Numerical simulation of mud-flows impacting structures
The study of the interaction of mud-flows with obstacles is important to define inundation zones in urban areas and to design the possible structural countermeasures. The paper numerically investigates the impact of a mud-flow on rigid obstacles to evaluate the force acting on them using two different depth-integrated theoretical models, Single-Phase Model (SPM) and Two-Phase Model (TPM), to compare their performance and limits. In the first one the water-sediment mixture is represented as a homogeneous continuum described by a shear-thinning power-law rheology. Alternatively, the two-phase model proposed by Di Cristo et al in 2016 is used, which separately accounts for the liquid and solid phases. The considered test cases are represented by a 1D landslide flowing on a steep slope impacting on a rigid wall and a 2D mud dam-break flowing on a horizontal bottom in presence of single and multiple rigid obstacles. In the 1D test case, characterized by a very steep slope, the Two-Phase Model predicts the separation between the two phases with a significant longitudinal variation of the solid concentration. In this case the results indicate appreciable differences between the two models in the estimation of both the wave celerity and the magnitude of the impact, with an overestimation of the peak force when using the Single-Phase Model. In the 2D test-cases, where the liquid and solid phases remain mixed, even if the flow fields predicted by the two models present some differences, the essential features of the interaction with the obstacles, along with the maximum impact force, are comparable.
KeywordsMud-Flow Impact force Two-phase model Power-law
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The work described in the present paper was realized in the framework of the project MISALVA, financed by the Italian Minister of the Environment, Land Protection and Sea. CUP H36C18000970005.
- Chanson H, Jarny S, Coussot P (2006) Dam Break Wave of Thixotropic Fluid. Journal of Hydraulic Engineering 132 (3): 280–293. https://doi.org/10.1061/(asce)0733-9429(2006)132:3(280) Google Scholar
- Di Cristo C, Greco M, Iervolino M, Leopardi A, Vacca A (2016) Twodimensional two-phase depth-integrated model for transients over mobile bed. Journal of Hydraulic Engineering 142(2), 04015043. https://doi.org/10.1061/(ASCE)HY.1943-7900.0001024 Google Scholar
- Dressler RF (1952) Hydraulic resistance effect upon the dam-break functions. Journal of Research of the National Bureau Standards 49(3): 217–225.Google Scholar
- Faug T (2015) Depth-average analytical solution for free-surface granular flow impacting rigid walls down inclines. Physical Review E 92(6). https://doi.org/10.1103/PhysRevE.9292.062310
- Gori F, Boghi A (2011) Two new differential equations of turbulent dissipation rate and apparent viscosity for non-newtonian fluids. International Communications in Heat and Mass Transfer 38(6): 696–703. https://doi.org/10.1016/j.icheatmasstransfer.2011.03.003 Google Scholar
- Gori F, Boghi A (2012) A three dimensional exact equation for the turbulent dissipation rate of Generalised Newtonian Fluids. International Communications in Heat and Mass Transfer 39(4): 477–485. https://doi.org/10.1016/j.icheatmasstransfer.2012.02.010 Google Scholar
- Greco M, Iervolino M, Vacca A, et al. (2012b) Two-phase modelling of total sediment load in fast geomorphic transients. River Flow 2012, Proc., Int. Conf. on Fluvial Hydraulics, 1, Colegio de Ingenieros Civiles de Costa Rica (CiC): 643–648.Google Scholar
- Iervolino M, Carotenuto C, Gisonni C, et al. (2017) Impact Forces of a Supercritical Flow of a Shear Thinning Slurry Against an Obstacle. In: Mikoš M, Casagli N, Yin Y, et al. (eds), Advancing Culture of Living with Landslides. WLF 2017. Springer, https://doi.org/10.1007/978-3-319-53485-5_46 Google Scholar
- Jóhannesson T, Gauer P, Issler P, et al. (2009) The design of avalanche protection dams-Recent practical and theoretical developments. Project Report EUR23339. Climate Change and Natural Hazard Research Area. Series2. European Commission (Available online at: https://hal.archives-ouvertes.fr/hal-00575782/)Google Scholar
- Leopardi A, Oliveri E, Greco M (2002) Two-dimensional modeling of flood to map risk prone areas. Journal of Water Resources Planning and Management 128(3): 168–178. https://doi.org/10.1061/(ASCE)0733-9496(2002)128:3(168) Google Scholar
- O’Brien JS, Julien PY, Fullerton WT (1993) Two-dimensional water flood and mudflow simulation. Journal of Hydraulic Engineering 119(2): 244–261. https://doi.org/10.1061/(ASCE)0733-9429(1993)119:2(244) Google Scholar
- Shige-eda M, Akiyama J (2003) Numerical and experimental study on two-dimensional flood flows with and without structures. Journal of Hydraulic Engineering 129(10): 817–821. https://doi.org/10.1061/(ASCE)0733-9429(2003)129:10(817) Google Scholar
- Takahashi T (2007) Debris Flow: Mechanics, Prediction and Countermeasures. Taylor and Francis, New York, USA.Google Scholar
- Tiberghien D, Laigle D, Naaim M, et al. (2007) Experimental investigation of interaction between mudflow and on obstacle. Proceeding of the International Conference on Debris-Flow Hazard Mitigation: Mechanics, Prediction and Assessment, Chengdu. China. pp 281–292.Google Scholar
- Turnbull B, Bowman ET, McElwaine JN (2015) Debris flows: experiments and modelling. Comptes Rendus Physique 16(1): 86–96.Google Scholar
- Wang Y, Williams KC, Jones MG, et al. (2010) CFD simulation of gas-solid flow in dense phase bypass pneumatic conveying using the Euler-Euler model. Applied Mechanics and Materials 26-28: 1190–1194. https://doi.org/10.4028/www.scientific.net/AMM.26-28.1190 Google Scholar
- Wu W, Wang SS-Y (2007) One dimensional modeling of dam-break flow over movable beds. Journal of Hydraulic Engineering 133(1): 48–58. https://doi.org/10.1061/(ASCE)0733-9429(2007)133:1(48) Google Scholar
- Zhang X, Bai Y, Ng CO (2010) Rheological Properties of Some Marine Muds Dredged from China Coasts. Proceedings of the 28 International Offshore and Polar Engineering Conference, Beijing, China. pp 455–461.Google Scholar