One-dimensional channel network modelling and simulation of flow conditions during the 2008 ice breakup in the Mackenzie Delta, Canada

Author(s):  
Julia Blackburn ◽  
Yuntong She
1960 ◽  
Vol 64 (598) ◽  
pp. 632-635 ◽  
Author(s):  
R. A. A. Bryant

The concept of small stage efficiency is introduced when studying one-dimensional gas flow in nozzles in order to permit a closer approximation of real flow conditions than is possible from an isentropic analysis. It is more or less conventional to assume the flow conditions are adiabatic whenever the small stage efficiency is used. That is to say, small stage efficiency is generally considered in relation to flows contained within adiabatic boundaries, in which case it becomes a measure of the heat generated by internal frictional effects alone.


2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Subrata K. Ghosh ◽  
R. K. Sahoo ◽  
Sunil K. Sarangi

A study has been conducted to determine the off-design performance of cryogenic turboexpander. A theoretical model to predict the losses in the components of the turboexpander along the fluid flow path has been developed. The model uses a one-dimensional solution of flow conditions through the turbine along the mean streamline. In this analysis, the changes of fluid and flow properties between different components of turboexpander have been considered. Overall, turbine geometry, pressure ratio, and mass flow rate are input information. The output includes performance and velocity diagram parameters for any number of given speeds over a range of turbine pressure ratio. The procedure allows any arbitrary combination of fluid species, inlet conditions, and expansion ratio since the fluid properties are properly taken care of in the relevant equations. The computational process is illustrated with an example.


2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Stephen A. Solovitz ◽  
Larry G. Mastin ◽  
Farhad Saffaraval

Particle image velocimetry (PIV) experiments have been conducted to study the velocity flow fields in the developing flow region of high-speed jets. These velocity distributions were examined to determine the entrained mass flow over a range of geometric and flow conditions, including overpressured cases up to an overpressure ratio of 2.83. In the region near the jet exit, all measured flows exhibited the same entrainment up until the location of the first shock when overpressured. Beyond this location, the entrainment was reduced with increasing overpressure ratio, falling to approximately 60% of the magnitudes seen when subsonic. Since entrainment ratios based on lower speed, subsonic results are typically used in one-dimensional volcanological models of plume development, the current analytical methods will underestimate the likelihood of column collapse. In addition, the concept of the entrainment ratio normalization is examined in detail, as several key assumptions in this methodology do not apply when overpressured.


2006 ◽  
Vol 50 (12) ◽  
pp. 1885-1886 ◽  
Author(s):  
Jennifer C. Hou ◽  
P.R. Kumar

2019 ◽  
Vol 18 (1) ◽  
pp. 27-37
Author(s):  
Dariusz Gąsiorowski ◽  
◽  
Wojciech Artichowicz ◽  

2018 ◽  
Vol 7 (4.35) ◽  
pp. 880 ◽  
Author(s):  
H. Basri ◽  
L. M. Sidek ◽  
D. S. Shih ◽  
H. C. Lloyd ◽  
W. H. Azad ◽  
...  

Reservoir inflow forecasting assists dam operator in reservoir operation by providing advance information on lake level. This paper discusses on the application of the physical-based numerical model to simulate one-dimensional channel network using WASH123D Model. The model was developed to simulate streamflow at two locations namely Sg Kejar and Sg Tiang, located in the Temengor catchment. The WASH123D model performed channel routing using shallow water equation. The model input data includes rainfall from 5 rainfall stations, river cross sections and simulated runoff data using SCS Method. Due to unavailable observed data, results comparisons were performed using streamflow results obtained using InfoWorks RS Platform. The peak flow from simulation results at Sg Kejar & Sg Tiang Station is 152.6m3/s and 36.6m3/s. The analysis shows good agreement for both simulations with Nash-Sutcliffe Efficiency of 0.68 for Sg Kejar and 0.99 for Sg Tiang. It is suggested that model recalibration shall be made once there is enough water level data to enable more accurate representation of spatial heterogeneity in the catchment processes.   


Author(s):  
Riccardo Baudille ◽  
Gino Bella ◽  
Rossella Rotondi

In multi hole Diesel injectors, cavitation can offer advantages in the development on the fuel spray, because the primary atomization of the liquid fuel jet can be improved due to the enhanced turbulence. Several multi dimensional models of cavitating nozzle flow have been developed in order to provide information about the flow at the exit of a cavitating orifice. In this paper an analytical one-dimensional model, by Sarre et al. [1], to predict the flow conditions at the exit of a cavitating nozzle, is analyzed. The results obtained are compared with the ones obtained using the multi dimensional code Fluent in order to investigate the predictive capability of the one-dimensional code. The model provides initial conditions for multidimensional spray modeling: the effective injection velocity and the initial drop or injected liquid ‘blob’ size. The simulations were performed using an improved version of the KIVA3V code, in which an hybrid break up model, developed by the authors, is used and the results in terms of penetrations and global SMD are compared with the experimental ones. The one dimensional model predicts reasonable discharge coefficient for sharp injector geometry. Where the r/d ratio increases and the cavitation effects appear not clearly marked there are same discrepancies between the one dimensional and the multidimensional approach.


Sign in / Sign up

Export Citation Format

Share Document