UGS NX7 Fluid structure interaction

[OmarMR]

Hello

I am starting to design a new gel dispenser and I want to simulate the fluid structure interaction between the dispenser and the gel. So I want to know if its possible to simulate this interaction in the NX7 and How I can made that??

Best regards

 

[jerry1423]

No, I do not believe that there is anyway that you can do it with NX - But if you have a mold flow software in-house (such as Flow3D) you may be able to utilize that to get what you are looking for.

 

[BlasMolero]

Dear OmarMR,
NX Nastran 7.0 (as being part of NX 7.0 Advancd Simulation) provides you with several different methods to analyze the effects of fluids upon a structure:
• NX Nastran contains an axisymmetric hydroelastic modeling capability that lets you solve a variety of fluid problems with small motion, compressibility, and gravity effects.
• NX Nastran allows you to compute virtual fluid mass.
• NX Nastran lets you perform a fully coupled fluid-structural analysis.
• NX Nastran lets you perform acoustic cavity modeling.

FLUID STRUCTURE INTERACTION (FSI)
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The above methods to model fluid effects in NX Nastran are described below.

• Hydroelastic Analysis:
Small motions of compressible or incompressible fluids coupled to a structure may be analyzed with this option. The fluid is modeled with axisymmetric hydroelastic elements (CFLUIDi), which may be connected to an arbitrary structure modeled with an axisymmetric wetted surface. Each fluid point (RINGFL) on a cross section defines the scalar pressure, which is expanded to a Fourier series around the circumference. Complex modes and frequency response solutions are available for the coupled fluid-structure problems. Normal modes solutions are available for fluid-only problems. All solutions may include gravity effects (i.e., sloshing) on a free surface. This capability was developed specifically to analyze liquid-fueled booster rockets but may also be useful for problems involving other types of axisymmetric storage tanks.

• Virtual Fluid Mass:
Small motions of incompressible fluids may be coupled directly to the structure with this option. Fluids may be coupled to the interior and exterior surfaces (with infinite fluid boundaries). There is no explicit fluid model; only the wetted structural elements (ELIST) have to be defined. Although free surfaces are allowed, no gravity effects are included directly. Since the fluid is represented by a coupled mass matrix attached directly to the structural points, this capability is allowed in all dynamic solution sequences. This capability may be used to model a wide variety of fluid-structure interaction problems. Some examples are fuel tanks, nuclear fluid containers, drilling platforms, and underwater devices.

• Coupled Acoustics:
You may analyze the dynamics of compressible fluids contained within arbitrarily shaped structures with the coupled fluid-structure method. You would model a three-dimensional fluid with conventional solid elements (CHEXA, etc.) using acoustic property and material data. Each grid point in the fluid defines the pressure at its location as its degree of freedom. The fluid is automatically connected to the structure via the geometry and ACMODL Bulk Data inputs. You can connect acoustic absorber elements (CHACAB) to the structural surfaces to simulate soundproofing material. In addition, the CAABSF element is now available. This element acts as a thin layer of acoustic absorbing material along the fluid-structure interface. Version 69 introduced several features, which are parallel to those available for structural analysis, such as direct damping, modal damping and the ability to control the modes in a response analysis through the use of parameter. You can define panels to provide integrated response data. Effects of gravity, large motions, and static pressures are ignored. Complex eigenvalues, frequency response, and transient response are the available solution sequences. Design sensitivity and optimization processes may reference the acoustic outputs as responses with appropriate design constraints. Applications for the coupled fluid-structure option are automotive and truck interiors, aircraft cabins, and acoustic devices, such as loudspeakers and microphones.

• Uncoupled Acoustics:
Several methods are available in NX Nastran for the analysis of normal modes of compressible fluids bounded by rigid containers and/or free surfaces. One method is the “acoustic cavity” capability, which uses two-dimensional slot elements and axisymmetric ring elements to define the fluid region. This method was specifically developed for the acoustic analysis of solid rocket motor cavities. A better method is to use the three-dimensional fluid elements for the “coupled acoustics” described above and provide the appropriate boundary conditions.

Please check NX NASTRAN User's Guide & NX NASTRAN Basic Dynamic Anlysis User's Guide, there you have plenty of information.

Best regards,
Blas.