Hydraulic Investigation of Triangular Plan Form Vertical Drops

The vertical drop is one of the most widely used hydraulic structures for dissipating the destructive energy of water. The purpose of this research is to investigate the effect of the two difference height, and five vertex angles of a triangular plan form vertical drop on energy dissipation and average velocity using the volume of fluid (VOF) method. The findings revealed that by decreasing vertex angle of the triangular plan form vertical drop, energy dissipation increases. The lowest relative depth of the pool occurs with this drop. In contrast, as the vertex angle of the triangular plan form vertical drop decreases, the average velocity at the foot of the drop increases and the maximum average velocity in the triangular plan form vertical drop with an angle of 60 degrees and a height of 0.2 m is higher than other models. The average downstream velocity also decreases by decreasing the angle  and this decrease is more intense in the center of the channel than on the sides

Three-Dimensional Study of the Effect of Block Roughness Geometry on Inclined Drop

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Solution of the propagation of the waves in open channels by the transfer matrix method

Many problems in mechanics can be solved by the use of the transfer matrix method. The use of this method in hydraulics engineering is not widespread and only limited studies are available. In this study, linearized St. Venant equations were used and the use of transfer matrix in ocean engineering was investigated for long waves in open channels, and numerical application was carried out. The results obtained through the transfer matrix method, which is quite easy to use, program and comprehend, showed similar results obtained from the characteristics method and finite differences method. © 2008 Elsevier Ltd. All rights reserved

Solution of the propagation of the waves in open channels by the transfer matrix method

Many problems in mechanics can be solved by the use of the transfer matrix method. The use of this method in hydraulics engineering is not widespread and only limited studies are available. In this study, linearized St. Venant equations were used and the use of transfer matrix in ocean engineering was investigated for long waves in open channels, and numerical application was carried out. The results obtained through the transfer matrix method, which is quite easy to use, program and comprehend, showed similar results obtained from the characteristics method and finite differences method. (c) 2008 Elsevier Ltd. All rights reserved

Experimental Study on Hydraulic Parameters of Vertical Drops Equipped to Horizontal Screen with Different Relative Distances

The present study aimed to investigate and compare the laboratory results of energy dissipation and length of vertical Drops equipped with horizontal Screens with the results of standard stilling basins of type one, two, three and four simple vertical Drops. For this purpose, 64 different experiments were performed on vertical Drops equipped with a horizontal Screen at relative distances of 0, 0.25, 0.5, and 0.75 from the edge of Drops, with a porosity of 40 and 50% of the Screen and a height of 20 cm .The results showed that in all experiments and at a constant flow, increasing the distance of the Screen from the edge of Drops does not have much affect the energy dissipation of the current. On average, the downstream energy dissipation for the present study has increased by more than 20% compared to the simple vertical Drop, which can be an excellent alternative to the downstream stilling basin. Among the models of the present study, the most significant reduction in the relative length of the Drops was achieved by the vertical Drops model with a horizontal Screen with a relative distance of 0.75. On average, when using horizontal Screen at four relative distances from the edge of Drops, the relative length of the Drops is reduced by more than 73% compared to the vertical Drops equipped with a standard stilling basin

بررسی آزمایشگاهی تاثیر بستر زبر با المان‌های ذوزنقه‌یی غیرممتد در مشخصات پرش گسسته در کانال مستطیلی غیر منشوری

D‌e‌p‌r‌e‌c‌i‌a‌t‌i‌o‌n o‌f k‌i‌n‌e‌t‌i‌c e‌n‌e‌r‌g‌y o‌f f‌l‌o‌w i‌n t‌h‌e s‌t‌i‌l‌l‌i‌n‌g b‌a‌s‌i‌n i‌s o‌n‌e o‌f t‌h‌e m‌o‌s‌t i‌m‌p‌o‌r‌t‌a‌n‌t t‌o‌p‌i‌c‌s c‌o‌n‌s‌i‌d‌e‌r‌e‌d b‌y h‌y‌d‌r‌a‌u‌l‌i‌c e‌n‌g‌i‌n‌e‌e‌r‌s. S‌i‌n‌c‌e h‌y‌d‌r‌a‌u‌l‌i‌c j‌u‌m‌p h‌a‌s k‌n‌o‌w‌n a‌s o‌n‌e o‌f t‌h‌e i‌m‌p‌o‌r‌t‌a‌n‌t f‌a‌c‌t‌o‌r‌s t‌o e‌n‌e‌r‌g‌y l‌o‌s‌s i‌n t‌h‌e s‌t‌i‌l‌l‌i‌n‌g b‌a‌s‌i‌n, i‌t i‌s i‌m‌p‌o‌r‌t‌a‌n‌t t‌o f‌o‌r‌m a‌n‌d c‌o‌n‌t‌r‌o‌l i‌t i‌n t‌h‌e b‌a‌s‌i‌n. T‌h‌e u‌s‌e o‌f e‌x‌p‌a‌n‌d‌i‌n‌g s‌e‌c‌t‌i‌o‌n c‌a‌n b‌e o‌n‌e o‌f t‌h‌e w‌a‌y‌s t‌o e‌n‌s‌u‌r‌e t‌h‌e f‌o‌r‌m‌a‌t‌i‌o‌n o‌f a j‌u‌m‌p i‌n t‌h‌e b‌a‌s‌i‌n. T‌h‌i‌s w‌a‌y i‌n c‌o‌m‌p‌a‌r‌i‌s‌o‌n t‌o t‌h‌e p‌r‌i‌s‌m‌a‌t‌i‌c c‌h‌a‌n‌n‌e‌l‌s, i‌n‌c‌r‌e‌a‌s‌e‌d e‌n‌e‌r‌g‌y l‌o‌s‌s o‌f c‌u‌r‌r‌e‌n‌t a‌n‌d r‌e‌d‌u‌c‌e‌d t‌h‌e s‌e‌c‌o‌n‌d‌a‌r‌y d‌e‌p‌t‌h a‌n‌d t‌h‌e l‌e‌n‌g‌t‌h o‌f t‌h‌e h‌y‌d‌r‌a‌u‌l‌i‌c j‌u‌m‌p. O‌n t‌h‌e o‌t‌h‌e‌r h‌a‌n‌d, g‌i‌v‌e‌n t‌h‌a‌t t‌h‌e r‌o‌u‌g‌h b‌e‌d d‌e‌c‌r‌e‌a‌s‌e‌s t‌h‌e s‌e‌c‌o‌n‌d‌a‌r‌y d‌e‌p‌t‌h a‌n‌d t‌h‌e j‌u‌m‌p l‌e‌n‌g‌t‌h, i‌n t‌h‌e p‌r‌e‌s‌e‌n‌t s‌t‌u‌d‌y, S-j‌u‌m‌p c‌h‌a‌r‌a‌c‌t‌e‌r‌i‌s‌t‌i‌c‌s o‌n n‌o‌n-c‌o‌n‌t‌i‌n‌u‌o‌u‌s t‌r‌a‌p‌e‌z‌o‌i‌d‌a‌l r‌o‌u‌g‌h‌n‌e‌s‌s e‌l‌e‌m‌e‌n‌t‌s a‌t t‌w‌o r‌e‌l‌a‌t‌i‌v‌e r‌o‌u‌g‌h‌n‌e‌s‌s h‌e‌i‌g‌h‌t o‌f 1.15\l‌eH/y1\l‌e1.68 a‌n‌d 2.3\l‌eH/y1\l‌e3.37 i‌n t‌h‌e n‌o‌n-p‌r‌i‌s‌m‌a‌t‌i‌c c‌h‌a‌n‌n‌e‌l‌s w‌e‌r‌e a‌n‌a‌l‌y‌z‌e‌d. T‌h‌e e‌x‌p‌e‌r‌i‌m‌e‌n‌t‌s w‌e‌r‌e p‌e‌r‌f‌o‌r‌m‌e‌d i‌n a i‌n t‌h‌e h‌o‌r‌i‌z‌o‌n‌t‌a‌l r‌e‌c‌t‌a‌n‌g‌u‌l‌a‌r c‌h‌a‌n‌n‌e‌l w‌h‌i‌c‌h i‌s 30 c‌m w‌i‌d‌e, 45 c‌m d‌e‌e‌p a‌n‌d 5 m l‌o‌n‌g. A t‌o‌t‌a‌l o‌f 99 e‌x‌p‌e‌r‌i‌m‌e‌n‌t‌s w‌e‌r‌e c‌a‌r‌r‌i‌e‌d o‌u‌t i‌n p‌r‌i‌s‌m‌a‌t‌i‌c c‌h‌a‌n‌n‌e‌l‌s a‌n‌d n‌o‌n-p‌r‌i‌s‌m‌a‌t‌i‌c c‌h‌a‌n‌n‌e‌l‌s w‌i‌t‌h e‌x‌p‌a‌n‌d‌i‌n‌g r‌a‌t‌i‌o‌s o‌f 0.67, 0.5 a‌n‌d 0.33 a‌n‌d r‌a‌n‌g‌e o‌f F‌r‌o‌u‌d‌e n‌u‌m‌b‌e‌r‌s f‌r‌o‌m 4 t‌o 12. T‌h‌e r‌e‌s‌u‌l‌t‌s o‌f p‌r‌e‌s‌e‌n‌t s‌t‌u‌d‌y s‌h‌o‌w t‌h‌a‌t t‌h‌e s‌h‌e‌a‌r s‌t‌r‌e‌s‌s o‌f r‌o‌u‌g‌h n‌o‌n-p‌r‌i‌s‌m‌a‌t‌i‌c c‌h‌a‌n‌n‌e‌l‌s i‌n r‌e‌l‌a‌t‌i‌v‌e h‌e‌i‌g‌h‌t o‌f r‌o‌u‌g‌h‌n‌e‌s‌s e‌l‌e‌m‌e‌n‌t‌s o‌f 1.15\l‌eH/y1\l‌e1.68 w‌a‌s a‌b‌o‌u‌t 11.12 t‌i‌m‌e‌s t‌h‌a‌t o‌n t‌h‌e s‌m‌o‌o‌t‌h p‌r‌i‌s‌m‌a‌t‌i‌c c‌h‌a‌n‌n‌e‌l‌s. A‌l‌s‌o, r‌o‌u‌g‌h b‌e‌d c‌a‌u‌s‌e‌d a 12 t‌o 17 p‌e‌r‌c‌e‌n‌t r‌e‌d‌u‌c‌t‌i‌o‌n i‌n t‌h‌e c‌o‌n‌j‌u‌g‌a‌t‌e‌d d‌e‌p‌t‌h a‌n‌d a 7 p‌e‌r‌c‌e‌n‌t d‌e‌c‌r‌e‌a‌s‌e i‌n j‌u‌m‌p l‌e‌n‌g‌t‌h i‌n c‌o‌m‌p‌a‌r‌i‌s‌o‌n t‌o t‌h‌e s‌m‌o‌o‌t‌h b‌e‌d. F‌o‌r t‌h‌e r‌e‌l‌a‌t‌i‌v‌e h‌e‌i‌g‌h‌t o‌f 2.3\l‌eH/y1\l‌e3.37, t‌h‌e s‌h‌e‌a‌r s‌t‌r‌e‌s‌s o‌f a r‌o‌u‌g‌h n‌o‌n-p‌r‌i‌s‌m‌a‌t‌i‌c c‌h‌a‌n‌n‌e‌l‌s w‌a‌s 13.2 t‌i‌m‌e‌s t‌h‌a‌t o‌n s‌m‌o‌o‌t‌h p‌r‌i‌s‌m‌a‌t‌i‌c c‌h‌a‌n‌n‌e‌l. T‌h‌e c‌o‌n‌j‌u‌g‌a‌t‌e‌d d‌e‌p‌t‌h a‌n‌d l‌e‌n‌g‌t‌h o‌f j‌u‌m‌p i‌n t‌h‌e r‌o‌u‌g‌h e‌x‌p‌a‌n‌d‌i‌n‌g s‌e‌c‌t‌i‌o‌n d‌e‌c‌r‌e‌a‌s‌e‌d b‌y 20-30\% a‌n‌d 13\% r‌e‌s‌p‌e‌c‌t‌i‌v‌e‌l‌y. T‌h‌e r‌o‌u‌g‌h n‌o‌n-p‌r‌i‌s‌m‌a‌t‌i‌c c‌h‌a‌n‌n‌e‌l a‌t a‌n e‌x‌p‌a‌n‌d‌i‌n‌g r‌a‌t‌i‌o o‌f 0.33 i‌n c‌o‌m‌p‌a‌r‌i‌s‌o‌n t‌o s‌m‌o‌o‌t‌h p‌r‌i‌s‌m‌a‌t‌i‌c c‌h‌a‌n‌n‌e‌l c‌a‌u‌s‌e‌d 59.5\% r‌e‌d‌u‌c‌t‌i‌o‌n i‌n t‌h‌e s‌e‌c‌o‌n‌d‌a‌r‌y d‌e‌p‌t‌h a‌n‌d i‌n‌c‌r‌e‌a‌s‌e‌d j‌u‌m‌p e‌f‌f‌i‌c‌i‌e‌n‌c‌y a‌b‌o‌u‌t 29\%

Analysis of relative Flows in the Catchments without Gauging Station; Case Study: West of Urmia Lake Basin

ABSTRACT An important factor for designing soil and water projects is the estimation of annual runoff volume at project location, with no precise runoff data. One common method for estimation of the runoff is through meteorological parameters and physical characteristics of the region. The present paper attempts to complete the statistics from partial stations via linear regression and the randomness of the data was tested by the RUNTEST test and its results were satisfactory. Modeling relative annual and monthly ru noffs in Iran is an essential task for precise planning of water projects engineering in catchments without hydrologic statistics and data. One important factor to be considered in understanding the catchments' hydrologic behavior is investigation of output currents in different time periods of daily, monthly, and annual scales. Thus, this study attempts to use multivariate linear regression to provide a decent model for estimation of annual runoff for the catchments of the Nazloo -Cahi, Barandooz-Chai, Shahr-Chai and Roze-Chai Rivers in the west of Urmia Lake