Experimental and numerical investigation of pressure drop coefficient and static pressure difference in a tangential inlet cyclone separator

2012 ◽  
Vol 66 (11) ◽  
Author(s):  
Fuat Kaya ◽  
Irfan Karagoz
Keyword(s):  
Pressure Drop ◽  
Pressure Difference ◽  
Static Pressure ◽  
Numerical Technique ◽  
Pipe Length ◽  
Inlet Velocity ◽  
Viscous Forces ◽  
Static Pressure Difference ◽  
High Reynolds ◽  
Experimental Data Analysis

AbstractThe aim of this study was to investigate the pressure drop coefficient and the static pressure difference related to the natural vortex length and to evaluate the results for gas-particle applications. CFD simulations were carried out using a numerical technique which had been verified previously. Results obtained from the numerical simulations were compared with the experimental data. Analysis of the results showed that the pressure drop coefficient decreases with the increasing inlet velocity, becoming almost constant above a certain value of the inlet velocity. The reason is that the effect of viscous forces decreases at high Reynolds numbers. The pressure drop coefficient also decreases with the increasing exit pipe diameter and decreasing exit pipe length.

Phenomenon of labyrinth seal with low static pressure difference and large clearance

2004 ◽  
Vol 7 (1) ◽  
pp. 63-75 ◽  
Author(s):  
K. Shimada ◽  
K. Kimura ◽  
S. Ichikawa ◽  
H. Ohta ◽  
K. Aoki
Keyword(s):  
Pressure Difference ◽  
Static Pressure ◽  
Labyrinth Seal ◽  
Static Pressure Difference

Flow Distribution and Pressure Drop in Steady Airflow Through a Selective Laser Sintered Human Tracheobronchial Airway Model

2003 ◽  
Author(s):  
Kah-Hoe Tan ◽  
Ramkumar N. Parthasarathy ◽  
M. Cengiz Altan ◽  
David L. Johnson ◽  
R. E. Clinkenbeard
Keyword(s):  
Pressure Drop ◽  
Static Pressure ◽  
Flow Distribution ◽  
Reynolds Numbers ◽  
Flow Rates ◽  
Physiological Flow ◽  
Static Pressure Difference ◽  
The Mean ◽  
The Relationship ◽  
Airway Model

The flow distribution and pressure drop of steady airflow in the human central airways were studied experimentally using an anatomically correct, selective laser sintered (SLS) human tracheobronchial airway model. Measurements were made for tracheal flow rates ranging from 0.1 to 2.67 liters per second, which correspond to normal physiological flow ranges. The mean air velocities at the exit orifices of the airway model were detected by means of a pitot static tube connected to a pressure transducer. The flow rates, the average velocities, and the Reynolds numbers in each branch of the airway model were then computed. In addition, the static pressure difference between the trachea and the airway exits was measured. The experimental measurements were used to determine the relationship between pressure drop and flow rate. The ratio of inlet to total exit area of the model was identified as a significant factor that influenced the pressure drop. The results obtained in the present study will be particularly useful for validating computational studies.

Phenomenon of labyrinth weal with Low static pressure difference and large clearance

2003 ◽  
Vol 6 (4) ◽  
pp. 395-405 ◽  
Author(s):  
K. Shimada ◽  
K. Kimura ◽  
H. Ohta ◽  
K. Aoki
Keyword(s):  
Pressure Difference ◽  
Static Pressure ◽  
Static Pressure Difference

Elementary Mechanics of the Endothelium of Blood Vessels

1993 ◽  
Vol 115 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Y. C. Fung ◽  
S. Q. Liu
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Cell Membrane ◽  
Pressure Difference ◽  
Static Pressure ◽  
Membrane Tension ◽  
Principal Stresses ◽  
Cell Content ◽  
Static Pressure Difference ◽  
Alternative Hypotheses

The endothelium lining human arteries is a continuum of endothelial cells. The flowing blood imposes a shear stress on the endothelium. To compute the internal stress in the endothelium, we use two alternative hypotheses: 1) The cell content is fluid-like so that at steady-state it has no shear stress. 2) The cell content is solid-like. Under hypothesis No. 1, the membrane tension in the upper cell membrane grows in the direction opposite to the blood flow at a rate equal to the blood shear stress. At the junction of two neighboring cells the membrane tension in the downstream cell is transmitted partly to the basal lamina, and partly to the upstream cell. The transmission depends on the osmotic or static pressure difference between the cell and blood. If the static pressure difference is zero, the tension in the upper cell membrane will accumulate upstream. At other values of static pressure, the cell membrane tension may increase, decrease, or fluctuate along the vessel depending on the inclination of the side walls of the cells at the junctions. To determine the sidewall inclinations, we propose to use the complementary energy theorem. Under hypothesis No. 2, the cell content can bear shear, which tends to reduce the cell membrane tension; but the cell membrane tension accumulation phenomenon discussed above remains valid. These results are used to analyze the interaction of the cell membrane and cell nucleus; and the effect of turbulences in the flow on causing large fluctuations in cell membrane tension and vertical oscillations of the nuclei. The implication of tensile stress on the permeability of the cell membrane is discussed. We conclude that for the study of mass transport and stress fibers in the endothelial cells, one should consider the interaction of neighboring endothelial cells as a continuum, and shift attention from the shear stress in the blood to the principal stresses in the cells.

scholarly journals Study on the Leakage and Inter-Stage Pressure Drop Characteristics of Two-Stage Finger Seal

2021 ◽  
Vol 11 (5) ◽  
pp. 2239
Author(s):  
Hailin Zhao ◽  
Hua Su ◽  
Guoding Chen ◽  
Yanchao Zhang
Keyword(s):  
Pressure Drop ◽  
Pressure Difference ◽  
Radial Displacement ◽  
Mean Square ◽  
The Finite Element Method ◽  
Axial Pressure ◽  
Two Stage ◽  
One Stage ◽  
The One ◽  
Lower Contact

To solve the high leakage and high wear problems faced by sealing devices in aeroengines under the condition of high axial pressure difference, the two-stage finger seal is proposed in this paper. The finite element method and computational fluid dynamics (FEM/CFD) coupling iterative algorithm of the two-stage finger seal is developed and validated. Then the performance advantages of two-stage finger seal compared to the one-stage finger seal are studied, as well as the leakage and the inter-stage pressure drop characteristics of two-stage finger seal are investigated. Finally, the measure to improve the inter-stage imbalance of pressure drop of two-stage finger seal is proposed. The results show that the two-stage finger seal has lower leakage and lower contact pressure than the one-stage finger seal at high axial pressure difference, but there exists an inter-stage imbalance of pressure drop. Increasing the axial pressure difference and the root mean square (RMS) roughness of finger element can aggravate the imbalance of pressure drop, while the radial displacement excitation of rotor has little influence on it. The results also indicate that the inter-stage imbalance of pressure drop of the two-stage finger seal can be improved by increasing the number of finger elements of the 1st finger seal and decreasing the number of finger elements of the 2nd finger seal.

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