scholarly journals Conceptual Modeling of Contaminated Solute Transport Based on Stream Tube Model

2012 ◽  
Vol 02 (04) ◽  
pp. 481-489 ◽  
Author(s):  
Seung-Gun Chung ◽  
Soon-Jae Lee ◽  
Dong-Ju Kim ◽  
Sang-Hyup Lee ◽  
Jae-Woo Choi
Keyword(s):  
Solute Transport ◽  
Conceptual Modeling ◽  
Tube Model ◽  
Stream Tube

A stream tube model for miscible flow

1995 ◽  
Vol 18 (3) ◽  
pp. 263-282 ◽  
Author(s):  
Roland Lenormand ◽  
Biao Wang
Keyword(s):  
Tube Model ◽  
Stream Tube ◽  
Miscible Flow

scholarly journals Comparison of three stream tube models predicting field-scale solute transport

1997 ◽  
Vol 1 (4) ◽  
pp. 873-893 ◽  
Author(s):  
D. Jacques ◽  
J. Vanderborght ◽  
D. Mallants ◽  
D.-J. Kim ◽  
H. Vereecken ◽  
...  
Keyword(s):  
Solute Transport ◽  
Transport Model ◽  
Local Scale ◽  
Transfer Model ◽  
Transport Parameters ◽  
Field Scale ◽  
Stream Tube ◽  
Solute Dispersion ◽  
Measurement Volume ◽  
Piston Flow

Abstract. In this paper the relation between local- and field-scale solute transport parameters in an unsaturated soil profile is investigated. At two experimental sites, local-scale steady-state solute transport was measured in-situ using 120 horizontally installed TDR probes at 5 depths. Local-scale solute transport parameters determined from BTCs were used to predict field-scale solute transport using stochastic stream tube models (STM). Local-scale solute transport was described by two transport models: (1) the convection-dispersion transport model (CDE), and (2) the stochastic convective lognormat transfer model (CLT). The parameters of the CDE-model were found to be lognormally distributed, whereas the parameters of the CLT model were normally distributed. Local-scale solute transport heterogeneity within the measurement volume of a TDR-probe was an important factor causing field-scale solute dispersion. The study of the horizontal scale-dependency revealed that the variability in the solute transport parameters contributes more to the field-scale dispersion at deeper depths than at depths near the surface. Three STMs were used to upscale the local transport parameters: (i) the stochastic piston flow STM-I assuming local piston flow transport, (ii) the convective-dispersive STM-II assuming local CDE transport, and (iii) the stochastic convective lognormal STM-III assuming local CLT. The STM-I considerably underpredicted the field-scale solute dispersion indicating that local-scale dispersion processes, which are captured within the measurement volume of the TDR-probe, are important to predict field-scale solute transport. STM-II and STM-III both described the field-scale breakthrough curves (BTC) accurately if depth dependent parameters were used. In addition, a reasonable description of the horizontal variance of the local BTCs was found. STM-III was (more) superior to STM-II if only one set of parameters from one depth is used to predict the field-scale solute BTCs at several depths. This indicates that the local-scale solute transport process, as measured with TDR in this study, is in agreement with the CLT-hypothesis.

scholarly journals Dynamics of a Cavitating Propeller in a Water Tunnel

2003 ◽  
Vol 125 (2) ◽  
pp. 283-292 ◽  
Author(s):  
Satoshi Watanabe ◽  
Christopher E. Brennen
Keyword(s):  
Present Model ◽  
Gain Factor ◽  
Operating Conditions ◽  
Water Tunnel ◽  
Tube Model ◽  
Cavity Model ◽  
Flow Tube ◽  
Stream Tube ◽  
Thrust Coefficient ◽  
One Dimensional

This study investigates the unsteady dynamics and inherent instabilities of a cavitating propeller operating in a water tunnel. First, the steady characteristics of the cavitating propeller such as the thrust coefficient are obtained by applying continuity and momentum equations to a simple one-dimensional flow tube model. The effects of the tunnel walls as well as those of the propeller operating conditions (advance ratio and cavitation number) are explored. Then the transfer matrix of the cavitating propeller (considered to be the most appropriate way to describe the dynamics of propeller) is obtained by combining the simple stream tube model with the conventional cavity model using the quasi-static cavitation compliance and mass flow gain factor representation. Finally, the surge instability of a cavitating propeller observed by Duttweiler and Brennen (2001) is examined by coupling the present model of the cavitation with a dynamic model for the water tunnel. This analysis shows that the effect of tunnel walls is to promote the surge instability.

A stream tube model for miscible flow

1995 ◽  
Vol 18 (3) ◽  
pp. 245-261 ◽  
Author(s):  
Roland Lenormand
Keyword(s):  
Tube Model ◽  
Stream Tube ◽  
Miscible Flow

Effect of blade pitching on power coefficient of small-scale vertical axis wind turbine at different tip speed ratios

2019 ◽  
Vol 44 (3) ◽  
pp. 313-324 ◽  
Author(s):  
Ramesh K Kavade ◽  
Pravin M Ghanegaonkar
Keyword(s):  
Wind Turbine ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Small Scale ◽  
Tube Model ◽  
Vertical Axis Wind Turbine ◽  
Stream Tube

This article analyses the effect of best blade pitching positions on the power coefficient of vertical axis wind turbine at different tip speed ratios. Analysis of the power coefficient of the vertical axis wind turbine is carried out for optimized six blade pitching curves. The first three pitching curves are designed for the tip speed ratios below 1.5 (0 <  λ < 1.5) and other three are for the tip speed ratios in the range of 0 <  λ < 3. The double multiple stream tube model is used for the present analysis. The results are compared between the optimized and sinusoidal pitching curves. It is concluded that the best optimized pitch position blade method improves the power coefficient than the typical sinusoidal blade pitching in the range of tip speed ratios 0 <  λ < 3.

Sign in / Sign up

Export Citation Format

Share Document