A stream tube model for miscible flow

1995 ◽  
Vol 18 (3) ◽  
pp. 245-261 ◽  
Author(s):  
Roland Lenormand
Keyword(s):  
1995 ◽  
Vol 18 (3) ◽  
pp. 263-282 ◽  
Author(s):  
Roland Lenormand ◽  
Biao Wang
Keyword(s):  

2003 ◽  
Vol 125 (2) ◽  
pp. 283-292 ◽  
Author(s):  
Satoshi Watanabe ◽  
Christopher E. Brennen

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.


2012 ◽  
Vol 02 (04) ◽  
pp. 481-489 ◽  
Author(s):  
Seung-Gun Chung ◽  
Soon-Jae Lee ◽  
Dong-Ju Kim ◽  
Sang-Hyup Lee ◽  
Jae-Woo Choi

2019 ◽  
Vol 44 (3) ◽  
pp. 313-324 ◽  
Author(s):  
Ramesh K Kavade ◽  
Pravin M Ghanegaonkar

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.


2015 ◽  
Vol 18 (4) ◽  
pp. 153-161 ◽  
Author(s):  
Hieu Thi Hong Le ◽  
Cong Chi Nguyen ◽  
Trong Huu Luong

Horizontal and vertical axis wind turbines (HAWTs and VAWTs) are two main kinds of wind turbines, which are the most popular way to catch energy from the wind. By comparison, VAWTs have some advantages, but they also have the complexity in aerodynamics that needs a deep investigation. A code is developed based on Double multiple stream-tube and corrections of the dynamic stall for Darrieus VAWTs. It is capable of estimating the output power versus different operating conditions defined by the tipspeed- ratio. The code is also validated with experimental data of many SANDIA Darrieus VAWT turbines.


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