An Experimental Investigation into the Effect of Curve Radius on the Discharge Coefficient in Curved-Linear and Curved-Labyrinth Weirs with a Triangular Plan

Authors

Heidarnejad, M. 2. Department of Water Science Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.

Kamanbedast, A. 2. Department of Water Science Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.

Masjedi, A. R. 2. Department of Water Science Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.

Monjezi, R. 1. Department of Water Science Engineering, Khouzestan Science and Research Branch, Islamic Azad University, Ahvaz, Iran., 2. Department of Water Science Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.

Pourmohammadi, M. H. 3. Department of Water Science Engineering, Shoushtar Branch, Islamic Azad University, Shoushtar, Iran.

Abstract:

Nonlinear weirs are regarded as important hydraulic structures for water level adjustment and flow control in channels, rivers and dam reservoirs. One example of non-linear weirs is shaped as curved-zigzag. The crest axis of these weirs is non-linear. At a given width, the crest length is greater than that of the conventional linear weirs. Thus, they achieve a higher flow rate for an identical hydraulic load. This research experimentally focused on the discharge coefficient and flow rate of curved weirs with three different curve radii in two triangular linear and zigzag shapes. The discharge coefficients of these weirs were comparatively explored in terms of the hydraulic performance as a function of the total hydraulic load to weir crest height ratio (hd/P) and curvature angle (θ) (or curve radius). The results indicated that for the same hydraulic load, the increase of θ (the decrease in curve radius) led to a lower discharge coefficient; this was first because of the increased topical rise of water level, and then the more indirect path with a greater curvature through which the flow had to transport. Both factors could negatively affect the water discharge coefficient. In practice, the runoff coefficient at a weir with a curve radius of R/w=1.25 was approximately 8.5% greater than that of a weir with a curve radius of R/w=0.75 under a hydraulic load of 0.2.

Upgrade to premium to download articles

Already have an account?login

similar resources

Numerical study of flow of labyrinth weir with triangular and curved plan form using Fluent software

Labyrinth weirs have not a straight crest in the perpendicular direction to the flow. The plan view of the weir consists of multiple and broken linear crests that cause the increase of its effective length. The advantages of this type of weirs are higher discharge capacity, easy aeration as well as low fluctuations of water surface at the weir upstream. This paper deals with the simulation of t...

full text

on the effect of linear & non-linear texts on students comprehension and recalling

چکیده ندارد.

15 صفحه اول

Study of Duckbill Weir with Triangular and Curved Plan Form

Constructing of control structures, like dams, change temporal and spatial unequal distribution of water ,and also play an effective role in reduce or eliminate of damage that caused by floods. So reservoir dam’s effect on floods discharges reduction must be determined. In this study the rain Information and flood hydrographs were used to check the flood routing for previous period of Maroon da...

full text

an investigation of the impact of self monitoring on langauge teachers motivational practice and its effect on learners motivation

the central purpose of this study was to conduct a case study about the role of self monitoring in teacher’s use of motivational strategies. furthermore it focused on how these strategies affected students’ motivational behavior. although many studies have been done to investigate teachers’ motivational strategies use (cheng & d?rnyei, 2007; d?rnyei & csizer, 1998; green, 2001, guilloteaux & d?...