Pressure drop in a hydraulic directional control valve: case study

Plus d'informations

Year of project

2008

Location of project

Rhône (69) - France

Client

Bosch Rexroth

Summary

Context

While it’s easy to predict the head losses of a pipe or a simple singularity using a one-dimensional model, it’s much more complicated to accurately estimate the hydraulic behavior of a more complex system.

For example, many hydraulic networks are made up of several branches, complex geometrical singularities or successions of simple singularities in which the flow is not established. In such cases, analytical formulas and abacuses are no longer valid or do not exist, and CFD simulation enables precise characterization of the network’s flow/head loss relationships and singularity, as well as correct calculation of flow distribution in the network’s various branches.

Objective

In the case presented here, the study concerns a hydraulic distribution block used in excavators.

The aim is to support the customer in the design of the channels inside the distribution block, in order to minimize pressure drop: for the same level of pressure, a higher oil flow rate is obtained, and therefore higher speed.

Modélisation hydraulique – Pertes de charge dans un distributeur hydraulique

Simulation and results

3D modeling was used to determine the flow/head loss law for the various designs submitted, and to identify the most favorable configuration.

In general, CFD simulation enables us to accurately estimate the head losses of any hydraulic system, however complex. In addition, 3D modeling can be used to obtain the flow pattern to identify penalizing zones, and thus pave the way for mathematical optimizations leading to sometimes counter-intuitive designs.

To find out more about CFD modeling of hydraulic distribution blocks.