Application of Bond Graphs to Thermofluid Processes and Systems

1985 ◽  
Vol 107 (4) ◽  
pp. 241-245 ◽  
Author(s):  
R. Shoureshi ◽  
K. McLaughlin
Keyword(s):  
Single Phase ◽  
Momentum Equation ◽  
Variable Density ◽  
Rate Of Change ◽  
Bond Graphs ◽  
State Variable ◽  
The Past ◽  
Variable Density Flow ◽  
Density Flow ◽  
Gibb's Equation

Over the past few years a study was focused on the development of bond graphs for thermofluid processes and systems using the true power variables of temperature and time rate of change of entropy. This paper summarizes results of the study. Discussion begins with the study of a simple case of single phase incompressible fluid flow and ends with a completely general case of multiphase, variable density flow. Variations in density require introduction of the momentum equation to the bond graph. Inclusion of entropy as a state variable necessitates the use of Gibb’s equation and its representation by means of bond graphs. This paper presents these formulations and representations, and compares dynamic results predicted by bond graphs with those of classical approaches.

Numerical Verification of the Solutions for Groundwater Flow in a Coastal Extensive Land Mass

2013 ◽  
Vol 864-867 ◽  
pp. 2292-2297
Author(s):  
Hai Peng Guo
Keyword(s):  
Analytical Solutions ◽  
Land Reclamation ◽  
Variable Density ◽  
Numerical Code ◽  
Numerical Verification ◽  
Variable Density Flow ◽  
Density Flow ◽  
Type Flow ◽  
Land Mass ◽  
The Impact

This paper reviews the analytical solutions for the impact of land reclamation on the ground water level and the saltwater interface with unconfined groundwater conditions in coastal aquifers. The applicability of the analytical solutions is somewhat limited by assumptions such as Dupuit-type flow and the Ghyben-Herzberg relation. Variable-density flow and solute transport simulations conducted by the numerical code FEFLOW were used to evaluate the accuracy of these analytical solutions. Three field-scale hypothetical cases were simulated for the numerical verification. The results show that a seepage face occurs in the numerical results rather than in the analytical solutions, but only minor difference occurs between the numerical and analytical solutions. This implies that the analytical solutions are reasonable despite the used assumptions.

On the generation of instabilities in variable density flow

1994 ◽  
Vol 30 (4) ◽  
pp. 913-927 ◽  
Author(s):  
Robert A. Schincariol ◽  
Franklin W. Schwartz ◽  
Carl A. Mendoza
Keyword(s):  
Variable Density ◽  
Variable Density Flow ◽  
Density Flow

scholarly journals Experimental and Numerical Studies on the Vertical Flow of Variable Density Fluid in Different Directions

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Zhifang Zhou ◽  
Boran Zhang ◽  
Qiaona Guo ◽  
Shumei Zhu
Keyword(s):  
Salt Water ◽  
Water Injection ◽  
Experimental Studies ◽  
Engineering Application ◽  
Variable Density ◽  
Vertical Flow ◽  
Construction Time ◽  
One Dimensional ◽  
Variable Density Flow ◽  
Density Flow

Injecting freshwater and pumping salt water are effective methods to restore the salt water in a coastal area. Based on a one-dimensional vertical experiment, the variable density flow is simulated under the condition of different injection directions and injection rates of fresh water. A one-dimensional mathematical model of variable density flow and solute transport is established. The mathematical models are solved using the implicit difference method. Fortran code is developed to simulate and verify the vertical flow of variable density flow in different directions. Through both numerical simulation and experimental studies, it is found that the variable density fluid in the direction of reverse gravity is different from that in the direction of gravity. On this basis, the most effective desalination model of salt water is further discussed. It provides a theoretical and technical method for the restoration of salt water in the vertical injection of freshwater. In order to improve the remediation efficiency and reduce the cost in the engineering application, the suitable water injection rate should be ensured, considering the suitable construction time and zone of a study area.

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