1388
4
2
42
73
0
ارزیابی عملکرد دو الگوریتم کنترل در بهبود فرایند بهره برداری از کانال اصلی غرب شبکه آبیاری دز
Performance Assessment of two Applied Algorithm Controls in the West Main Canal of Dez Irrigation Network
http://jhyd.iha.ir/article_85519.html
10.30482/jhyd.2009.85519
0
1
Automating the irrigation networks is one of the new approaches for making a proper watermanagement decision to improve the efficiency of these systems. In the present study, two robustcontrol systems of the Local Upstream PI Feedback Control with Filters and Centralized DistantDownstream PI Feedback Control with Filters and Decouplers were designed and applied for the westmain canal of Dez irrigation network. The control algorithms programmed in MATLAB m-files andconnected to the SOBEK Canal Flow module through the SOBEK Real Time Control module. Toevaluate the efficiency of the control algorithms, the performance criteria of the Maximum AbsoluteError, Integral Absolute Error and Steady State Error were considered during the simulations of onemonth with regard to the real off takes schedule with the highest variations within the cropping season.The results indicated that the applied control algorithms have considerable potential to closely matchthe discharge at the downstream check structures with those ordered by water users while maintainingthe water level throughout the length of the canal. It was also concluded that the centralized controlsystem has more efficiency compared to local control system which provides flexible, demandoriented and accurate operation procedure. Considering that local upstream controller may beconsidered as an option, either as the main control system or as the backup system for the canal systemautomation.
1
18
سعید
عیسی پور
S.
Isapoor
ایران
علی اصغر
منتظر
A.
Montazar
ایران
almontaz@ut.ac.ir
0
بررسی هیدرولیکی جریان آب و هوا در مدل آزمایشگاهی مجرای تحت فشار به روش پردازش تصاویر
Hydraulics of Air-Water Flow in a Pressurized Pipeline Model Using Image Processing
http://jhyd.iha.ir/article_85520.html
10.30482/jhyd.2009.85520
0
1
The study of two-phase fluid flow is of great importance in tunnels and pressurized pipelines, due tothe disturbances caused by pressure fluctuation, bubble bursting, energy release and erosion. The gasreleases from the water as the pressure reduces, and, hence, trapped in water pipelines. This effect hasbeen observed and found to be detrimental.The image processing technique is applied for estimating different parameters such as; void fractionand length, period and celerity of unstable two-phase slug flow, using Photoshop and Matlab software,based on experimental model. Necessary images were collected using two digital cameras. It is shownthat, the image processing technique can be used as a good tool for determination of two-phase flowcharacteristics. Results show that the slug flow characteristics including length, frequency and celerityhave significant effects on void fraction. By increasing the air/water discharge ratio the void fractionincreases and by in creasing the slug frequency the void fraction decreases.
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34
عبدالرضا
کبیری سامانی
Abdorreza
Kabiri-Samani
دانشیار، دانشکده مهندسی عمران، دانشگاه صنعتی اصفهان
ایران
akabiri@cc.iut.ac.ir
سیدمحمود
برقعی
S.M.
Borghei
ایران
امیرحسین
پیرقطاری
A.H.
Pirghatari
ایران
0
شبیه سازی عددی تغییرات بستر کانال های آبرفتی در قوس 180 درجه
Numerical Simulation of Bed Evolution in 180 Degree Alluvial Channel Bend
http://jhyd.iha.ir/article_85521.html
10.30482/jhyd.2009.85521
0
1
The river bed evolution in 180 degree alluvial channel bend is numerically simulated using FLUENTbased on Eulerian two-phase model that implements Euler–Euler coupled governing equations forfluid and solid phases and a modified k–; turbulence closure for the fluid phase. This two-phase modelpredicts sediment transport from more fundamental dynamical equations, thereby avoiding the use ofpurely empirical sediment transport formula. Such formulas have been found to be case-dependent,thus limiting their general use to cover a broad range of flow configurations. Both flow–particle andparticle–particle interactions are considered in the model. During the simulations, the interfacebetween sand and water is specified using a threshold volume fraction of sand, and the evolution of thebed form is studied in detail. The predictions of bed form evolution are in good agreement withprevious laboratory measurements. In addition, the computational results indicate the presence of anew mechanism in sediment transport that can be called 'Laminated Load' hereafter.
35
43
علی
سواریان
A.
Savarian
ایران
امیر حسین
نیک سرشت
A.H.
Nikseresht
دانشگاه صنعتی شیراز
ایران
nikser@sutech.ac.ir
ناصر
طالب بیدختی
N.
Talebbeydokhti
ایران
nassertaleb@gmail.com
0
مقایسه معیارهای قطعی و غیرقطعی آغاز حرکت ذرات رسوب دانه ای در حوضچه های جزر و مدی
Comparison of Deterministic and Stochastic Criteria for the Initiation of Sediment Motion in Tidal Basins
http://jhyd.iha.ir/article_85522.html
10.30482/jhyd.2009.85522
0
1
Current study is refinement and application of a two-dimensional horizontal numerical model topredict geo-morphological changes in tidal basins. An ADI finite difference algorithm has been usedfor solving the governing equations, which consist of the conservation of mass and momentum for thehydrodynamics, the transport equation for suspended sediment fluxes and the sediment massconservation equation for bed level changes. The model includes three criteria for the initiation ofmotion (i.e. Shields (1936), Kolahdoozan (1999) and Zanke (2003)). Since the flow is turbulent, itscomponents have a random nature and sediment transport processes can be expressed by stochasticapproaches. In this study both deterministic and stochastic methods were included in bed loadcomputations. Verification of model results have been carried out by an experimental study cited inthe literature. Comparisons of results for different criteria for the initiation of motion shows that theunsteadiness parameters of current have a major effect on the bed level changes in comparison withturbulence structure of the flow.
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57
حنیفه
ایمانیان
H.
Imanian
ایران
h.imanian@alzahra.ac.ir
مرتضی
کلاهدوزان
Morteza
Kolahdoozan
دانشگاه امیرکبیر-دانشکده عمران و محیط زیست
ایران
mklhdzan@aut.ac.ir
0
بررسی پروفیل سطح آزاد جریان پایدار در اطراف پایه های استوانه ای با مدل سازی عددی
Investigation of the Free Surface Profile of a Steady Flow around a Cylindrical Pier Using Numerical Model
http://jhyd.iha.ir/article_85523.html
10.30482/jhyd.2009.85523
0
1
A numerical model has been developed to evaluate the profile of free surface flow around a cylindricalbridge pier. The Reynolds equations of the shallow waters have been discredited using the finitedifference method. The resulting equations were then solved using the explicit MacCormack'stechnique. For the closed boundary conditions, the free-mirror condition has been imposed with nonuniformgrids. The numerical model results were then verified against experimental data and theagreement between them was fairly good.It was also found that for the small values of the Froude number, the model could predict theexperimental data reasonably well, whereas for the large values of this number, there were somediscrepancies between model results and measured data.
59
65
یوسف
حسن زاده
Y.
Hassanzadeh
هیات علمی
ایران
حبیب
حکیم زاده
H.
Hakimzadeh
ایران
hakimzadeh@sut.ac.ir
حامد
سرورام
H.
Sarvram
ایران
hamed.sarveram@gmail.com
هادی
دل افروز
H.
Delafrooz
ایران