scholarly journals Hydrodynamics Modeling of Khung Krabaen Lagoon, Chanthaburi Province, Thailand

2018 ◽  
Vol 147 ◽  
pp. 05009
Author(s):  
Pokavanich Tanuspong ◽  
Buranapratheprat Anukul ◽  
Aryuthaka Chittima

Khung Krabaen Lagoon (KKBL) is a small low-inflow water body. There are vast areas of tidal flat occupied nearly 60% of the lagoon that host some of the most productive seagrass habitats in the region. The lagoon is surrounded by mangrove forest and intensive shrimp farms behind it. The KKBL was used as an intake and recipient water for the farms. However due some shrimp disease epidemics and possibly deteriorated water quality, the farms are now taking the intake water from the outer sea through very expensive (to construct and to maintain) irrigation system. Objective of this study is to investigate the KKBL’s hydrodynamics using a numerical simulation model validated with measured data. The simulation model was setup two-dimensionally based on the Delft3D model. Results suggested that water currents inside, at the mouth and at the outer sea of the lagoon are mainly governed by tide and wind. Offshore of the lagoon, there are strong tidal currents flowing along northwest and southeast direction. The tidal currents flow into the lagoon through its mouth before dispersion rapidly inside the lagoon. Mean circulation largely varied seasonally and had direct correlations outer sea seasonal mean currents and the monsoons.

2013 ◽  
Vol 448-453 ◽  
pp. 2545-2550
Author(s):  
Gang Mu ◽  
Ming Li ◽  
Jun An ◽  
Xing Wei Xu ◽  
Shuai Shao

Although numerical simulation is an important method of researching dynamic frequency process, obvious deviations have been found between numerical simulation and the measured trajectory in many accidents. And the existing simulation model and parameters cannot describe the actual dynamic process of frequency accurately. Research was carried out on the influence of four parameters to the dynamic frequency process, which based on the WSCC system. The four parameters include the inertia constant of generator, generator frequency coefficient, dead band and turbine intermediate superheating coefficient. Northeast China power grid and measured data are used to verify the above research conclusion. Checking the dynamic frequency process simulation model and parameters can improve the accuracy of dynamic frequency process simulation on the base of the measured trajectory and the physical characteristics of the parameters. It can also give efficient foundation for the setting work of UFLS, overcoming the previous conservative operation mode and so on.


2005 ◽  
Vol 22 (6) ◽  
pp. 721-734 ◽  
Author(s):  
S. Y. Erofeeva ◽  
Laurie Padman ◽  
Gary Egbert

Abstract The application of a generalized inverse approach for assimilating vessel-mounted acoustic Doppler current profiler (VM-ADCP) data into numerical solutions of barotropic tides is described. The derived estimates of tidal currents can be used to detide the VM-ADCP data and expose underlying mean circulation. The methodology is illustrated with data assimilation models of tidal currents in the Ross Sea. The prior solution, obtained by solving the nonlinear shallow-water equations by time stepping with a linear bottom friction parameterization and elevation of open boundary conditions obtained from a circum-Antarctic tide model, provides reasonably good fit to most available moored current meter data. Two inverse solutions were obtained: one assimilating moored current meter records and the other assimilating three cruises of VM-ADCP data. Fitting either the mooring time series or the VM-ADCP records leads to only small changes relative to the prior solution currents, except over the shelf break where short length scale, energetic diurnal topographic vorticity waves are present. It is shown that the dynamics embedded in the representer functions provides reasonable tidal corrections even with no prior information about forcing at open boundaries.


2020 ◽  
Author(s):  
Lanhua Luo ◽  
Fayuan Li

<p>Gully development is an important topic in the evolution of modern geomorphology. The study of the development process of gullies is key to explain the genesis, mechanism and spatial differentiation of loess geomorphology. Geographic cellular automata (Geo-CA) can simulate complex geographical phenomena by expanding and elements of Cellular automata (CA). This study explores the mechanism of the development process of loess gullies while taking into account the dynamic factors of head-cut erosion. Based on geographic cellular automata (Geo-CA), the transition rules for gully evolution are designed, including the rules of gully head region, the rules of water infiltration, flow direction rule, flow rules, and sediment transport rules. Based on the small simulated Loess watershed under artificial rainfall, the simulation model of loess gully evolution is constructed and implemented. In order to evaluate the accuracy of the simulation results, the negative terrain, Hypsometric Integral (HI) and a gully head confusion matrix of the simulated results and the measured data are compared. The evaluation produces encouraging results in terms of numeric accuracy and spatial distribution, in agreement with the evolution of the loess gully. In addition, the simulation model of loess gully evolution this study proposed is applied to the evolution of a natural watershed, the Madigou watershed located in Jingbian County, Yulin City, Shaanxi Province. The comparison between the simulated results of the model and the measured data is used to verify the validity of the model. All the results show that the evolution model of loess gully based on Geo-CA is satisfactory in simulating the process of loess gully evolution, which provides a new research method and ideas for in-depth study of the process of gully evolution. </p>


2013 ◽  
Vol 291-294 ◽  
pp. 882-885
Author(s):  
Lei Zhang ◽  
Jun Liu

The charger for the electric vehicle (EV) is a nonlinear device, and will cause harmonic pollution when put into operation. This paper, firstly, analyzes harmonic caused by charger theoretically and defines its equivalent model as a three-phase full-bridge controlled rectifier, getting the characteristics of charger through the Fourier analysis of the switching function. Secondly, this paper builds the simulation model of the charger using Matlab/Simulink and replaces the car battery with a nonlinear resistor with resistance value changing over time. The parameters in the simulation model are the same as the charging stations in use and the results verify the charger’s harmonic characteristics. Finally, compared with the measured data, the results show the simulation model is suitable for engineering calculations.


2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Ziqian Chen ◽  
Janne Dragsted ◽  
Simon Furbo ◽  
Bengt Perers ◽  
Jianhua Fan

A mathematical model simulating the emptying behavior of a pressurized solar collector loop with solar collectors with a good emptying behavior is developed and validated with measured data. The calculated results are in good agreement with the measured results. The developed simulation model is therefore suitable to determine the behavior of a solar collector loop during stagnation. A volume ratio R, which is the ratio of the volume of the vapor in the upper pipes of the solar collector loop during stagnation and the fluid content of solar collectors, is introduced to determine the mass of the collector fluid pushed into the expansion vessel during stagnation, Min. A correlation function for the mass Min and the volume ratio R for solar collector loops is obtained. The function can be used to determine a suitable size of expansion vessels for solar collector loops.


Irriga ◽  
2003 ◽  
Vol 8 (1) ◽  
pp. 51-62
Author(s):  
Carlos Alberto Vieira de Azevedo ◽  
Roberto Vieira Pordeus ◽  
Jonildo Irenildo Silveira ◽  
Vera Lúcia Antunes de Lima ◽  
José Dantas Neto

INFLUÊNCIA DA LÂMINA REQUERIDA NO DESEMPENHO DA IRRIGAÇÃO POR SULCO  Carlos Alberto Vieira de Azevedo Roberto Vieira Pordeus Jonildo Irenildo SilveiraVera Lúcia Antunes de Lima José Dantas NetoDepartamento de Engenharia Agrícola, Universidade Federal de Campina Grande, Campina Grande, PB. CEP 58109-970. E-mail: [email protected]  1 RESUMO  No Brasil, assim como na maioria dos outros países, o sistema de irrigação por sulcos é um dos mais utilizados. Dessa forma, esta pesquisa objetivou avaliar a influência da lâmina requerida no desempenho desse sistema, para diferentes tipos de solo e comprimento de sulco. A análise de sensibilidade do desempenho foi desenvolvida mediante simulações do processo da irrigação por sulco, feitas pelo procedimento matemático hidrodinâmico do modelo SIRMOD (Surface Irrigation Simulation Model). Em todos os estudos de caso adotou-se a estratégia de manejo com vazão constante e a condição de irrigação adequada. As simulações foram realizadas em quatro tipos de solo, seis lâminas d’água e quatro comprimentos de sulco. Para os tipos de solo estudados observa-se que, no comprimento de sulcos de 100m, a eficiência de aplicação decresce à medida que a lâmina requerida aumenta, mas no sulco com comprimento de 250m ela aumenta sempre que a lâmina requerida também aumenta.  UNITERMOS: irrigação por sulcos, desempenho, lâmina requerida  AZEVEDO, C.A.V.; PORDEUS, R.V.; SILVEIRA, J.I.; LIMA, V.L.A. DANTAS NETO, J. INFLUENCE OF THE REQUIRED WATER DEPTH ON THE FURROW IRRIGATION PERFORMANCE  2 ABSTRACT  Considering the great using of the furrow irrigation system in Brazil as well as in most countries of the world, this research had the objective of evaluating the influence of the required water depth on the performance of that system, for different soil types and furrow lengths. The performance sensitivity analysis was developed through simulations of the furrow irrigation process performed by the hydrodynamic mathematical procedure of the SIRMOD model (Surface Irrigation Simulation Model). For all case studies, the continuous flow management strategy and the adequate irrigation condition were adopted. The studies were accomplished in four soil types, six required water depths and four furrow lengths. For the soil types studied, it is observed that in the 100m furrow length, theapplication efficiency decreases as the required water depth increases, but in the 250 m furrow length the application efficiency increases as the required water depth increases.  KEYWORDS: furrow irrigation, performance, required water depth 


2021 ◽  
Author(s):  
Miranda Rashani ◽  
Ardeshir Mahdavi

AbstractThe energy performance of residential buildings depends on a large number of interrelated factors. The present paper outlines an approach to developing a building thermal simulation model through real-time data and sensitivity analyses. To this end, three existing multi-family apartment buildings in Pristina, Kosovo, were selected. Initially, thermal simulation models were created using multiple data sources. Model outputs were further evaluated via comparison with available and measured data. Consequently, the most influential input parameters were identified and adjusted to calibrate the models. The resulting calibrated models can be deployed to investigate the potential of alternative retrofit measures.


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