scholarly journals Blending Time and Velocity Variations During Blending in a Tank Using Dual Opposing Jets

2011 ◽  
Author(s):  
Robert A. Leishear ◽  
Mark D. Fowley ◽  
Michael R. Poirier ◽  
Si Y. Lee ◽  
Timothy J. Steeper
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Statistical Analysis ◽  
Confidence Level ◽  
Experimental Error ◽  
Total Change ◽  
Process Industries ◽  
Actual Variation ◽  
Acid And Base ◽  
Ph Probes

Blending times are required for many process industries, and statistical analysis of the measured blending times was used to determine a relationship between CFD (computational fluid dynamics) predictions and experiments. A 95% blending time occurs when tank contents are sufficiently blended to ensure that concentration throughout the tank is within ±5% of the total change in concentration. To determine 95% blending times, acid and base tracers were added to an eight foot diameter tank, and the pH data were recorded to monitor blending. The data for six pH probes located throughout the tank were normalized to a range of 0 to 1. Then the blending time was established when the pH converged between 0.95 and 1.05 on the normalized graphs. Evaluation of results from 79 different tests concluded that the maximum blending time occurred randomly at any one of the six pH probes. The research then considered the calculated 95% blending times, which had uncertainties up to more than 100% at a 95% confidence level. However, this uncertainty is considered to be an actual variation in blending time, rather than an experimental error. Not only were there significant variations in the blending times, but there were significant variations in the velocities measured at different points in the blending tank.

Influence Mechanisms of Manufacture Variations on Supersonic/Transonic Blade Aerodynamic Performances

2020 ◽  
Author(s):  
Baojie Liu ◽  
Jiaxin Liu ◽  
Xianjun Yu ◽  
Dejun Meng ◽  
Wenbin Shi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Pressure ◽  
Statistical Analysis ◽  
Mach Number ◽  
Systematic Errors ◽  
Aerodynamic Performance ◽  
Aerodynamic Performances ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

Abstract The results of previous studies have proved that manufacture variations can cause a noticeable influence on compressor aerodynamic performance. The main objective of this paper is to investigate the influence rules and mechanisms of manufacture variations on supersonic/transonic blades aerodynamic performance. The variations used in this study were measured from some newly manufactured high-pressure compressors. In the present study, several blade sections with different design Mach number conditions are selected for further statistical analysis of measured deviation data. Therefore, some systematic errors in the deviation data have been revealed. Based on these data, the computational fluid dynamics (CFD) method has been used to obtain the aerodynamic performances of a large number of the measured blade elements. And then, the analysis of the influence rules of manufacture variations on blade aerodynamic performance in different Mach number conditions has been carried out. The present results indicate that the effects of manufacture variations on blade aerodynamic performance in the lower Mach number (0.8) condition are much more significant comparing to that in the higher Mach number (0.9∼1.2) conditions. Based on this, influence mechanisms of manufacture variations on positive incidence range and negative incidence range have been analyzed. The differences of influence mechanisms in different Mach number conditions are the focus of research.

scholarly journals Statistical Study of the Effect of Particle Properties on the Particle Penetration in the Idealized Trachea

2020 ◽  
Vol 11 (10) ◽  
pp. 477-482
Author(s):  
R. Piemjaiswang ◽  
◽  
B. Chalermsinsuwan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Statistical Analysis ◽  
Statistical Study ◽  
Particle Density ◽  
Three Dimensional ◽  
Particle Diameter ◽  
Quadratic Effect ◽  
Particle Properties ◽  
Particle Penetration

The particulate matter (PM) is one of the harmful pollutants that causing an impact on human health. To study the significance of those small particle properties, the research had been conducted using three-dimensional computational fluid dynamics with the Eulerian-Lagrangian approach. The trajectories of the particles were tracked and recorded. The effect of particle diameter, particle density, and particle sphericity on the escaped particle percentage was investigated and characterized using the statistical analysis of variance. The results showed that the particle diameter, particle density, their interaction, and the quadratic effect of the particle diameter played important roles in the penetration of those injected particles.

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