An Overview of the Common Fluid Models Used in Fluid-Structure Interactions

1991 ◽  
Author(s):  
Luther D. Flippen ◽  
Jr
Keyword(s):  
Fluid Models ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
The Common

Transient Pressure Loss in Compressor Station Piping Systems

2010 ◽  
Author(s):  
Klaus Brun ◽  
Marybeth Nored ◽  
Dennis Tweten ◽  
Rainer Kurz
Keyword(s):  
Pressure Loss ◽  
Dynamic Pressure ◽  
Piping System ◽  
Flow Profile ◽  
Fluid Models ◽  
Reciprocating Compressor ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Pressure Losses ◽  
Piping Systems

“Dynamic pressure loss” is often used to describe the added loss associated with the time varying components of an unsteady flow through a piping system in centrifugal and reciprocating compressor stations. Conventionally, dynamic pressure losses are determined by assuming a periodically pulsating 1-D flow profile and calculating the transient pipe friction losses by multiplying a friction factor by the average flow dynamic pressure component. In reality, the dynamic pressure loss is more complex and is not a single component but consists of several different physical effects, which are affected by the piping arrangement, structural supports, piping diameter, and the level of unsteadiness in the flow stream. The pressure losses due to fluid-structure interactions represent one of these physical loss mechanisms and are presently the most misrepresented loss term. The dynamic pressure losses, dominated at times by the fluid-structure interactions, have not been previously quantified for transient flows in compressor piping systems. A number of experiments were performed by SwRI utilizing an instrumented piping system in a compressor closed loop facility to determine this loss component. Steady and dynamic pressure transducers and on-pipe accelerometers were utilized to study the dynamic pressure loss. This paper describes findings from reciprocating compressor experiments and the various fluid modeling studies undertaken for the same piping system. The objective of the research was to quantitatively assess the individual pressure loss components which contribute to dynamic pressure (non-steady) loss based on their physical basis as described by the momentum equation. Results from these experiments were compared to steady state and dynamic pressure loss predictions from 1-D and 3-D fluid models (utilizing both steady and transient flow conditions to quantify the associated loss terms). Comparisons between the fluid model predictions and experiments revealed that pressure losses associated with the piping fluid-structure interactions can be significant and may be unaccounted for by advanced 3-D fluid models. These fluid-to-structure losses should not be ignored when predicting dynamic pressure loss. The results also indicated the ability of an advanced 1-D Navier Stokes solution at predicting inertial momentum losses. Correspondingly, the three-dimensional fluid models were able to capture boundary layer losses affected by 3-D geometries.

Transient Pressure Loss in Compressor Station Piping Systems

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Klaus Brun ◽  
Marybeth Nored ◽  
Dennis Tweten ◽  
Rainer Kurz
Keyword(s):  
Pressure Loss ◽  
Dynamic Pressure ◽  
Piping System ◽  
Flow Profile ◽  
Fluid Models ◽  
Reciprocating Compressor ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Pressure Losses ◽  
Piping Systems

“Dynamic pressure loss” is often used to describe the added loss associated with the time varying components of an unsteady flow through a piping system in centrifugal and reciprocating compressor stations. Conventionally, dynamic pressure losses are determined by assuming a periodically pulsating 1D flow profile and calculating the transient pipe friction losses by multiplying a friction factor by the average flow dynamic pressure component. In reality, the dynamic pressure loss is more complex and is not a single component but consists of several different physical effects, which are affected by the piping arrangement, structural supports, piping diameter, and the level of unsteadiness in the flow stream. The pressure losses due to fluid-structure interactions represent one of these physical loss mechanisms and are presently the most misrepresented loss term. The dynamic pressure losses, dominated at times by the fluid-structure interactions, have not been previously quantified for transient flows in compressor piping systems. A number of experiments were performed by Southwest Research Institute (SwRI) utilizing an instrumented piping system in a compressor closed-loop facility to determine this loss component. Steady and dynamic pressure transducers and on-pipe accelerometers were utilized to study the dynamic pressure loss. This paper describes the findings from reciprocating compressor experiments and the various fluid modeling studies undertaken for the same piping system. The objective of the research was to quantitatively assess the individual pressure loss components, which contribute to dynamic pressure (nonsteady) loss based on their physical basis as described by the momentum equation. Results from these experiments were compared with steady-state and dynamic pressure loss predictions from 1D and 3D fluid models (utilizing both steady and transient flow conditions to quantify the associated loss terms). Comparisons between the fluid model predictions and experiments revealed that pressure losses associated with the piping fluid-structure interactions can be significant and may be unaccounted for by advanced 3D fluid models. These fluid-to-structure losses should not be ignored when predicting dynamic pressure loss. The results also indicated the ability of an advanced 1D Navier–Stokes solution at predicting inertial momentum losses. Correspondingly, the three-dimensional fluid models were able to capture boundary layer losses affected by 3D geometries.

Fluid-Structure Interactions

2009 ◽  
Author(s):  
Michael Paidoussis ◽  
Stuart Price ◽  
Emmanuel de Langre
Keyword(s):  
Fluid Structure Interactions ◽  
Fluid Structure

FLUID-STRUCTURE INTERACTIONS SIMULATION AND VISUALIZATION USING ISPH APPROACH

2019 ◽  
Vol 26 (3) ◽  
pp. 223-238 ◽  
Author(s):  
A. Abdelnaim ◽  
M. Hassaballah ◽  
Abdelraheem M. Aly
Keyword(s):  
Fluid Structure Interactions ◽  
Fluid Structure

Experimental Mixing Parameterization Due to Multiphase Fluid � Structure Interactions

2010 ◽  
Vol 5 (2) ◽  
pp. 1-8
Author(s):  
Ranis N. Ibragimov ◽  
◽  
Akshin S. Bakhtiyarov ◽  
Margaret Snell ◽  
◽  
...  
Keyword(s):  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Multiphase Fluid

scholarly journals Cross-Flow Tidal Turbines with Highly Flexible Blades—Experimental Flow Field Investigations at Strong Fluid–Structure Interactions

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 797
Author(s):  
Stefan Hoerner ◽  
Iring Kösters ◽  
Laure Vignal ◽  
Olivier Cleynen ◽  
Shokoofeh Abbaszadeh ◽  
...  
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Cross Flow ◽  
Speed Ratio ◽  
Fluid Structure Interactions ◽  
Dimensional Parameter ◽  
Fluid Structure ◽  
Passive Flow Control ◽  
Tidal Turbines ◽  
Tidal Turbine

Oscillating hydrofoils were installed in a water tunnel as a surrogate model for a hydrokinetic cross-flow tidal turbine, enabling the study of the effect of flexible blades on the performance of those devices with high ecological potential. The study focuses on a single tip-speed ratio (equal to 2), the key non-dimensional parameter describing the operating point, and solidity (equal to 1.5), quantifying the robustness of the turbine shape. Both parameters are standard values for cross-flow tidal turbines. Those lead to highly dynamic characteristics in the flow field dominated by dynamic stall. The flow field is investigated at the blade level using high-speed particle image velocimetry measurements. Strong fluid–structure interactions lead to significant structural deformations and highly modified flow fields. The flexibility of the blades is shown to significantly reduce the duration of the periodic stall regime; this observation is achieved through systematic comparison of the flow field, with a quantitative evaluation of the degree of chaotic changes in the wake. In this manner, the study provides insights into the mechanisms of the passive flow control achieved through blade flexibility in cross-flow turbines.

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