نوع مقاله : یادداشت فنی
نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
In designing the hydraulic structures with rapid flow, there is the probability of occurrence of cavitation phenomena. To prevent the occurrence of cavitation phenomena, the places where may pressure reduced to vapor pressure of liquid because of increase the flow velocity, should be identified. In this regard, to achieve a quantitative measure, the cavitation index can be used. In this study, two cases have been designed and simulated for Vanyar dam’s spillway using numerical models of computational fluid dynamics (CFD). Then the cavitation index was calculated for each case and finally for the verification, the results of laboratory model are used. For the numerical solution of the 3-dimensional Navier-Stokes equations and 3-dimensional gridding of the spillway, the Fluent and Gambit software are used, respectively. To determine the parameters of the flow field turbulence, the free-surface flow and the separation of momentum equations, the k – ? (RNG) turbulence model, the VOF method and the second order upwind method are used, respectively. The results indicated a proper agreement between the Fluent results and experimental model. Also it is found that in none of the considered cases, the cavitation didn’t occur and constructed spillway is safe against this phenomenon.
In designing the hydraulic structures with rapid flow, there is the probability of occurrence of cavitation phenomena. To prevent the occurrence of cavitation phenomena, the places where may pressure reduced to vapor pressure of liquid because of increase the flow velocity, should be identified. In this regard, to achieve a quantitative measure, the cavitation index can be used. In this study, two cases have been designed and simulated for Vanyar dam’s spillway using numerical models of computational fluid dynamics (CFD). Then the cavitation index was calculated for each case and finally for the verification, the results of laboratory model are used. For the numerical solution of the 3-dimensional Navier-Stokes equations and 3-dimensional gridding of the spillway, the Fluent and Gambit software are used, respectively. To determine the parameters of the flow field turbulence, the free-surface flow and the separation of momentum equations, the k – ? (RNG) turbulence model, the VOF method and the second order upwind method are used, respectively. The results indicated a proper agreement between the Fluent results and experimental model. Also it is found that in none of the considered cases, the cavitation didn’t occur and constructed spillway is safe against this phenomenon.
In designing the hydraulic structures with rapid flow, there is the probability of occurrence of cavitation phenomena. To prevent the occurrence of cavitation phenomena, the places where may pressure reduced to vapor pressure of liquid because of increase the flow velocity, should be identified. In this regard, to achieve a quantitative measure, the cavitation index can be used. In this study, two cases have been designed and simulated for Vanyar dam’s spillway using numerical models of computational fluid dynamics (CFD). Then the cavitation index was calculated for each case and finally for the verification, the results of laboratory model are used. For the numerical solution of the 3-dimensional Navier-Stokes equations and 3-dimensional gridding of the spillway, the Fluent and Gambit software are used, respectively. To determine the parameters of the flow field turbulence, the free-surface flow and the separation of momentum equations, the k – ? (RNG) turbulence model, the VOF method and the second order upwind method are used, respectively. The results indicated a proper agreement between the Fluent results and experimental model. Also it is found that in none of the considered cases, the cavitation didn’t occur and constructed spillway is safe against this phenomenon.
In designing the hydraulic structures with rapid flow, there is the probability of occurrence of cavitation phenomena. To prevent the occurrence of cavitation phenomena, the places where may pressure reduced to vapor pressure of liquid because of increase the flow velocity, should be identified. In this regard, to achieve a quantitative measure, the cavitation index can be used. In this study, two cases have been designed and simulated for Vanyar dam’s spillway using numerical models of computational fluid dynamics (CFD). Then the cavitation index was calculated for each case and finally for the verification, the results of laboratory model are used. For the numerical solution of the 3-dimensional Navier-Stokes equations and 3-dimensional gridding of the spillway, the Fluent and Gambit software are used, respectively. To determine the parameters of the flow field turbulence, the free-surface flow and the separation of momentum equations, the k – ? (RNG) turbulence model, the VOF method and the second order upwind method are used, respectively. The results indicated a proper agreement between the Fluent results and experimental model. Also it is found that in none of the considered cases, the cavitation didn’t occur and constructed spillway is safe against this phenomenon.
کلیدواژهها [English]