## 다양한 수력학적 및 기하학적 조건에서 아래에 반원형 게이트가 결합된 두 개의 직사각형 복합 웨어의 배수 계수

## ABSTRACT

Two-component composite hydraulic structures are commonly employed in irrigation systems. The first component, responsible for managing the overflow, is represented by a weir consisting of two rectangles. The second component, responsible for regulating the underflow, is represented by a semicircular gate. Both components are essential for measuring, directing, and controlling the flow. In this study, we experimentally investigated the flow through a combined two-rectangle sharp-crested weir with a semicircular gate placed across the channel as a control structure. The upper rectangle of the weir has a width of 20 cm, while the lower rectangle has varying widths (W2 ) of 5, 7, and 9 cm and depths (z) of 6, 9, and 11 cm. Additionally, three different values were considered for the gate diameter (d), namely 8, 12, and 15 cm. These dimensions were tested interchangeably, including a weir without a gate (d = 0), under different water head conditions. The results indicate that the discharge passing through the combined structure of the two rectangles and the gate is significantly affected by the weir and gate dimensions. After analyzing the data, empirical formulas were developed to predict the discharge coefficient (Cd ) of the combined structure. It is important to note that the analysis and results presented in this study are limited to the range of data that were tested.

2성분 복합 수력 구조물은 일반적으로 관개 시스템에 사용됩니다. 오버플로 관리를 담당하는 첫 번째 구성 요소는 두 개의 직사각형으로 구성된 웨어로 표시됩니다.

언더플로우 조절을 담당하는 두 번째 구성 요소는 반원형 게이트로 표시됩니다. 두 구성 요소 모두 흐름을 측정, 지시 및 제어하는 데 필수적입니다. 본 연구에서 우리는 제어 구조로 수로를 가로질러 배치된 반원형 게이트를 갖춘 결합된 두 개의 직사각형 뾰족한 둑을 통한 흐름을 실험적으로 조사했습니다.

웨어의 위쪽 직사각형은 폭이 20cm인 반면, 아래쪽 직사각형은 5, 7, 9cm의 다양한 폭(W2)과 6, 9, 11cm의 깊이(z)를 갖습니다. 또한 게이트 직경(d)에 대해 8, 12, 15cm의 세 가지 다른 값이 고려되었습니다.

이러한 치수는 게이트가 없는 둑(d = 0)을 포함하여 다양한 수두 조건에서 상호 교환적으로 테스트되었습니다. 결과는 두 개의 직사각형과 게이트가 결합된 구조를 통과하는 방전이 위어와 게이트 크기에 크게 영향을 받는다는 것을 나타냅니다.

데이터를 분석한 후, 결합구조물의 유출계수(Cd)를 예측하기 위한 실험식을 개발하였다. 본 연구에서 제시된 분석 및 결과는 테스트된 데이터 범위에 국한된다는 점에 유의하는 것이 중요합니다.

## Keywords

combound weir; semicircular gates; discharge coefficient; combined structure; open channels;

discharge measurement

## REFERENCES

[1] S. S. Ibrahim, R. A. Jafer, and B. M. A. S. Ali, “An Experimental Study

of a Combined Oblique Cylindrical Weir and Gate Structure,”

Engineering, Technology & Applied Science Research, vol. 13, no. 2,

pp. 10483–10488, Apr. 2023, https://doi.org/10.48084/etasr.5646.

[2] F. Rooniyan, “The Effect of Confluence Angle on the Flow Pattern at a

Rectangular Open Channel,” Engineering, Technology & Applied

Science Research, vol. 4, no. 1, pp. 576–580, Feb. 2014,

https://doi.org/10.48084/etasr.395.

[3] A. S. Kote and P. B. Nangare, “Hydraulic Model Investigation on

Stepped Spillway’s Plain and Slotted Roller Bucket,” Engineering,

Technology & Applied Science Research, vol. 9, no. 4, pp. 4419–4422,

Aug. 2019, https://doi.org/10.48084/etasr.2837.

[4] S. M. Kori, A. A. Mahessar, M. Channa, A. A. Memon, and A. R. Kori,

“Study of Flow Characteristics Over a Rounded Edge Drop Structure in

Open Channel,” Engineering, Technology & Applied Science Research,

vol. 9, no. 3, pp. 4136–4139, Jun. 2019, https://doi.org/

10.48084/etasr.2584.

[5] F. Granata, F. Di Nunno, R. Gargano, G. de Marinis, “Equivalent

Discharge Coefficient of Side Weirs in Circular Channel—A Lazy

Machine Learning Approach,” Water, vol. 11, no.11, 2019, Art. no.

2406, https://doi.org/10.3390/w11112406.

[6] S. Salehi and A. H. Azimi, “Discharge Characteristics of Weir-Orifice

and Weir-Gate Structures,” Journal of Irrigation and Drainage

Engineering, vol. 145, no. 11, Nov. 2019, Art. no. 04019025,

https://doi.org/10.1061/(ASCE)IR.1943-4774.0001421.

[7] M. G. Bos, Ed., Discharge Measurement Structures. Wageningen, The

Netherlands: International Institute for Land Reclamation and

Improvement, 1989.

[8] S. Emami, J. Parsa, H. Emami, A. Abbaspour, “An ISaDE algorithm

combined with support vector regression for estimating discharge

coefficient of W-planform weirs,” Water Supply, vol. 21, no.7, pp.

3459–3476, 2021, https://doi.org/10.2166/ws.2021.112.

[9] A. B. Altan-Sakarya, M. A. Kokpinar, and A. Duru, “Numerical

modelling of contracted sharp-crested weirs and combined weir and gate

systems,” Irrigation and Drainage, vol. 69, no. 4, pp. 854–864, 2020,

https://doi.org/10.1002/ird.2468.

[10] P. Ackers, W. R. White, J. A. Perkins, A. J. M. Harrison, Weirs and

Flumes for Flow Measurement, New York, NY, USA: Wiley, 1978.

[11] A. Alhamid, D. Husain, and A. Negm, “Discharge equation for

simultaneous flow over rectangular weirs and below inverted triangular

weirs,” Arab Gulf Journal of Scientific Research, vol. 14, no. 3, pp. 595–

607, Dec. 1996.

[12] N. Rajaratnam and K. Subramanya, “Flow Equation for the Sluice Gate,”

Journal of the Irrigation and Drainage Division, vol. 93, no. 3, pp. 167–

186, Sep. 1967, https://doi.org/10.1061/JRCEA4.0000503.

[13] A. Zahiri, H. Md. Azamathulla, and S. Bagheri, “Discharge coefficient

for compound sharp crested side weirs in subcritical flow conditions,”

Journal of Hydrology, vol. 480, pp. 162–166, Feb. 2013,

https://doi.org/10.1016/j.jhydrol.2012.12.022.

[14] S. A. Sarhan and S. A. Jalil, “Analysis of Simulation Outputs for the

Mutual Effect of Flow in Weir and Gate System,” Journal of University

of Babylon for Engineering Sciences, vol. 26, no. 6, pp. 48–59, Apr.

2018, https://doi.org/10.29196/jubes.v26i6.1050.

[15] M. Muhammad and S. Abdullahi, “Experimental Study of Flow over

Sharp Crested Rectangular-Triangular Weir Models,” in Nigeria

Engineering Conference Proceedings, Zaria – Nigeria, Jan. 2014, pp.

34–45.

[16] M. Piratheepan, N. E. F. Winston, and K. P. P. Pathirana, “Discharge

Measurements in Open Channels using Compound Sharp-Crested

Weirs,” vol. 40, no. 3, pp. 31-38, Jul. 2007,

https://doi.org/10.4038/engineer.v40i3.7144.

[17] H. A. Hayawi, A. A. Yahia, G. A. Hayawi, “Free combined flow over a

triangular weir and under rectangular gate,” Damascus University

Journal, vol. 24, no. 1, pp. 9–22, 2008.

[18] A.-A. M. Negm, A. M. Al-Brahim, and A. A. Alhamid, “Combined-free

flow over weirs and below gates,” Journal of Hydraulic Research, vol.

40, no. 3, pp. 359–365, May 2002, https://doi.org/10.1080/

00221680209499950.

[19] A. A. Alhamid, A.-A. M. Negm, and A. M. Al-Brahim, “Discharge

Equation for Proposed Self-cleaning Device,” Journal of King Saud

University – Engineering Sciences, vol. 9, no. 1, pp. 13–23, Jan. 1997,

https://doi.org/10.1016/S1018-3639(18)30664-0.

[20] S. I. Khassaf and M. Habeeb, “Experimental Investigation for Flow

Through Combined Trapezoidal Weir and Rectangular Gate,”

International Journal of Scientific & Engineering Research, vol. 5, no.

4, pp. 809–814, 2014.

[21] A. A. G. Alniami, D. G. A. M. Hayawi, and H. A. M. Hayawi,

“Coefficient Of Discharge For A Combined Hydraulic Measuring

Device,” Al-Rafidain Engineering Journal, vol. 17, no. 6, pp. 92–100,

Dec. 2009, https://doi.org/10.33899/rengj.2009.43616.

[22] J. M. Samani and M. Mazaheri, “Combined Flow over Weir and under

Gate,” Journal of Hydraulic Engineering, vol. 135, no. 3, pp. 224–227,

Mar. 2009, https://doi.org/10.1061/(ASCE)0733-9429(2009)135:3(224).

[23] B. Balouchi and G. Rakhshandehroo, “Using Physical and Soft

Computing Models to Evaluate Discharge Coefficient for Combined

Weir–Gate Structures Under Free Flow Conditions,” Iranian Journal of

Science and Technology, Transactions of Civil Engineering, vol. 42, no.

4, pp. 427–438, Dec. 2018, https://doi.org/10.1007/s40996-018-0117-0.

[24] M. A. R. Eltoukhy, F. S. Abdelhaleem, T. H. Nasralla, S. Shaban,

“Effect of Compound Weir and below Circular Gate Geometric

Characteristics on its Discharge Coefficient,” International Journal of

Scientific & Engineering Research, Vol. vol. 11, no. 10, pp. 1115–1130,

Oct. 2020.

[25] C. E. Kindsvater and R. W. Carter, “Discharge Characteristics of

Rectangular Thin-Plate Weirs,” Transactions of the American Society of

Civil Engineers, vol. 124, no. 1, pp. 772–801, Jan. 1959,

https://doi.org/10.1061/TACEAT.0007696.

[26] H. R. Henry, “Discussion of Diffusion of Submerged Jets,” Transactions

of ASCE, vol. 115, no. 1, pp. 687–694, Jan. 1950.