Computational Determination of Air Valves Capacity Using CFD Techniques

[EN] The analysis of transient flow is necessary to design adequate protection systems that support the oscillations of pressure produced in the operation of motor elements and regulation. Air valves are generally used in pressurized water pipes to manage the air inside them. Under certain circumstances, they can be used as an indirect control mechanism of the hydraulic transient. Unfortunately, one of the major limitations is the reliability of information provided by manufacturers and vendors, which is why experimental trials are usually used to characterize such devices. The realization of these tests is not simple since they require an enormous volume of previously stored air to be used in such experiments. Additionally, the costs are expensive. Consequently, it is necessary to develop models that represent the behaviour of these devices. Although computational fluid dynamics (CFD) techniques cannot completely replace measurements, the amount of experimentation and the overall cost can be reduced significantly. This work approaches the characterization of air valves using CFD techniques, including some experimental tests to calibrate and validate the results. A mesh convergence analysis was made. The results show how the CFD models are an efficient alternative to represent the behavior of air valves during the entry and exit of air to the system, implying a better knowledge of the system to improve it.This research was funded by the Program Fondecyt Regular, grant number 1180660.García-Todolí, S.; Iglesias Rey, PL.; Mora Melia, D.; Martínez-Solano, FJ.; Fuertes-Miquel, VS. (2018). Computational Determination of Air Valves Capacity Using CFD Techniques. Water. 10(10):1-16. https://doi.org/10.3390/w101014331161010Liou, C. P., & Hunt, W. A. (1996). Filling of Pipelines with Undulating Elevation Profiles. Journal of Hydraulic Engineering, 122(10), 534-539. doi:10.1061/(asce)0733-9429(1996)122:10(534)Zhou, F., Hicks, F. E., & Steffler, P. M. (2002). Transient Flow in a Rapidly Filling Horizontal Pipe Containing Trapped Air. Journal of Hydraulic Engineering, 128(6), 625-634. doi:10.1061/(asce)0733-9429(2002)128:6(625)Laanearu, J., Annus, I., Koppel, T., Bergant, A., Vučković, S., Hou, Q., … van’t Westende, J. M. C. (2012). Emptying of Large-Scale Pipeline by Pressurized Air. Journal of Hydraulic Engineering, 138(12), 1090-1100. doi:10.1061/(asce)hy.1943-7900.0000631Apollonio, C., Balacco, G., Fontana, N., Giugni, M., Marini, G., & Piccinni, A. (2016). Hydraulic Transients Caused by Air Expulsion During Rapid Filling of Undulating Pipelines. Water, 8(1), 25. doi:10.3390/w8010025Zhou, F., Hicks, F. E., & Steffler, P. M. (2002). Observations of Air–Water Interaction in a Rapidly Filling Horizontal Pipe. Journal of Hydraulic Engineering, 128(6), 635-639. doi:10.1061/(asce)0733-9429(2002)128:6(635)Vasconcelos, J. G., Wright, S. J., & Roe, P. L. (2006). Improved Simulation of Flow Regime Transition in Sewers: Two-Component Pressure Approach. Journal of Hydraulic Engineering, 132(6), 553-562. doi:10.1061/(asce)0733-9429(2006)132:6(553)Li, J., & McCorquodale, A. (1999). Modeling Mixed Flow in Storm Sewers. Journal of Hydraulic Engineering, 125(11), 1170-1180. doi:10.1061/(asce)0733-9429(1999)125:11(1170)Ramezani, L., Karney, B., & Malekpour, A. (2015). The Challenge of Air Valves: A Selective Critical Literature Review. Journal of Water Resources Planning and Management, 141(10), 04015017. doi:10.1061/(asce)wr.1943-5452.0000530Stephenson, D. (1997). Effects of Air Valves and Pipework on Water Hammer Pressures. Journal of Transportation Engineering, 123(2), 101-106. doi:10.1061/(asce)0733-947x(1997)123:2(101)Bianchi, A., Mambretti, S., & Pianta, P. (2007). Practical Formulas for the Dimensioning of Air Valves. Journal of Hydraulic Engineering, 133(10), 1177-1180. doi:10.1061/(asce)0733-9429(2007)133:10(1177)De Martino, G., Fontana, N., & Giugni, M. (2008). Transient Flow Caused by Air Expulsion through an Orifice. Journal of Hydraulic Engineering, 134(9), 1395-1399. doi:10.1061/(asce)0733-9429(2008)134:9(1395)Bhosekar, V. V., Jothiprakash, V., & Deolalikar, P. B. (2012). Orifice Spillway Aerator: Hydraulic Design. Journal of Hydraulic Engineering, 138(6), 563-572. doi:10.1061/(asce)hy.1943-7900.0000548Iglesias-Rey, P. L., Fuertes-Miquel, V. S., García-Mares, F. J., & Martínez-Solano, J. J. (2014). Comparative Study of Intake and Exhaust Air Flows of Different Commercial Air Valves. Procedia Engineering, 89, 1412-1419. doi:10.1016/j.proeng.2014.11.467Martins, N. M. C., Soares, A. K., Ramos, H. M., & Covas, D. I. C. (2016). CFD modeling of transient flow in pressurized pipes. Computers & Fluids, 126, 129-140. doi:10.1016/j.compfluid.2015.12.002Zhou, L., Liu, D., & Ou, C. (2011). Simulation of Flow Transients in a Water Filling Pipe Containing Entrapped Air Pocket with VOF Model. Engineering Applications of Computational Fluid Mechanics, 5(1), 127-140. doi:10.1080/19942060.2011.11015357Davis, J. A., & Stewart, M. (2002). Predicting Globe Control Valve Performance—Part I: CFD Modeling. Journal of Fluids Engineering, 124(3), 772-777. doi:10.1115/1.1490108Stephens, D., Johnson, M. C., & Sharp, Z. B. (2012). Design Considerations for Fixed-Cone Valve with Baffled Hood. Journal of Hydraulic Engineering, 138(2), 204-209. doi:10.1061/(asce)hy.1943-7900.0000496Romero-Gomez, P., Ho, C. K., & Choi, C. Y. (2008). Mixing at Cross Junctions in Water Distribution Systems. I: Numerical Study. Journal of Water Resources Planning and Management, 134(3), 285-294. doi:10.1061/(asce)0733-9496(2008)134:3(285)Austin, R. G., Waanders, B. van B., McKenna, S., & Choi, C. Y. (2008). Mixing at Cross Junctions in Water Distribution Systems. II: Experimental Study. Journal of Water Resources Planning and Management, 134(3), 295-302. doi:10.1061/(asce)0733-9496(2008)134:3(295)Ho, C. K. (2008). Solute Mixing Models for Water-Distribution Pipe Networks. Journal of Hydraulic Engineering, 134(9), 1236-1244. doi:10.1061/(asce)0733-9429(2008)134:9(1236)Huang, J., Weber, L. J., & Lai, Y. G. (2002). Three-Dimensional Numerical Study of Flows in Open-Channel Junctions. Journal of Hydraulic Engineering, 128(3), 268-280. doi:10.1061/(asce)0733-9429(2002)128:3(268)Weber, L. J., Schumate, E. D., & Mawer, N. (2001). Experiments on Flow at a 90° Open-Channel Junction. Journal of Hydraulic Engineering, 127(5), 340-350. doi:10.1061/(asce)0733-9429(2001)127:5(340)Chanel, P. G., & Doering, J. C. (2008). Assessment of spillway modeling using computational fluid dynamics. Canadian Journal of Civil Engineering, 35(12), 1481-1485. doi:10.1139/l08-094Li, S., Cain, S., Wosnik, M., Miller, C., Kocahan, H., & Wyckoff, R. (2011). Numerical Modeling of Probable Maximum Flood Flowing through a System of Spillways. Journal of Hydraulic Engineering, 137(1), 66-74. doi:10.1061/(asce)hy.1943-7900.0000279Castillo, L., García, J., & Carrillo, J. (2017). Influence of Rack Slope and Approaching Conditions in Bottom Intake Systems. Water, 9(1), 65. doi:10.3390/w9010065Regueiro-Picallo, M., Naves, J., Anta, J., Puertas, J., & Suárez, J. (2016). Experimental and Numerical Analysis of Egg-Shaped Sewer Pipes Flow Performance. Water, 8(12), 587. doi:10.3390/w812058