# Research and Development at Nogrid

Computational Fluid Dynamics (CFD) is a branch of fluid mechanics and various types of numerical techniques and data structures used to study various problems. Fluid flow can be described by the conservation of mass, momentum, and energy, which are governed by coupled partial differential equations. CFD is applicable to a wide range of technical problems in different fields of natural sciences, environmental and aerospace engineering, biotechnology or industrial systems design. Computational Fluid Dynamics provides qualitative and quantitative results for fluid flow through numerical methods. mathematical models and software tools.

Nogrid software is a most modern technology based on a meshless method to solve the Navier-Stokes equations. It 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.

Our research and development programs listen carefully to our customers wishes, then respond with services and software that meet those needs. We understand that each customer's requirements are unique, and provide what is needed, when it is needed, on an individual basis. Nogrid develops new numerical tools and software to allow our customers to accurately and efficiently model complex systems and to study the behavior of liquids and solids over a variety of length scales and applications. Our research and development is divided into the following categories:

In engineering, fluid-structure coupling or **fluid-structure interaction** (**FSI**) refers to the consideration of the mutual influence of structure and flow. The mutual influence of structure and flow is an interesting phenomenon that often occurs in nature and technology. It occurs on deformable and/or movable structures around or through the fluid flows. The structure deforms under the forces imposed by the flow. In the case of highly deformable structures, the flow is very often disturbed by the structure and thus influenced. In this case, there is a real, two-sided fluid-structure coupling.

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. The software is a gridfree or meshfree method which, in contrast to classical numerical methods, such as Finite Elements or Finite Volumes, does not require a grid or mesh. The software can excellently be applied in the case of all problems, where grid-based methods reach their limits due to the necessary remeshing.

Our research group works on solutions for processes where the dynamic interaction between fluid flow and solid deformation is important and where deformable structures need special treatments in terms of physical properties and dimensions. Biology provides numerous examples of FSI where the structure is flexible and deformable and often very thin compared to the dimensions of the flow area.

Figure 1: Animation a 3D FSI case where small rigid spheres pass a water filter in a pipe