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Numerical Simulation and Geometric Optimization of the Stepped Spillway of Jare Dam Using a Multi Objective Genetic Algorithm | ||
| تحقیقات مهندسی سازه های آبیاری و زهکشی | ||
| Volume 21, Issue 81, March 2021, Pages 83-100 PDF (757.34 K) | ||
| Document Type: Original Article | ||
| DOI: 10.22092/idser.2021.352524.1445 | ||
| Authors | ||
| mohammad hadi fattahi* 1; Ali Sinaee2 | ||
| 1Assistant professor , Civil engineering Dept., Marvdasht Branch, Islamic azad university, Marvdasht, Iran. | ||
| 2Civil Eng. Dept,, Marvdasht Islamic Azad University | ||
| Abstract | ||
| Introduction: Concerning the importance of water saving in Iran, as an arid and semi-arid country, dam construction plays a crucial role in water resources management. Spillways are one of the most important components of a dam. They are different in shape and function. Stepped spillway is one of the most designed and operated ones. Numerical simulation of the stepped spillway of Jare dam using FLOW 3D software and the geometric optimization of the steps' dimension using the multi-objective genetic algorithm is investigated in this research. The idea of using stepped spillways goes back to 3500 years ago (James et al., 2001). The oldest stepped spillway built in Iran has been recorded from 600 years ago. Studying the geometric features of stepped spillways in order to optimize the size and dimension of steps has also been the issue of interest for researchers (Chanson, 1996 and 20021; Pegram et al., 1999; Ferrari, 2010). Methodology: An experimental model of Stepped spillway of Jare Dam has been set up first in order to calibrate and verify the numerical model. Flow 3D software is applied for numeric simulation of the spillway and the multi objective genetic algorithm (NSGAII) is implemented to optimize the geometric dimensions. Calibration of the model has done after introducing the experimental models' geometry to FLOW 3D. Comparing the velocity data recorded by the numerical model and the experimental velocity data, the software has been verified. Turbulence modeling is the construction and use of a mathematical model to predict the effects of turbulence. Turbulence models are simplified constitutive equations that predict the statistical evolution of turbulent flows. K-epsilon (k-ε) turbulence model is a practical model to simulate the mean flow characteristics for turbulent flow conditions. It is a two-equation model which gives a general description of turbulence condition of the ambient flow by means of two transport equations (PDEs). The RNG model was developed using Re-Normalisation Group (RNG) methods to renormalize the Navier-Stokes equations, to monitor the effects of smaller scales of motion especially those of vertex movements. In k-ε model the eddy viscosity is determined from a single turbulence length scale, so the diffusion seen in the calculated turbulence is that which occurs only at the specified scale, although in real physical situations, all scales of motion will contribute to the turbulent diffusion especially those with more curvature streams. RNG turbulent model, as mathematical method that can be utilized to extract turbulence similar to the k- ε, results in a modified form of the epsilon equation. We have implemented both methods to simulate the turbulancd in the flow over the stepped spillway and to compare the effectiveness of both models when flow is dealing with a complicated solid as the Jare Dam spillway. Five different types have been considered for the geometry of the stepped spillway. Numbers of steps are designated 3 to 7 steps and are earmarked as the algorithm constrains. The variables are then defined and the fitness function of the algorithm is extracted. The multi objective genetic algorithm is then coded in MATLAB. In optimization procedure the geometric features including width, height and the number of steps in each five discussed type are calculated. Results and Discussion: Velocity results using two turbulent models, RNG and K-ε, have been calculated separately. The results of the RNG model depict better match in accordance to the physical model's velocity data with less than 10 percent error. In optimization procedure the stepped spillway with 4 steps, 0.072m width (1:5) and 0.0665m height (1:5), is considered as the most optimum choice regarding the economic and hydraulic concerns. Conclusion: Flow 3D software simulated the flow over the stepped spillway of Jare Dam quite acceptable. The simulating model depicted the most accuracy using the RNG turbulent model and the multi objective genetic algorithm used (NSGAII) suggested the 4 steps spillway as the most economic and functional choice for Jare stepped spillway. | ||
| Keywords | ||
| Stepped spillway; FLOW 3D; RNG; K-ε Economic assessment | ||
| References | ||
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Ashrafi, F. (2009). Numerical Analysis Flow on Stepped Spillway Using Flow3D and CCHE2D Software. Kerman. Shahid Bahonar. M.Sc. Thesis. Bozorghaddad, O. Mirmomeni, M. and Marino, M. (2010). Optimal Design of Environment System, stepped spillways using The HBMO Algorithm. Civil Engineering, 1 (27):81-94. Bozorghaddad, O. Sharifi, E. and Naderi, M. (2005). Optimum Design of Stepped spillways using Genetic Algorithm. Proceedings of the 6th WSEAS Int. Conf. on EVOLUTIONARY COMPUTING, Lisbon, Portugal, 325-331. Chanson H. (1995). Hydraulic design of stepped cascade, channels, weirs and spillways. Pergamon, Oxford, UK. Chanson, H. (1996). Prediction of the transition nappe/skimming flow on a stepped channel. Journal of Hydraulic Research, 30 (34).Chanson, H. (2001). A transition flow regime on stepped spillways: the facts. Proceeding 29th LAHR congress, Beijing, China. Chadgani, A. and Khosrojerdi, A. (2012). Hydraulic Analysis of Flow on Stepped Spillways Using Software Flow3D. 9th International River Engineering Conference. Shahid Chamran University. Fathi, A. (2009). Survey of Effect of Downstream Crest Chute Slope on the Natural Air Entrainment Point in Skimming Flow in Stepped Spillway. Journal of Water and Solid. Vol 23. No 3. Ferrari, A. (2010). Simulation of free surface flow over a sharp-crested weir. Advances in Water Resources, 3 (33): 270–276. James, C.S., Ohtsu, I., Yasuda, Y., Takahasi, M., Tatewar, P., Ingle, N. and Porey, D. (2001). Discussion of 'onset of skimming flow on stepped spillways' by Chamani, M.R., Rajaratnam, N. Journal of Hydraulic Eng., 127 (6): 519- 525. Mansori. (2013). Analysis Flow on Stepped Spillway of Siahbishe dam with Flow3D. 7TH Congress Civil Engineering. Zahedan. Shahid Nikbakht University. Morovati, Kh., Eghbalzadeh, A., Soori S. (2016). Numerical Study of Energy Dissipation of Pooled Stepped Spillways. Civil Engineering Journal Vol. 2, No. 5 Pegram, GS., Officer, AK. And Mottram, SR. (1999). Hydraulic of skimming flow on modeled stepped spillways. Journal of Hydraulic Engineering, 500-510. Sarvarian J., Mamizadeh J. (2019). Development a two-objective simulation - optimization model to the optimal design of geometric dimensions and slope of the stepped spillway of upstream Siah-Bisheh Dam using NSGA-II algorithm. Iranian Journal of Soil & Water Rsearch, Vol. 51 (2): 469-478. Shoja F., Salmasi F., Farsadizadeh D., Nazemi A.H. (2011). Optimal Design of Stepped Spillways for Maximizing Energy Dissipation Using Genetic Algorithm. Sohrabipour, N. (2002). Survey energy dissipation on stepped spillways. Kerman, Shahid Bahonar University. Water research Institute (2009). Final report: Hydraulic model of Jare Dam flood drainage system. Khozetan water and Power Corporation. | ||
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