CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   Main CFD Forum (https://www.cfd-online.com/Forums/main/)
-   -   fluid/structure interactions (https://www.cfd-online.com/Forums/main/8492-fluid-structure-interactions.html)

John December 28, 2004 09:19

fluid/structure interactions
 
I am looking for some kind of idea as to what kinds of the fundamental fluid mechanics have to be modelled in order to achieve accurate results for fluid or structural interactions, and what kind of mathmatical model could be used to represent the physical system.

Peter Attar December 28, 2004 13:12

Re: fluid/structure interactions
 
Iou will have to be more specific..for example I have computed excellent results for aeroelastic simulations using simple vortex lattice theory in combination with a nonlinear structural model. However these were low Mach number, high Reynolds number flows. The type of fluid model you will need will be a function of several factors including the Mach number,RE number and the magnitude of the structural deflections. Also you need to consider what type of structural modelling will be needed and whether you can use linear models or whether you will need to use nonlinear(geometric or material or both) models.

Peter

Mani December 28, 2004 16:18

Re: fluid/structure interactions
 
As Peter pointed out, there is really no answer to your question unless you are more specific.

However, as a general guideline:

1. The type of flow you are looking at will determine the flow model you should use. Look at parameters such as Mach number and Reynolds number.

2. The model for structure dynamics will also depend on your particular case. Look at the deformation amplitudes you expect, as well as material properties.

3. You may then go ahead and couple those two models, but you might also be lucky: Depending on your FSI problem (forced response, flutter, flow-induced vibration, etc.), and depending on your particular configuration, you might even get away with separate flow and structural analyses, using an uncoupled approach.

John December 29, 2004 10:55

Re: fluid/structure interactions
 
I don't have a model which I require modelling, Its mainly theory based info I was looking for. I was looking for info regarding descriptions of the fluid mechanics/physics/chemistry which has to be modelled to accurately describe the physical behaviour of a physical system, And a description of the kind of mathematical model which could be used to describe the physical system.

And thanks for the quick responces Peter and Mani, appreciated !

Peter Attar December 29, 2004 12:12

Re: fluid/structure interactions
 
Well as was said by myself and Mani the models which will be relevant depend on the problem you are trying to solve. Of course the most complicated model possible will probably model most every situation accurately but using it might be overkill for 90% of the problems..and for some situations there won't be enough days in your lifetime to get the problem solved on the computer. For example for the low Mach number,High Reynolds number flows I could have used a DNS calculation of the Navier-Stokes equations coupled to a nonlinear 3-d structural model modeled using 3D,20 noded tetrahedral elements..however at the end of the day the answer I received using this model would have more than likely not been much different than the one I received modeling the fluid using potential flow and the structure with shell elements.

If you want to get a handle on the possibilities study each component of the coupled problem individually..ie study fluid mechanics,structural mechanics and chemistry.

The combining of the physics into a coupled problem will not change when and if the various models studied in the abovementioned disciplines are relevant.


All times are GMT -4. The time now is 00:59.