Ani ve Kademeli Kasılmalarda Histerik Davranışın Kalan Enerji ve Akış Rejimi Üzerindeki Etkisi Üzerine

Öz

Mevcut çalışmada, kanal genişliğinin kesitsel daralmaları da dahil olmak üzere, bitişik yapılara yakın bir kanalda meydana gelebilecek süperkritik akışın histerik davranışı deneysel olarak incelenmiştir. 5, 10 ve 15 cm'lik üç ani daralma ve 15 cm'lik kademeli bir daralma kullanılmıştır. Debiler 250 ila 600 Lit/dakika arasında değişmiştir. Bu koşullar bir laboratuvar su kanalında ayarlanmıştır; önce başlangıç ​​debisinde bir artış, ardından ikincil debide bir azalma vardır. Sonuçlar, debiyi artırıp sonra azaltarak, aynı laboratuvar koşullarında iki farklı akış davranışının gözlendiğini göstermektedir. Sonuçlar, ani daralma oranının artmasıyla birlikte, bağıl derinlik değerlerinin azaldığını, böylece başlangıç ​​debisinde bu derinliklerin alt kritik rejimi, ikincil debide ise bazı deşarjlarda histerezis oluşumuyla birlikte süperkritik rejimi gösterdiğini göstermiştir. Ayrıca, histerik davranış bağıl artık enerjiyi artırır. Aniden 15 cm'lik daralmayla su altı hidrolik sıçramalarının oluşması histerezis eksikliğine neden oldu.

Anahtar Kelimeler

• Histerezis;
• Akış rejimleri
• Ani ve kademeli daralma
• Bağıl artık enerji
• Bağıl derinlik

On the Effect of Hysteretic Behavior on the Residual Energy and Flow Regime in the Sudden and Gradual Contraction

Öz

In the present study, the hysteretic behavior of supercritical flow that can occur in a channel near adjacent structures, including cross-sectional contractions of the channel width, has been investigated experimentally. Three sudden contracting of 5, 10 and 15 cm and a gradual contraction of 15 cm have been used. The flow rates ranged from 250 to 600 Lit/min. These conditions are set within a laboratory flume; first there is an increase in the initial flow and then a decrease in secondary flow. The results show that by increasing and then decreasing the flowrate, two different behaviors of flow are observed with the same laboratory conditions. The results showed that with increasing the rate of sudden contracting, the values of relative depths decrease, so that in the initial flow these depths indicate a subcritical regime and in the secondary flow with the formation of hysteresis in some discharges indicate a supercritical regime. Also, hysteretic behavior increases the relative residual energy. With the sudden contraction of 15 cm, the formation of submerged hydraulic jumps resulted in a lack of hysteresis.

Anahtar Kelimeler

• Hysteresis
• Flow regimes
• Sudden and gradual contraction
• Relative residual energy
• Relative depth

Kaynakça

1. [1] Abecasis, F.M., and Quintela, AC. 1964. Hysteresis in steady free-surface flow. Water Power. 16, 147–151.
2. [2] Baines, P.G., and Davies, P.A. 1980. Laboratory studies of topographic effects in rotating and /or stratified fluids. In: WMO Orographic Effects in Planetary Flows. 1, 233–299.
3. [3] Austria, P.M. 1987. Catastrophe model for the forced hydraulic jump. Journal of Hydraulic research. 25, 269–280.
4. [4] Lawrence, G.A. 1987. Steady flow over an obstacle. Journal of Hydraulic Engineering. 113, 981-991.
5. [5] Baines, P.G., and Whitehead, J.A. 2003. On multiple states in single-layer flows. Physics of Fluids. 15, 298-307.
6. [6] Defina, A., and Susin, F.M. 2006. Multiple states in open channel flow. Vorticity and Turbulence Effects in Fluid Structures Interactions. 105-130.
7. [7] Akers, B., and Bokhove, O. 2008. Hydraulic flow through a channel contraction: Multiple steady states. Physics of Fluids. 20, 1-15.
8. [8] Defina, A., Viero, D.P. 2010. Open channel flow through a linear contraction. Physics of Fluids. 22: 1-12.

9. [9] Sadeghfam, S., Khatibi, R., Hassanzadeh, Y., Daneshfaraz, R., Ghorbani, M.A. 2017. Forced hydraulic jumps described by classic hydraulic equations reproducing cusp catastrophe features. Arabian Journal for Science and Engineering. 42, 4169-4179.
10. [10] Daneshfaraz, R., Aminvash, E., Ebadzadeh, P. 2023a. Experimental study of the effect of different sill geometry on hysteretic behavior of supercritical regime. Irrigation Sciences and Engineering. 46, 1-15 [In Persian].
11. [11] Viero, D.P., and Defina, A. 2018. Multiple states in the flow through a sluice gate. Journal of Hydraulic Research. 57, 39-50.
12. [12] Daneshfaraz, R., Aminvash, E., Sadeghfam, S. 2023b. Laboratory and theoretical study of hysteretic effects on hydraulic characteristics of flow at the site of smooth to rough bed conversion. Iranian Journal of Science and Technology, Transactions of Civil Engineering. 47, 3975-3987.
13. [13] Aminvash, E., Daneshfaraz, R., Sadeghfam, S., Mousavi, S. B. 2024. Laboratory investigation of the effect of hysteresis phenomenon of supercritical flow on the rough bed on the relative residual energy parameter. Journal of Hydraulic Structures. 10, 82-92.
14. [14] Daneshfaraz, R., Aminvash, E., Najibi, A. 2022. Experimental study of hysteretic behavior of supercritical regime on hydraulic parameters of flow against gabion contraction. Iranian Journal of Soil and Water Research. 53, 33-44 [In Persian].
15. [15] Aminvash, E., Daneshfaraz, R., Sume, V., Sadeghfam, S., Abraham, J. 2024. On the Multiple Steady Flow States in Spindle Shaped Geometry of Bridge Foundations. Journal of Applied Fluid Mechanics. 18(1), 1-15.
16. [16]. Daneshfaraz, R., Aminvash, E., Esmaeli, R., Sadeghfam, S., Abraham, J. 2020. Experimental and numerical investigation for energy dissipation of supercritical flow in sudden contractions. Journal of groundwater science and engineering. 8, 396-406.
17. [17] Daneshfaraz, R., Aminvash, E., Ghaderi, A., Kuriqi, A., Abraham, J. 2021. Three-dimensional investigation of hydraulic properties of vertical drop in the presence of step and grid dissipators. Symmetry. 13, 895.
18. [18] Abbaszadeh, H., Daneshfaraz, R., Sume, V., Abraham, J. 2024. Experimental investigation and application of soft computing models for predicting flow energy loss in arc-shaped constrictions. AQUA—Water Infrastructure, Ecosystems and Society. 73, 637-661.