation licenses (usually for 1 month), together with a two-days-training (liable to pay). The training course can start immediately - depending on your schedule book. If you need a training at your location we can visit you of course, then additional costs/fees will arise. For starting to work with our software it is always a good idea to make a first project together. In that case you define the tasks you would like to be solved and we perform the complete computations for you. If everything works fine, you can get all project files and you can run your confidential NOGRID points-tasks at your office with all well known and adjusted settings.
3. What kind of license system do you use?
The license manager must be installed on a server and provides the licenses to the clients. Thus we are using floating licenses. The clients can be each usual PC/workstations or cluster and a network connection between the server and the clients must be available.
4. What kind of support can we get?
The support is provided by email or by phone.
5. How long does it take to use your software when we decide to buy a one-year-license?
After having received your order and after payment you can download the software from our website immediately. The license file will be sent separately by email.
We hope that this information has been helpful to you. Are you interested in additional information about our CFD software and our services? Please let us know what we can do for you.