A CFD Multidimensional Approach to Hydraulic Component Design

This paper presents a multidimensional approach to the hydraulic components design by means of an open-source fluid dynamics code.A preliminary study of a basic geometry was carried out by simulating the efflux of an incompressible fluid through circular pipes. Both laminar and turbulent conditions were analyzed and the influence of the grid resolution and modelling settings were investigated. A qualitative description of the internal flow-field distribution and a quantitative comparison of pressure and velocity profiles along the pipe axis were used to asses the multidimensional open-source code capabilities.Moreover the results were compared with the experimental measurements available in literature and with the theoretical trends which can be found in well-known literature fundamentals (Hagen-Poiseuille theory and Nikuradse interpolation).Further comparison was performed by using a commercial CFD code. Then, the analysis was focused on the simulation of a reference test case with abrupt section change geometries, such as the forward-facing step. The recirculating regions, the vena contracta position, the reattachment point and the pressure and velocity fields were investigated.The predictive capabilities of three turbulence models were also investigated. The standard k-ge model, including wall functions for the near-wall treatment, was compared with a low-Reynolds number model and the two zonal version of the k-gv model.Finally, the metering section of a hydraulic check valve was modeled, and the capabilities of both CFD codes in describing the component steady-state behavior were analyzed.

This paper presents a multidimensional approach to the hydraulic components design by means of an open-source fluid dynamics code. A preliminary study of a basic geometry was carried out by simulating the efflux of an incompressible fluid through circular pipes. Both laminar and turbulent conditions were analyzed and the influence of the grid resolution and modeling settings were investigated. A qualitative description of the internal flow-field distribution, and a quantitative comparison of pressure and velocity profiles along the pipe axis were used to asses the multidimensional open-source code capabilities. Moreover the results were compared with the experimental measurements available in literature and with the theoretical trends which can be found in well-known literature fundamentals (Hagen-Poiseuille theory and Nikuradse interpolation). Further comparison was performed by using a commercial CFD code. Then, the analysis was focused on the simulation of a reference test case with abrupt section change geometries, such as the forward facing step. The recirculating regions, the vena contracta position, the reattachment point and the pressure and velocity fields were investigated. The predictive capabilities of three turbulence models were also investigated. The standard k- ε model, including wall functions for the near-wall treatment, was compared with a low-Reynolds number model and the two zonal version of the k - ω model. Finally, the metering section of a hydraulic check valve was modelled, and the capabilities of both CFD codes in describing the component steady-state behavior were analyzed. © 2007 SAE International.