三次元内部流動様式を考慮した油圧シリンダ内部の一次元温度予測法

摘要

It is important to study a precise and practical way to predict temperature rise of oil hydraulic systems. It is interesting whether internal flow patterns have any effect on the temperature change in a cylinder. Nowadays, commercial CFD (Computational Fluid Dynamics) codes give accurate solutions of temperature as well as flow patterns. The authors have calculated the flow pattern in a cylinder using a reliable CFD code and have found that there is characteristic vortex flow with a strong three-dimensional effect on the flow pattern, and the internal flow patterns can be classified into two flow regions, a 3D vortex flow pattern and a 1D parallel flow pattern. So, it becomes possible to predict precisely and practically the temperature change in a cylinder by incorporating the difference of the internal flow patterns with a modeling method based on a lumped parameter system. A new method for prediction of temperature rise in a cylinder is proposed in this study.