Predicting Wall Pressure Fluctuation over a Backward-Facing Step Using Detached Eddy Simulation

2009 ◽  
Vol 46 (6) ◽  
pp. 2115-2120 ◽  
Author(s):  
Jean-François Dietiker ◽  
Klaus A. Hoffmann
Keyword(s):  
Pressure Fluctuation ◽  
Wall Pressure ◽  
Detached Eddy Simulation ◽  
Backward Facing Step ◽  
Eddy Simulation ◽  
Wall Pressure Fluctuation

Wall pressure-fluctuation spectra at small backward-facing steps

2000 ◽  
Author(s):  
B. Efimtsov ◽  
N. Kozlov ◽  
S. Kravchenko ◽  
A. Andersson
Keyword(s):  
Pressure Fluctuation ◽  
Wall Pressure ◽  
Wall Pressure Fluctuation

Investigation of Aerator Flow Pressure Fluctuation Using Detached Eddy Simulation with VOF Method

2022 ◽  
Vol 148 (1) ◽  
Author(s):  
Zhengwen Li ◽  
Zhaowei Liu ◽  
Haoran Wang ◽  
Yongcan Chen ◽  
Ling Li ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Vof Method ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Flow Pressure

Intrinsic Mode Entropy Analysis of Tube-Wall Pressure Fluctuation Signals in the Kenics Static Mixer

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Hui-Bo Meng ◽  
Zhi-Qiang Liu ◽  
Yan-Fang Yu ◽  
Qiang Xiong ◽  
Jian-Hua Wu
Keyword(s):  
Pressure Fluctuation ◽  
Tube Wall ◽  
Sample Entropy ◽  
Wall Pressure ◽  
High Frequency Component ◽  
Static Mixer ◽  
Flow Rates ◽  
Multi Scale ◽  
Wall Pressure Fluctuation ◽  
Macro Scale

The multi-scale nonlinear hydrodynamics in Kenics Static Mixer (KSM) with 100 mm in diameter and 2 in aspect ratio was investigated in this work. The time series of tube-wall pressure fluctuation signals were measured at different flow rates ranged of 100~600 L•h-1 and at different axial positions in the range of 420~580 mm away from the cross-section of mixer inlet. It is difficult for composite signals to make an effective analysis by Sample Entropy (SampEn) based on a single scale. The complexity of tube-wall pressure fluctuation signals in a Kenics static mixer was investigated using Intrinsic Mode Entropy (IMEn) based on Sample Entropy algorithm and Empirical Mode Decomposition (EMD) method. Data sampling length and tolerance are optimized based on intrinsic mode entropy. Results of multi-scale analysis of pressure fluctuations indicated that the Sample entropy reaches maximum in the first scale and progressively decreases according to increase of the decomposed order. It is clear that the movement of high frequency component of the pressure signal is the most complicated and is rich in randomness. With the decomposition scales increasing, the complexity of signal decreases and approaches periodic motion eventually. The intrinsic mode entropy of the tube wall pressure signals in KSM has similar development tendencies in different flow rates. Besides, as the flow rates increased, the macro-scale vortexes play a more and more important role and guide the system to develop toward the stable state.

Influence of wall roughness on the static performance and pressure fluctuation characteristics of a double-suction centrifugal pump

2018 ◽  
Vol 232 (7) ◽  
pp. 826-840 ◽  
Author(s):  
Zhifeng Yao ◽  
Min Yang ◽  
Ruofu Xiao ◽  
Fujun Wang
Keyword(s):  
Centrifugal Pump ◽  
Pressure Fluctuation ◽  
Pressure Fluctuations ◽  
Design Flow ◽  
Experimental Investigations ◽  
Wall Roughness ◽  
Detached Eddy Simulation ◽  
Centrifugal Pumps ◽  
Eddy Simulation ◽  
Static Performance

The unsteady flow field and pressure fluctuations in double-suction centrifugal pumps are greatly affected by the wall roughness of internal surfaces. To determine the wall roughness effect, numerical and experimental investigations were carried out. Three impeller schemes for different wall roughness were solved using detached eddy simulation, and the performance and pressure fluctuations resolved by detached eddy simulation were compared with the experimental data. The results show that the effects of wall roughness on the static performance of a pump are remarkable. The head and efficiency of the tested double-suction centrifugal pump are raised by 2.53% and 6.60% respectively as the wall roughness is reduced by means of sand blasting and coating treatments. The detached eddy simulation method has been proven to be accurate for the prediction of the head and efficiency of the double-suction centrifugal pump with roughness effects. The influence of the roughness on pressure fluctuation is greatly dependent on the location relative to the volute tongue region. For locations close to the volute tongue, the peak-to-peak value of the pressure fluctuations of a wall roughness of Ra = 0.10 mm may be 23.27% larger than the case where Ra = 0.02 mm at design flow rate.

Hydrodynamic and Hydroacoustic Phenomena in the Propeller Wake-Rudder Interaction

2014 ◽  
Author(s):  
Mario Felli ◽  
Silvano Grizzi ◽  
Massimo Falchi
Keyword(s):  
Pressure Fluctuation ◽  
Holistic Approach ◽  
Wall Pressure ◽  
Marine Propeller ◽  
Flow Measurements ◽  
Time Resolved ◽  
Propeller Wake ◽  
Wall Pressure Fluctuation ◽  
Free Running

The present paper describes the major mechanisms underlying the hydroacoustic and hydrodynamic perturbations in a rudder operating in the wake of a free running marine propeller. The study was based on a holistic approach which concerned time resolved visualizations and detailed flow measurements around the rudder as well as wall-pressure fluctuation measurements over the rudder surface, at different deflection angles.

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