Abstract
Static pressure fluctuations are an important ingredient in turbulence, but little is known about it. We have developed the accurate pressure measurement technique. The results were carefully compared with DNS results. In this study this technique is extended into the pressure gradient measurement and two point correlation measurement. Also, new idea to correct the HR resonance and low frequency fluctuation is presented. The acceleration vector is given by N.S. equation as follows; a^^→=∇(p/ρ)+v∇^2u^^→. In a fully developed turbulence, the viscous damping term is small compared with the pressure gradient term, therefore, the acceleration is closely related to the pressure gradient, and particle acceleration is evaluated by measuring the instantaneous pressure fluctuations.
